Hi everyone, Jennifer here
In the last 3 Dough 101 episodes
I showed you cold, warm, and hot water dough
In this one, I'll show how to use yeast to rise dough
In Asia cooking, we use it to make buns of various kind
In western cooking, it's used for bread making
With slight differences
Traditionally sour dough was used as source of yeast
But now we can just buy dry yeast
Much easier to deal with ... phew
There are 2 types: Active & Instant
Active need proofing before use
"Proof" is adding water & sugar to wake yeast up
Instant can be used "Instantly" :)
By the way, yeast is a fungus
that asleep in packaging .... zzzZZZ
It uses sugar and oxygen as food
and produces Carbon Dioxide which fills dough and make it rise.
but the dough need to have enough glutin or it will leak
When you remove water from yeast, will go to sleep
Here I'm using Insta yeast to make it easier
So I can add directly to flour and do an experiment
I will have yeast with sugar/no sugar, different temperature, covered/not covered as variables
To see which rises the best
I will add 1g of sugar & 1g of yeast to all cups
except for this column
In some recipes, salt is added
I'll add some to this cup to see what happens
For water temperature, at over 50c (120f), yeast dies
So I'll use slightly below 50c for the 1st row
For the middle row I will use 28c (~82f)
The optimum temperature for yeast
For the right most cup, let's cover for less oxygen
For the last row, let's pretend it's cold
and fill with 10c water (50f)
It's clear the column with no sugar isn't rising
For the rest, the highe temperature rises the fastest
At 50c, the yeast works really hard and takes the lead
At 20-30 min, the 28c mix is rising evenly and smoothly
At 40-50 min, the 10c mix finally rises
It looks like 50c is better because it's faster
But if you can smell it you'll see that
28c mix has the right smell (and implies taste)
For the cup with salt, the top rose well
but the bottom is uneven and watery
If anyone knows the reason, please leave a comment
This is cut without sugar (didn't rise)
For the one that was covered
At around 15 min you can see it was rising
After a few more minutes however
It deflated ... running out of oxygen
So you should cover the dough with cloth with rising
So it can breath
The next experimetn I'll play with amount of yeast
I'll need to add equal amount of sugar as well
I'll use 28c which we found works the best
We should be able to find out
what the best ratio of yeast to flour is
I'm using 1,3,5,7g of yeast with 250g of flour
and add equal amount of sugar
The add 150g of 28c water and mix evenly
Then add the yeast water to 250g of flour
Then knead into a ball
30 min later, the 1g bowl is still hard
and needs more time
The 3g bowl has risen some
The 5g bowl looks like it has risen
and has a wine aroma
Also has good pockets in the dough itself and looks done
The 7g bowl has a strong sour aroma
And texture is mushy
Obviously too much yeast
1 hour more later
The 1g bowl now has risen and have decent consistency
The interior has more pockets
and is malleable enough to handle
3g bowl has even better consistency
and is softer and more malleable
The 5g bowl's dough has large holes
and lost it's malleable texture so hard to handle
The 7g bowl looks like it has melted
So the best combo of texture, consistency, and smell
goes to the 3g of yeast bowl with 250g of flour
Which is about 1.2% of flour
Too little yeast, rising takes too long and dough becomes harder, drier
Too much yeast, the gas escapes before glutin forms
This happens when yeast is > 2% of flour weight
Even in the best case, it still felt a little off
How do we get more fluffiness out of the dough?
Let's now experiment with salt, oil, and length of kneading
Add 3g of sugar and 150g of 28c water
to 4 small bowls
Add 2g of salt to left 2 bowls
As we know from my Cold Water Dough video, salt will help glutin to form
Add 250g of flour to 4 large bowls
Add 3g of instant yeast
Add the small bowls of water to the 4 larger bowls of flour and yeast
mix evenly
Knead into a ball
Bottom right bowl doesn't have salt
I'm going to cover it with saran wrap so you can see inside
ordinarily I'd use cloth ... but the bowl shoudl be big enough
with enough air
Bottom left bowl has salt, I'm going to add some oil
Then cover with cloth to preserve moisture
Now we have 2 bowls left
left side with salt and right without that we are going to knead more
The one without salt is easy to knead
The one with salt has more moisture
and you need to knead in the bowl a bit first to absorb it
After about 5 minutes of kneading
Both dough is definitely bouncier
The one without salt feels like a slightly deflated ball
The one with salt felt like a mostly deflated ball
After continuing to knead for a total of 10 min each
Both dough texture improved (bouncier)
If you poke it, the dough is slightly sticky
and the shape rebounds nicely
The one without salt is still slightly bouncier than
the dough with salt
Cover these two and let's knead the one with one with salt & oil
With the oil, the dough is smooth and not sticky
easy to knead
10 minutes later, dough is really smooth
Let's cover it
1 hour later, let's see the difference
Bottom right had no salt and we only knead 1 min
With 3g of yeast, sugar and 28c water
The dough rose but has a very uneven consistency
contains a lot of small white clump (of flour)
If you pull on it, it has good amount of holes
but lack bounciness
Indicating there isn't not enough glutin
and no improvement over the last experiment
Now the top right bowl: 3g yeast, knead 10min
Same ingredients as the previous bowl but more kneading
The texture looks very different
The dough is very fluffy and white
Feels like cotton candy to touch
and bouncy
Pulling on the dough shows fine and evenly distributed holes
and stretchy texture
Success!
Let's see the top left bowl with salt and 10 min kneading
Same process as the successful one we just did
except has salt
It looks very similar to the last one
The surface looks slighly more smooth
But if you poke it, it feel much bouncier
Result of better formed glutin
Poking a hole you will see the dough is not as soft
and the sides retain their shape better
Pulling on the dough feels noticeably different
The dough is much easier to pick up
and feel much more "togetherness"
The holes in the dough are more fine and smaller
A result of better formed glutin
Keanding it again and it will become a very smooth ball
Overall very successful as well with a dough that is
stretchier, bouncier and less soft
Now less see the last bowl
with oil and salt, kneading 10 minutes
The dough immediatley looks the best
Very bouncy
Poking a hole, it is somehwere between the last 2
Softer than the last but bouncier than the one without salt
Handling the dough is also very easy
Everything is "together"
The holes in the dough are even finer than the last
Kneading it back to a ball, it becomes
Soft, smooth and bouncy at the same time
This is commonly used for bread making
Out of the 4, I like the #2 and #4
#2 is no salt or oil kneaded for 10 minutes
It the softest and best used for cake and Asian steamed bread (Man Tou)
#4 has oil+salt kneaded for 10 minutes
It is bouncy and stretchy while still soft
Can be used for many things
Last I'll summary how it works ... in technical terms
The 3 key factors
Starch + water + Amylase turns into malt sugar
malt sugar + water + Invertase turns into glucose
Additional sugar also turns into glucose
and is the jump start t to start the reaction for yeast
#2 Factor is when yeast starts to multiply consumnig glucose
Yeast consumes glucose and fructose + oxygen and breath
creating carbon dioxide, water, and heat
The carbon dioxide is trapped by glutinous structures
in the dough to "inflate" the dough causing it to rise
This process need oxygen
When lacking oxygen, yeast will produce CO2 and alcohol
#3 factor is how yeast multiply
If water exceeds 30c, Acetobacter (bacteria) will start to multiply as well
adding sourness to the dough
This is how sourdough is made
A successfully risen dough
Need yeast to multiply
to create CO2
and also depends on the ability for dough
to successfuly trap CO2 evenly
If you saw my Cold Water Dough espiode
You will know the importance of kneading
to even out the dough and help glutin form
which in turn can better trap the CO2
making the dough "fluffy"