---
title: 'The SECRET of Bulk Fermentation: Measuring Dough Temperature and % Rise - The Two-Factor Method'
source: 'https://youtube.com/watch?v=p69UMuYJhJs'
video_id: 'p69UMuYJhJs'
date: 2026-07-01
duration_sec: 3557
---

# The SECRET of Bulk Fermentation: Measuring Dough Temperature and % Rise - The Two-Factor Method

> Source: [The SECRET of Bulk Fermentation: Measuring Dough Temperature and % Rise - The Two-Factor Method](https://youtube.com/watch?v=p69UMuYJhJs)

## Summary

Tom from the International Institute for the Advancement of Sourdough Science explains that the common advice to let sourdough dough double during bulk fermentation is often wrong. He reveals that the true secret is synchronizing the percentage rise with the dough temperature, introducing a two-factor method for consistent results.

### Key Points

- **Doubling Advice is Wrong** [0:57] — The common guidance to let dough double in volume during bulk fermentation is completely wrong for most home bakers.
- **Temperature-Reliant Cut Off** [1:10] — The percentage rise in bulk fermentation must be related to the dough temperature, as warm dough needs to be cut off earlier.
- **Research Background** [3:02] — Tom's initial 2021 experiments showed a discrepancy between Chad Robertson's 30% rise at 80°F and other recipes recommending 100% rise at cooler temperatures.
- **Published Table** [4:22] — In January 2023, Tom published a table linking dough temperature to target percentage rise: 80°F = 30%, 70°F = 75%, 65°F = 100%.
- **End of Bulk = Beginning of Fermentation** [8:21] — The end of bulk fermentation is not the end of fermentation; yeast and bacteria continue fermenting during pre-shape, bench rest, final shaping, and cold retard.
- **Refrigerator Cooling Curve** [9:23] — After placing dough in the refrigerator, it takes about 10 hours to reach 39°F (4°C), with significant fermentation in the first four hours.
- **Javelin Throwing Analogy** [11:50] — Bulk fermentation is like running; the cold proof is like throwing a javelin. Warm dough requires a later cut-off (more run) but a stronger throw (more fermentation in the fridge).
- **Speeding Car Analogy** [15:43] — Warm dough is like a speeding car on a slippery road; you must hit the brakes (cut off bulk) earlier to avoid overproofing.
- **Required Tools** [19:54] — You need a digital probe thermometer (not infrared) and a measuring vessel with milliliter/quart markers. Ignore the clock—time will lie, temperature and percentage rise never lie.
- **Water Trick for Any Vessel** [20:57] — Any transparent vessel can be calibrated into a measuring tool by marking every 100g water addition (1g water = 1 ml).
- **Start Line Measurement** [21:07] — Mark the starting volume of mixed dough (e.g., 750 ml for a 500g flour batch). For standard recipes, starting volume ≈ 1.5 × flour weight in grams (in ml).
- **Vessel Sizing Rule** [23:37] — Your vessel should hold at least 3× your flour weight in ml to allow for doubling. For 500g flour, use a 1.5L+ vessel.
- **Ending Dough Temperature Matters Most** [30:32] — If dough temperature changes during bulk, use the ending temperature when cutting off bulk fermentation, as that determines downstream fermentation.
- **Option to Calibrate Your Schedule** [32:22] — By controlling dough temperature with a proofer (warm or cool), you can time fermentation to fit your schedule. Controlled temperature = controlled time.

### Conclusion

Mastering bulk fermentation is about ignoring time and instead measuring dough temperature and percentage rise. By using the temperature-rise chart, you achieve perfectly proofed dough every time.

## Transcript

[Music]
hi I'm Tom coming to you from The
International Institute for the
advancement of sourdough science and
research of Cleveland Ohio also known as
my kitchen thank you for selecting this
video in today's video we're going to
talk about one of the biggest challenges
souro Bakers have and that is trying to
figure out when do you cut off off bulk
fermentation this is the most
challenging aspect of sourdough baking
I've done dozens of videos on this topic
and people still continue to struggle
with it now if you look at the most
popular recipes that are out there many
recipes will give very simplistic
guidance that says you mix your dough
you do your stretch and folds and that
you let then you let your dough rise at
room temperature until it doubles in
volume what I'm going to show you in
today's video is that that guidance is
completely wrong I've done a number of
experiments over the years and I've
proven that the percentage rise in bulk
fermentation that you're looking for is
related to the dough temperature warm
fermenting dough needs to be cut off
earlier than cool fermenting Dough
because that dough keeps fermenting in
the downstream steps after bulk
fermentation is done it keeps fermenting
and pre-shaping bench rest final shaping
and then when the dough goes into the
refrigerator typically for a cold
the dough keeps fermenting so that
ending temperature of the dough
determines what happens after bulk
fermentation so you need to synchronize
the percentage rise with the dough
temperature this is the biggest secret
of sourdough bulk fermentation I'm going
to explain it here
today
now before we jump into the details I
just want to reply to the people who've
been asking about brother Bob now for
those of you who watch my videos you
know that brother Bob was here around
the 4th of July and we were filming the
sourdo brothers souro for busy people
video and Bob suffered a head injury in
my kitchen during the filming of that
video brother Tom I'm so happy to be
back Bob's doing okay he's back in
California he's back at his teaching job
but Bob's having a little trouble with
his memory Bob thinks that somehow when
he was here he was involved in an Amish
barn raising I have no idea what he's
talking about but I think Bob's going to
be fine and we're looking forward to
creating more sourdo Brothers videos in
the
future now let me give you some
background on this question of when do
you cut off bulk fermentation as people
know I've been doing research on this
for years the first time I looked into
this was in
2021 when I did two videos in my when is
bulk fermentation done series episode 7
and episode 8 and what I was looking at
at that time was this discrepancy
between recipes where things like the
Chad Robertson tarene country loaf
recipe that I follow religiously
recommends a 30% rise in the dough in
bulk fermentation and then many other
popular recipes were recommending 100%
rise in the dough and I couldn't figure
out how is that possible in those
experiments I found the first glimpse
into this issue that the percentage rise
in the dough needs to be correlated with
the dough temperature warm dough needs
to be cut off earlier than cool dough so
in this example I cut off Chad
Robertson's recipe at a 30% rise which
is what he recommends because the dough
temperature he recommends is 80° fenhe
or 27° C that's a very warm fermentation
temperature then I compared that to
other recipes that were bulk fermenting
at 70° F or 21 de c those could tolerate
a much higher percentage rise in the
dough and I was able to produce the
exact same results at the end so I
continued doing experiments and in
January of 2023 I published this article
the mystery of percentage rise and bulk
fermentation you can find this on my
website and you can find this in the
description of the video this was
usually a breakthrough where I put all
the science together and in this
document I published this table which I
had proven through multiple experiments
that shows when you bulk ferment at warm
temperatures you need to cut off the
dough earlier when you bulk ferment at
cooler temperatures you can go for a
higher percentage rise so what you can
see on this chart is if your dough is
bulk fermenting at 80° fahr you cut that
off at a 30% rise if your dough is bulk
fermenting say at 70 Dees Fahrenheit the
third line here you cut that off at a
75% rise and the only time you go for
100% rise is if your dough is very cool
lower than 70° Fahrenheit or 21° C in my
experience it needs to be around 65°
Fahrenheit or 18° Celsius to tolerate
100% rise in the dough this chart has
been cut and pasted out of my document
and shared tens of thousands of times on
social media this is the most shared
piece of content on social media right
now around bulk fermentation really
around sourdough baking in general
everybody is sharing this content
because this is a breakthrough it
refutes the general guidance of just let
your dough double at room temperature if
you do that generally speaking your
dough will overproof and I've seen this
in many many examples hundreds of people
over proofing their dough every month
because they're following the simple
simplistic and an inaccurate guidance of
just letting your dough
double so now you might be asking the
question how does this actually work
here's how it works you mix up your
dough and when all the ingredients are
initially mixed you're going to put that
in a measuring vessel and you're going
to measure your starting volume of dough
then you do your stretch and folds you
let your dough rise and as the dough is
rising you take the temperature of your
dough my D is at 70° f 21° c so I
consult my handy chart that says at 70°
Fen 21° C I'm looking for a 75% rise in
the dough so I take my starting volume I
multiply that by
1.75 and I put this second marker on my
measuring vessel and I wait for the
dough to hit that percentage rise when
the dough hits that percentage rise it's
perfectly fermented then I shape the
dough I pre-shaped the dough I let it
rest for 30 minutes I final shape the
dough I put it into the refrigerator I
take it out the next day anywhere from 8
to 16 hours after it's been in the cold
in the refrigerator and the dough
is perfectly proofed and this works at
any temperature if you synchronize the
percentage rise with the
temperature here are some examples 80°
dough cut off at a 30% rise perfectly
proofed 75° dough cut off at a 50% rise
perfectly proofed 70° D cut off at a 75%
rise perfectly proofed 65 degree dough
cut off at a 100% rise perfectly
proofed this method works and what you
can see is the only time you want your
dough to double in volume is when your
dough is very cold in my example 65° f
21° c so all the guidance out there
there that says let your dough double at
room temperature if if your room
temperature is above 65° F which it
usually is in most people's kitchens
your dough is going to
overproof so now you ask the question
how does this work and the reason this
works is because we tend to think of
bulk fermentation as the end of
something I mean we call it that the end
of bulk fermentation but you need to
think of that as the beginning of
something the end of bulk fermentation
is the beginning of the rest of the
fermentation process so when you cut off
bulk fermentation that's an arbitrary
point the yeast doesn't know bulk
fermentation is over lactic acid
bacteria doesn't know bulk fermentation
is over they're just going to keep
fermenting so you cut off bulk
fermentation then you pre-shape the
dough you let it rest on the countertop
for 30 minutes you final shape it during
that 30 minutes or so that dough is
still rapidly fermenting it doesn't no
bulk fermentation over then when you put
that dough into the refrigerator it
takes 10 hours for the dough to get down
to the refrigerator temperature a lot of
people assume I mean it's easy to assume
you put that dough in the refrigerator
and it just immediately stops fermenting
and it goes down to the refrigerator
temperature that doesn't happen here's
what actually happens take a look at
this
chart if we take our 80° Fahrenheit
dough 27° C we pre shape it bench rest
it final shape it that dough temperature
drops to about 78° F before it goes into
the refrigerator it goes into the
refrigerator and for the first hour that
dough is still rapidly fermenting it's
it takes an hour to get down to 70°
Fahrenheit or 21° C which is a lot of
people's kitchen temperature the dough
thinks it's still fermenting at room
temperature then in the next 3 hours
that dough drops from 70° F to about
about 50° F 10° C that's still a fairly
moderate fermentation range there is
real fermentation happening there in
those 3 hours then the next 3 hours the
temperature drops from 50° F to about
41° Fen or 5° C the dough is still
slowly fermenting and then in those last
3 hours it drops from 41 degrees
Fahrenheit to 39 degrees Fahrenheit or 4
degrees celsi and that's where the yeast
finally goes to sleep and it starts
fermenting very very slowly it never
actually stops in the refrigerator but
when it hits 39° fah or 4° C you can
consider it to be very very slowly
fermenting so now if you look at this
chart you can see what's happening when
you put very warm dough into the
refrigerator there are two things that
dough is rapidly fermenting before it
goes into the refrigerator because the
fermentation rate is related to the
temperature 80° fah dough 27° C is
rapidly fermenting so it goes in moving
very quickly and because it's a warmer
temperature it takes a longer time for
the temperature to get down to 39° F or
4° C where the the yeast goes to sleep
so you get a lot of fermentation
happening in the refrigerator contrast
that with very cool dough 65° Fahrenheit
dough 18° C it goes in at a slower rate
of fermentation because it's cooler
going into the refrigerator and it goes
in at a lower point on the curve so it
hits the refrigerator temperature more
quickly and the yeast goes to sleep more
quickly so the cool dough ferments much
less in the refrigerator so that's where
this formula basically makes sense
you're doing the same amount of
fermentation between bulk fermentation
and the final proof proofing but the
amount of fermentation happening in bulk
fermentation versus in the refrigerator
is different based on that dough
temperature and when you cut off the
bulk
fermentation if you want to learn more
about the science behind this chart
there's a link to the article in the
description of this video and you can
find it on my website at the sourdo
journey.com
so when I think about that cut off of
bulk fermentation I think of it a lot
like as if you were throwing a javelin
when you throw a javelin the moment it
leaves your hand you have no control
over what happens that's the cut off of
bulk fermentation once you decide that
cut off basically you have no control
over the dough going forward until it
comes out of the refrigerator when you
throw a javelin the thing you do have
control over is the speed of your hand
and that trajectory of the javelin that
determines where it will land so you can
imagine for warm dough where I'm bulk
fermenting at 80° fah but I'm doing that
cut off at a 30% rise I have a long
distance to cover so I need a lot of
speed and a steep trajectory to get the
javelin to land in the right place if
I'm bulk fermenting at cool temperatures
that dough is fermenting more slowly so
my hand speed is slower and I've already
achieved a higher percentage rise so I'm
releasing it at a lower trajectory both
of those javelins will land in exactly
the same place so here's an example of a
javelin throwing competition where we
have two throwers but in this unique
competition each one of them can decide
how far they want to run down the field
before they stop that's the end of bulk
fermentation and then they throw the
javelin from there that's the cold
so the first thrower represents
our 80° Fahrenheit dough which we would
bulk ferment to a 30% rise so this
thrower runs down the field 30 m towards
the target then he stops that's the end
of bulk fermentation but this thrower
has a very strong arm because at that
80° Fahrenheit dough temperature the
dough is fermenting very quickly so he
can release the javelin with a fast hand
speed and a high trajectory and he can
make the distance to the Target doing
most of the fermentation after the end
of bulk fermentation compare that to the
second thrower he represents the 70°
fahit dough that we would bulk ferment
to a 75% rise before the cut off he runs
75 M down the field he needs to get
closer to the Target because he has a
weaker arm the dough temperature is only
70° Fahrenheit so he doesn't have the
same hand speed or that same trajectory
so he goes closer to the Target the 75%
rise then he releases his Javelin it
lands in the exact same spot so what you
can see with this example is that both
the javelins travel the same distance
they just get there through different
means part of the way is through running
and part is through throwing the running
is the bulk fermentation the throwing is
the cold and what you see with
warm dough the 80° Fahrenheit dough that
travels a long distance in the air
during the cold a lot of
fermentation is happening in the
refrigerator and with cooler dough less
of the fermentation is happening in the
refrigerator but they both land in the
same place but once it leaves your hand
you have no control over it its outcome
is predestined once you decide that cut
off of bulk
fermentation here's another example
trying to determine that cut off of bulk
fermentation is like trying to figure
out if you're driving a speeding car on
a slippery Road and you see a stop sign
up ahead when do you need to hit the
brakes that's the cut off of bulk
fermentation and you can imagine if
you're driving really fast you need to
hit the brakes earlier because you're on
a slippery Road and you're going to
start skidding when you hit the brakes
so you need a longer stopping distance
if you're traveling more slowly you can
wait later to hit the brakes because you
have a shorter stopping distance the
speed of the car is the equivalent of
the bulk fermentation dough temperature
warm dough ferments very quickly
compared to cold dough so here's a live
example of the speeding car we're going
to have Santa with a couple of his
reindeer in his tricked out Chevy low
rider here Santa's going to be driving
his car from the beginning of bulk
fermentation that's this blue line here
this line would be 100% rise in bulk
fermentation and then the stop sign that
Santa sees ahead is this big red dutch
oven that's after shaping and the cold
in the refrigerator which was
represented here and that's when when
the dough is going to get into the oven
so basically you're speeding through
bulk fermentation you want to hit the
brakes on the slippery Road and you're
going to slide in here to stop right
before it goes into the oven at the stop
sign here's Santa he's going to be going
80 M hour that's 130 km per hour and
let's assume that's the equivalent of a
80° fah dough temperature 27° C based on
our chart that means Santa needs to hit
the brakes on the slippery Road at the
30% rise Mark which is way back here
early and bulk fermentation because he's
going so fast and he's used to driving a
sleigh this car has rear wheel drive it
doesn't have antilock brakes this is not
going to be pretty so if Santa's driving
80 M an hour and let's say he doesn't
know about that chart he comes flying
through bulk fermentation and he does
100% rise like you read in some recipe
and he hits the brakes here he skids out
of control there's a rollover accident
Christmas is cancelled I mean this is
the real you're Without a Santa Claus
this is a Christmas tragedy so if you go
too far in your bulk fermentation at a
warm temperature your dough is going to
over
prooof then we say Santa check out the
chart dude 30% rise you need to hit the
brakes right here so Santa comes
speeding into bulk fermentation at 80 M
hour now he hits the brakes here he goes
into a skid he's going past the 100%
rise Mark and he Parks it right next to
the stop sign goes into the Dutch oven
and gets baked into a perfectly proofed
loaf of bread because he hit the brakes
earlier which he needed to do because he
was driving so quickly here's another
example Santa got a speeding ticket need
to slow down lead foot Santa so now he
only drives at 40 mph that's half the
speed he was at before and that's
actually the equivalent of about this
70° fenhe or 21° C temperature that's
almost half of the fermentation speed of
the 80° F dough it's much much slower
just in that 10° fhe difference so now
Santa's cruising along at 40 m per hour
that's 65 km per hour he's taking his
time he sees a stop sign up ahead here
he's got a lot of safe stopping distance
so he's going to go for a 75% rise based
on the chart so he hits the brakes here
he cruises through slides it in boom
right into the stop sign Santa goes into
the oven and makes a perfectly proof
loaf of bread for Christmas dinner so
warm dough is just like a speeding car
you need to hit the brakes early to
ensure that you have a safe stopping
distance if you want to learn more about
this speeding car example there's a link
to the article in the description of
this video and you can find it on my
website at the souro journey.com
now that you understand this in theory
let's talk about how do you put put this
into practice so most sourdough recipes
will tell you you need some specialized
tools for sourdough baking you need a
digital kitchen scale you need a l you
need a banatan you need a dutch oven but
what they don't tell you you need is a
digital probe thermometer to take the
temperature of your dough during bulk
fermentation and you need a measuring
vessel to measure the change in volume
which is the percentage rise in the
dough in bulk fermentation here's an
example of a measuring vessel this is a
large one here's a small one there are
all kinds of measuring vessels you want
to find something with milliliter or
leader or qut markers on it that's how
we're going to measure the percentage
rise in the dough it's the change in
volume which is measured in liters or
quarts you can buy small kitchen storage
vessels like this one this has Mill
markers on it this is perfect for bulk
fermenting one small batch of dough if
you work in a laboratory you could
borrow one of these scientific beakers I
like to use this that's a 3 l Beaker I
can do a two loaf rise in that vessel so
anything with milliliter markers on it
this is the one I showed earlier this is
a what's called a batter bowl it's
basically like a bowl with a handle but
that has the milliliter markers on it as
well there are a lot of kitchen vessels
out there you need to find one of those
and the important thing we don't need is
a
clock with this method you ignore the
time you have absolutely no use for this
device put it away step away from the
clock no need to measure the time let me
go back and talk about this chart
because I've been talking about the way
you do this is measuring the dough
temperature and the percentage rise and
if you read the whole document those are
the two variables that you need I show
the timing on this chart just so people
can understand how much longer the dough
will take to rise if you're bulk
fermenting at these low temperatures but
you never use the time to determine when
bulk fermentation is done the time will
lie to you the temperature and
percentage rise never lie it's
impossible it's physically impossible
for them to lie the clock will lie
because certain starters will rise
faster or slower than others different
flower will rise faster or slower than
others if you have different recipes
that you're using they'll rise faster
and slower so you can never rely on the
time
only rely on the temperature so I use
this chart just to show the relative
time but we are not going to use
this ignore the time this is all we need
for the rest of the process temperature
and percent rise gives you 100%
reliability and it's repeatable no
matter how long it
takes so this is the point in the video
where you might be saying to yourself
wow this sounds so simple how come I
never heard of this
before because most popular recipes are
wrong I don't know any other way to say
it I looked at the top 10 most popular
sourdough recipes out there and eight of
the 10 say mix your dough do some
stretch and folds and then let your
dough rest at room temperature until it
doubles in size that is the instruction
for bulk fermentation in eight of the 10
most popular sourdough recipes that
instruction is wrong let's just talk
about it the first part let your dough
rise at room temperature I mean what the
heck is room temperature I mean my
temperature in my kitchen right now is
74° fah if I lived in Australia right
now my kitchen temperature would be 90°
fenhe or 32° C if I lived in Finland
right now my kitchen temperature would
be 50° F or 10° C so any recipe that
tells you to do something at room
temperature is completely meaningless
because room temperature can be an
incredibly wide
variation the second problem with these
recipes is they say let your dough
double which isn't a bad concept but
they don't actually measure the doubling
if you watch those videos and look at
the photos in the recipes they're using
a bowl like this with their dough in it
and they show a picture that says okay I
let my dough double at room temperature
and they show a picture of a puffed up
ball of dough that's not actually
doubled there's no way to tell if it's
actually doubled let me say it that way
doubling is a mathematical concept if
you went into your boss's office and
your boss said congratulations I'm going
to double your salary you know what that
means it's two times your salary that's
what double is if your child is 3T tall
and they grow to be 6 feet tall you
would say oh my gosh my child has
doubled in height it's a measurable
thing unless you're a Sourdough Baker
and then doubling means I look at my
dough and it's kind of puffed up and if
I feel like I'm ready to go to the next
step I just decide it's doubled that's
how these recipes work but you say but
these Bakers they then show on the video
the dough comes out perfectly it's
because they're eyeballing the dough
they're using other criteria that
they're not explaining to you they're
smelling the dough you can't even see it
but they're smelling it they're shaking
the dough they're using the same bowl
that they always use so they can tell if
the dough is touching the side of the
bowl at a at a specific point but that
dough I'm telling you is not doubling
unless the dough temperature is below
70° fenhe 21° C otherwise their loaves
would overproof so it's just a lazy way
of doing instruction I don't know any
other way to to say it and I hate
criticizing other sourdough Bakers and
instructors but telling people to let
your dough double at room temperature is
lazy and it's usually wrong now there
are two notable exceptions when I said I
looked at the top 10 uh recipes that
people
use look at this one Chad Robertson
taram bread my favorite recipe in the
world Chad Robertson is one of the two
that does provide do temp in percentage
D he specifically says during bulk
fermentation the dough temperature
should be between 78° F and 82° F that's
25.5 to 28 deges
C and he tells you the percentage rise
between 20 to 30% rise in the dough when
you cut off bulk fermentation that's
exactly where my studies came out here
for 80° dough 27° C you go for a 30%
rise Chad Robertson had this figured out
in 2006 he told people how to do it the
other
example very popular recipe from elain
body elain tells you let your dough
double in size but she gives you the
specific dough temperature 18° C to 20°
C which is 64° f to 68° F which is
exactly what I found in my studies at 65
degree do temperature which is right
where Elaine's uh recipe is you go for a
100% rise in the dough elain's method
works and Elaine even tells you what
bowl to use she specifies this bowl I
went out and bought this and she says if
you follow her recipe and you let the
dough rise up to this line below the rim
that'll be 100% rise in the dough I
actually measured this I put it on a
scale and I measured the milliliter
volume up to that line it's actually
about 113% rise in the dough not 100%
but that's well within the realm of a
rounding error when you're trying to to
measure the percentage rise in the dough
so Elaine good job Chad Robertson good
job because they told you the dough
temperature and the percent rise in bulk
fermentation these are two of the most
popular and most successful recipes out
there and it's not a coincidence the
other eight people I think you have some
work to do on your
instruction and this is the point in the
video where you might say wow this Tom
guy sounds like a cranky old dude
criticizing other people's recipes let's
roll back the clock 5 years to
2018 check out Jack Sturgis from the
bake with Jack YouTube channel Jack is
the opposite of a cranky old dude and
five years ago Jack made this video
called leave your D to double question
mark and in that video Jack basically
said telling people to let their dough
double in bulk fermentation is nonsense
and and any recipe that recommends that
is a bad recipe now Jack did not in that
video say the way to do it is by
measuring the temperature and the
percentage rise he described the
techniques for reading the dough and
this is what a lot of expert Bakers rely
on they shake the dough they smell the
dough they look at the Dome they go like
this and that Baker's intuition is
basically what they're using but as a
proxy they're telling you that the dough
has doubled just because that's a easy
way to describe a puffed up ball of
dough that they've expertly assessed to
be finished with bulk
fermentation but with this method you
don't need to be an expert read the
chart temperature percent rise tells you
when bulk fermentation is
done now let's talk about how we
actually do this measuring the dough
temperature and the percentage rise
dough temperature is easy you need a
digital kitchen probe thermometer like
this you're going to take your bowl of
dough and you're going to put that probe
right in the center of the dough that's
your true fermentation temperature
mine's sitting at 70° F and a lot of
people are nervous about poking their
dough with this thermometer you can poke
poke poke it's not a balloon you're not
going to deflate your dough by taking
the temperature I even do it every half
hour sometimes it has no detrimental
impact on the dough by poking it with a
thermometer so I have 70° fhe 21° C D
the other thing I like to know is what's
my kitchen temperature so I also keep a
small thermometer in my kitchen this is
at 74° F which is about 23° C because as
my dough is fermenting if I'm not
keeping this in some kind of proofing
chamber the dough temperature is
ultimately going to try to equalize with
your kitchen temperature so you always
want to be aware of that difference so I
know the longer this do sits out at 70°
f it wants to be at 74° F why does this
create a problem because if people use
thermometers like this these infrared
thermometers these just test the surface
temperature of the dough and if I let
this sit here for about a half an hour
the surface temperature of the dough
will say 74 Dees fah which is my kitchen
temperature really quickly but the true
fermentation temperature of the dough in
my opinion is always that temperature at
the center that's what you want to use
when you're looking at the chart it's
the temperature at the center of the
dough another question people ask is
what if the dough temperature changes
over time because you're bulk fermenting
over a long period of time let's say I
mix this dough at 70° Fahrenheit but it
ends up at 75° fahren which number on
the chart should I use should I use 70
should I use 75 should I use 72 1/2 the
average the most important temperature
when you're using this method method is
the ending dough temperature and you
know why because that is when the
javelin is released from the hand the
ending dough temperature is what carries
forward into pre-shaping bench rest
final shaping and into the refrigerator
and that Downstream impact of the
fermentation that perfectly proofs it is
based on the temperature as the dough
goes into the refrigerator so if your
temperature changes over time use the
ending temperature
so now for measuring the percentage rise
in the dough let's talk about the
fermentation vessels I showed some
examples earlier these are great
examples because these have liters or
quarts or cups marked on them I tend to
do it in liters or milliliters that's
what you want to measure the volume in
if you're doing a small batch of dough
you can even use these small Pyrex
containers those have milliliter markers
on them I like this one this is a 2 L
vessel with milliliters on it you can
buy all these things with milliliters on
them that's the best way to do it
milliliters are the way that you measure
the change in volume that's the metric
system equivalent of of cubic inches or
cups I guess in the US system or the
imperial system but you always want to
use milliliters that's the true measure
of volume and you want to have that
accuracy which is it's a more accurate
measurement than using cups or
quarts and then some some people say
come on do I really need to measure in
milliliters I mean does it need to be
that accurate can't I just use my trusty
bowl and Eyeball this to tell when it
doubles let me ask you a question if you
went to a golf class and the golf
instructor said you only need to bring
one thing to class you need to bring a
golf club and you show up at the class
and you say I don't have a golf club but
I have this stick and I really think I
could play golf with this stick they
would say that is not the tool to play
golf with you can't take the class with
a stick and then if you went to a
baseball school and they said you need
to bring a baseball mitt and you showed
up with you know a kitchen oven glove
and it's even on the wrong hand and
you'd said I'm good I got my mitt here
they would say you can't play baseball
with an oven mitt you need a basball
mitt but with sourdough baking for some
reason when people say you need to
measure the percent rise in milliliters
people say I'm good got my bowl got my
bowl right here I can tell when this is
double it's impossible to tell when your
dough doubles in a bowl like this and
then you might say okay Marty what about
this bowl where I can actually look
through the side of it because then I
can tell the height change in this and
if the height doubles that would be a
doubling of my dough wrong
answer the doubling of the dough is
measured in milliliters not in height
because if your bowl flares out on the
side like this the first 3 in of height
is about 1/3 of the total volume of the
bowl and the second 3 in of height is
2/3 of the volume of the bowl so there's
no way to measure the percent change in
volume the perc rise in the dough using
a flared out bowl like this just by
eyeballing it you can't just look at
engage it based on the height however if
you have a perfectly straight sided
vessel like this you can use this but
you need a ruler so here if you have
straight sides on the vessel you can
measure the height because then the
change in height is the change in volume
only with a perfectly straight sided
vessel so take a ruler put a piece of
tape on here and measure this either in
inches or centimeters I recommend doing
it in centimeters because the math is a
little bit easier to do you can turn
this into a measuring vessel I do this
all the time and then some people still
say not going to do it not going to go
out and buy a straight-sided vessel
because I got my bowl I just want to use
my trusty bowl there is a way you can
make any shape or size vessel into a
milliliter measuring vessel by doing
what I call the water trick here's how
you do it take any shape or size vessel
as long as it's transparent you need to
be able to see through it and you're
going to put a piece of tape on the side
of this vessel then you're going to put
that on the scale you're going to zero
out your scale and you're going to pour
in 100 G of water at a time 100 G of
water equals 100 ml that's how the
metric system was designed it's around
the density or the volume of water so gr
equals milliliters only for water not
for other liquids I put in 100 Mill of
water I marked my first hash mark I put
in another sorry I said milliliters it's
the same 100 G more now I'm up to 200 I
put my hash mark on the
tape then when you finish filling this
up to the top you're going to pour the
water
out and then using your best penmanship
you're going to write in those
milliliter markers 100 200
that's a 2400ml bowl that's 2.4 L I did
not know that and now I have another
measuring vessel in my kitchen that I
can use to measure the percentage rise
in my
dough so now people ask how do you
measure that starting volume of the
dough what what is that starting line so
the starting line is the volume of the
dough after all the ingredients have
been mixed together a lot of recipes you
mix everything together at the same same
time some of them delay adding the
starter they delay adding the salt they
delay adding some water so you want to
wait until you have all the ingredients
in the bowl once they're in the bowl
then you're going to move that into your
measuring vessel to mark your starting
line so I'm going to do that right here
this is my mixed dough has all my
ingredients in it I move that into my
measuring vessel and I want to Pat this
down so that it's level you want to do
the best you can I mean it's dough it's
not going to be perfectly level but you
get that level then you look through
your milliliter markers on the side of
the bowl and you measure your starting
volume and this is
750 Mill so I'm at 750 I put a piece of
blue tape on the side of that bowl where
my starting volume
is that's my starting line now you look
at this and say Tom this is a little
crazy you mix this the dough in this
bowl then you put it in this bowl but
now I still need to do my stretch and
fold or my coil folds or whatever what
do you do I take the dough
out and I put it back
in my larger Bowl where it's easier to
do the coil folds stres and folds
whatever and I don't have to worry about
this start if this starts rising in that
bowl because I already know my starting
line and the other really interesting
thing is once you do this for a given
recipe it's always exactly the same the
volume of the mixed dough is the same
for recipe so you only have to do that
transfer one time and now I know my
starting line is 750 if I mix this exact
same bash tomorrow or a month later or a
year later the starting volume is always
750 so write that down on your recipe
card or sheet so you always know what
your starting volume is then you don't
have to do this transfer you just Mark
the bowl when you mix the dough there's
another great trick or shortcut you can
use I've done this many times hundreds
of times where I've mixed the dough I
moved it into the measuring
vessel the volume of the mixed dough if
you're following a standard sourdough
recipe with 75% hydration 20% starter
inoculation 2% salt salt it's kind of
the standard recipe that you find a lot
of times that dough mixes up at 1.5
times the flour weight in milliliters so
if I'm mixing a 500 G batch of dough I
take 500 * 1.5 that's 750 look what
number I have here 750
it's 1.5 * the weight in g equals the
milliliters that really works I mean
that will get you very close a lot of
the time and again once you validate
that for a recipe it never changes so I
use that when I'm doing my routine
recipes over and over again if I'm
making a recipe for the first time I
might actually move it into the bowl and
Mark that starting line rather than
doing the 1.5 Rule now related to this
some people will say how do I know how
big of a vessel I need for my bulk
fermentation because I showed you some
examples here how did I decide whether I
was using this small one or this bigger
one I needed this bigger one because I
have to allow for the dough to rise and
the way to calculate that is you want to
take three times your flower weight in
grams and that will equal the maximum
height that you need in your vessel in
milliliters for the dough to double in
size if you wanted it to double which is
uncommon but that gives you some head
room so here's the example 500 G flour
weight recipe * 3 tells me the
milliliters I need if that dough were
going to double in volume 500 *
3,500 so I need at least a 1,500ml
vessel or 1.5 L vessel this vessel
happens to be 2,000 M or 2 L so I have
plenty of Headroom in this vessel that's
how you size it use that rule of three
times the flower weight so so now I know
my starting point I have my dough in my
stretch and fold Bowl I'm doing my
stretch and folds I'm doing my coil
folds the dough starts Rising do I need
to worry about that you don't need to
worry about that because it's never
going to hit your target before you
finish the stretch and fold that would
be incredibly uncommon so do your
stretch and folds then once your stretch
and folds or coil folds are done you're
in the middle of bulk fermentation here
that's when you're going to carefully
take your bulk fermenting dough out of
your stretch and fold vessel and put it
in into your measuring vessel and you're
not going to touch this until it's done
so I carefully take my dough out I put
it in my measuring
vessel now we can figure out what is the
target percent rise that we're looking
for how do we do
this I take the dough temperature and
the dough temperature will tell me the
Target percent rise I take my dough
temperature 70° f 21° c I look at at my
chart 70° f 21° c needs a 75% rise in
the dough how do I get that number I
know my starting line was 750
milliliters so I take that starting line
times
1.75 that's a 75% increase 750 * 1.75 I
think is
13125 mlit computer what's 750 * 1.75
5 good afternoon Tom 750 * 1.75 is
13125
13125 so I Mark that on my
tape I find that measurement on my
vessel to the top of the tape to the
best of my
ability that's my 75% rise now I walk
away I go do chores I go watch TV I'm
not doing anything here I'm not watching
the clock at all all I'm doing is
watching the dough and when that dough
Rises and hits that line the top of that
tape 13125 MERS that's a 75% rise bulk
fermentation is done shape it pre-shape
bench rest final shape put it in the
refrigerator for 8 to 16 hours bake it
the next day it's perfectly
proofed
now a lot of people ask questions and
ask how do you measure that ending
volume because as the D is rising it
domes up on the top you can see that
here in this example for sure that's the
natural way that this D will rise so
what I typically do is you have two data
points you can look at look at what's
the milliliter marker where the dough is
touching the side of the bowl and then
you look through the bowl and say what
would the milliliters be if I could lay
something flat on top of the top of the
Dome and you so you have those two
numbers and basically split the
difference between those so in this
example if I have the side of the dough
tou ing my vessel right now at 1,000 ML
and the top of the Dome is at 1100 ml
I'm going to call that 1,50 mlit where
I'm just splitting the difference
between the two another way to think
about it is if at that exact moment in
time that dough liquefied the sides
would come up and the top would go down
so splitting that difference is very
similar to using that liquefication
example it has to be higher than the
outside edge top touching the bowl and
it has to be lower than the Dome just
pick the midpoint it's close
enough then people ask the question they
say oh my gosh I was watching TV the
dough kind of ran away from me I didn't
catch it right at the moment of
13125 ml did I ruin my dough you didn't
you have a window to let the dough go
past the these estimated percentage
Rises but it's related to the
temperature and again this goes back to
the speed of fermentation is related to
the temperature of the dough so let's
say for example in this case I'm looking
for a 75% rise in this dough at at 70°
fah 21° C that's a fairly cool bulk
fermentation temperature so you have a
bigger margin of error on cool dough so
let's say I'm going for a 75% rise this
could go up to 80%
85% I mean may maybe even up to 90% this
dough would still be okay because it's
relatively cool with warm dough 80° F
27° C you have about a 5 percentage
Point margin I'm serious I mean it is
really tight if this called for a 30%
rise and you you let it go to 50% it's
overproofed you let it go to 40% it's
right on the edge of overproof maybe you
can go 30 to 35% rise to get it
perfectly proed
so that window your margin of error
depends on the dough temperature cooler
dough you can overshoot the target
more so we're almost there your dough
has perfectly risen you've done
pre-shaping bench rest final shaping the
dough has gone into the refrigerator
from 8 to 16 hours and some people will
say wow 8 to 16 that's a pretty large
window go back to this
chart after eight hours the fermentation
is largely done I mean you're down here
at 40° F 4.4 de C very very slow
fermentation so the difference between 8
hours and 16 hours is very minimal
fermentation activity happening so you
have a big window on the back end of
that refrigerator final proofing time
which is great if you're trying to work
around a busy schedule I've left my
dough in the refrigerator for up to 3
days and baked it as you start to go
past 24 hours the thing that you want to
think about because that dough is still
very slowly fermenting if you start
adding days instead of one day you go to
two days two days you go to three days
each day that you add in the
refrigerator is a little bit I'm going
to make a gross generalization it's a
little bit like adding an extra hour of
bulk fermentation so your dough will
continue to proof in the refrigerator
but you have a wide
window but the refrigerator temperature
is an important part of this formula so
we've been really hyperfocused on our
dough temperature during bulk
fermentation and our percentage
rise what if your refrigerator
temperature is too warm I mean this
happens in the summer you have kids
going in and out of the house they're
opening the refrigerator they're leaving
it open for 10 minutes at a time if you
have dough in there and your
refrigerator is warmer than you expect
it to be this chart doesn't get down to
40° Fen or 4° C very quickly it's going
to stay a little bit higher than that
your dough can overproof in the
refrigerator because of the refrigerator
temperature not because of where you cut
it off for final proofing so those two
things are closely connected so what I
suggest is when you take your dough out
of the refrigerator to bake it the next
morning always take the temperature of
your dough before you score it and bake
it because that will tell you if your
dough actually went to sleep and got
down here because I'm using this
model based
on the assumption that your dough
temperature will hit 39° fahit or 4° C
in the refrigerator if your refrigerator
doesn't get down to that temperature
these percentages will be too
high I made a video earlier this year
called post-pandemic sourdough for busy
people and in the latter half of that
video I talk about how to adjust and
calibrate all of these percentages your
percentage rise in bulk fermentation
your refrigerator temperature the amount
of time that's in the refrigerator if
you want to really dial this in I
recommend watching the second half of
that video the link is in the
description of this video and it will
tell you how to monitor and calibrate
all those
temperatures so I use that term
calibration because this is an essential
step in the process I wish that
sourdough baking were as simple as just
a piece of paper with eight numbers on
it it it's pretty close but it's not
foolproof so what you need to be able to
do is after you apply these criteria you
need to assess your Chrome and determine
if it's overproofed or underproofed so
you bake your loaf you cut it open you
look at the bsection of the loaf and
then you should consult the video I have
how to read a Sourdough crumb and
there's a guide that you can print out
and you're going to compare your loaf to
that guide and it will tell you does
your loaf look overproofed or
underproofed so let's say for example in
our scenario our 70° loaf at 75%
let's say that looks a little
underproofed if that's the case you want
to repeat that process exactly but I
suggest going up in 10% increments so
the next time you want your percent rise
to be 85% rise instead of 75% rise you
bake that loaf you cut it open you look
at it and you say oh my gosh 85% rise in
bulk fermentation my loaf is slightly
overproofed 75's under 85s
over wonder what would happen if we
tried an 80% rise so you make it a third
time at the 80% rise in bulk
fermentation it's perfectly fermented
perfectly proofed you make a note of
that on this sheet and say okay my
records now say at a 70° Fahrenheit
dough temperature I need to go to an 80%
rise it will repeat the same results
every time I mean once you dial that in
for a specific recipe it is repeatable
every time that's the beauty of this
method it takes the guesswork
out now for people who've been watching
my videos for years you might look at
this method and say wow this is really
interesting but this is a little
different than the method Tom
popularized back in 2020 which was
called the bul comatic system the
bulkmatic system is a technique where
you have nine criteria to determine when
bulk fermentation is done it's
specifically based on the tarene recipe
for that very warm temperature range
around 80° fah or 27° C D temperature so
there is one exception to this chart on
line number one if you're bulk
fermenting at 80° F 27° C that 30% rise
is a good approximation but you want to
augment this chart with the incredible
bomatic system nine criteria because the
dough is fermenting so quickly at that
dough temperature things can go south in
15 minutes I've seen it so you can't
rely entirely on the percentage rise
that'll get you in the ballpark but then
you need to ask the question is it domed
on top does it have bubbles on the side
does it wobble when you shake it what
does it smell like what does the window
pane feel like you need to use all your
senses and all your tools as a baker to
be able to bulk ferment dough at 80°
Fahrenheit or 27° C believe me that is
really expert level fermentation
territory when the dough is at that
temperature so for dough fermenting at
75° Fahrenheit or less all you need to
measure is the percentage rise and the
dough temperature if you're around 80°
or higher you want to augment that with
the bomatic
criteria so in today's example we just
fermented this dough at room temperature
we didn't try to control the temperature
and in our example 70° fah we did the
75% rise and as I've been saying the
whole time you want to ignore the timing
this is really just to show the possible
relative differences here because
everybody's starter is different but
let's say you do this process three or
four or five times and you keep really
good records of this and you're getting
perfectly fermented dough at 70° fah
with a 75% rise and the guidance here
says in my kitchen that would take about
12 hours with my starter let's say yours
takes 10 hours and it takes 10 hours
every time you do it this process
becomes incredibly predictable when you
repeat it like that and you'll find that
your fermentation times will be almost
exactly the same at those same
temperatures so then people start to ask
the question wow this is as predictable
as Clockwork what if I actually
manipulated my dough temperature then I
can make more sourdo because I can get
the timing to fit within my window so if
10 hours is a bad time slot for you to
work with between mixing the dough and
shaping the dough you could say what if
I sped that up to 75° fah to try to get
it to happen faster that's where people
use proofing Chambers so here's an
example this is the broad and Taylor
proofing box this is incredibly popular
it's a great tool this has a thermostat
on the side and you dial in what
temperature you want your dough
temperature to be at so let's say we
wanted to do it at 75 degrees Fahrenheit
I punch in
75° I put it in put my dough in here and
it'll maintain that temperature these
things work perfectly I also use this
for the tarene method where I'm bulk
fermenting at 80° fenhe or 27° C that's
way higher than my room temperature
would ever be so I bulk ferment my dough
in here because it ferments faster and I
want that timing I want a shorter time
window when I'm making that dough so
these warm proofers are great but
there's also something really cool which
is a warm and cold
proofer now if you've seen my videos
with Bob the sourdough for busy people
video or my post-pandemic sourdough for
busy people video I use this incubator
this can warm or cool your dough so
think about this once you get this
fermentation process down where you
literally can walk away from your dough
you all you look at is the percentage
rise now you can focus on controlling
timing where you can make your dough
work around your schedule so if 10 hours
isn't a good time window for you at 70°
fah 21°
C you could say I want to lower my dough
temperature to 65° Fahrenheit because
then I can stretch out the time you can
do that in here these are warmers and
coolers you basically mix your dough
after your stretch and folds you put
your dough in here you specify what
temperature you want your dough to be at
and you walk away these things work like
a clock I mean once you get this process
down if you set this at 65° fenhe and it
takes 12 hours it'll take 12 hours every
time I mean it's unbelievable because
when you control temperature you control
time and when you control time you can
make more sourdough bread because you
can fit it into your busy
schedule these are the future of
sourdough baking I'm telling you for
home Bakers
these warm and cold proofers give you
the ability to make dough on your
schedule if you're interested in that
concept watch my videos post-pandemic
sourdough for busy people or the
sourdough Brothers for busy people
thanks again for watching this video and
good luck on your sourdough
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Journey
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