Hello everyone, I'm Xiao Gao Jie.
Let's see how to ferment dough.
I usually use dry yeast.
Another common yeast on the market is instant yeast.
Instant yeast particles are generally considered to be smaller than dry active yeast particles.
But look at my dry yeast, it ’s not really big.
Many dry yeasts are made smaller than before these days.
Whether it's dry yeast or instant yeast,
dissolve it with water first, It will produce better fermentation results.
An experiment.
The first is to add yeast to the flour and then add water.
The second is that the yeast is dissolved with water before adding flour.
Same recipe, only changed the order of adding yeast.
The dough on the right produced better result,
since both yeast and flour need water.
Let the yeast absorb enough water first, it can mix in the dough faster and more evenly.
This is especially true for the dough with less water content.
After mixing, the dough begins to ferment.
At this time, there are two changes happening inside.
1. Amylase breaks down starch to sugar.
The second is that yeasts grow and reproduce in an anaerobic environment,
consuming sugars and producing carbon dioxide and alcohol.
Alcohol evaporates during heating and baking,
While carbon dioxide bubbles turn the dough into a soft sponge structure.
The most important factor affecting yeast growth and reproduction is temperature.
At 36 degrees Celsius, which is near human body temperature, yeast reaches the maximum activity.
However the speed of fermentation should not be our goal,
the taste and texture are the more important.
Between 20-30 degrees Celsius, yeast growth and reproduction slow down
24-26 degrees Celsius is the optimum range for dough fermentation.
Above 40 degrees Celsius yeast begins to die off.
Yeast is completely killed off above 60 degrees Celsius.
Below 10 degrees Celsius, yeast stops growing.
But sometimes you see the dough leave in the refrigerator for low temperature fermentation.
E.g Baguette
At low temperatures, there is no yeast activity.
However, amylase still converts starch into sugar.
Although it's slow.
But given long enough time.
The sugar produced from starch allows you to taste the sweetness of wheat.
Modern fast-fermented bread makes up for its flavour by adding sugar, fat, eggs or milk.
This kind of bread ferments quickly and usually has two periods of fermentation.
Let's take a look at the effect of these two fermentations and the impact on the finished products.
After mixing kneading, it begins the first fermentation.
When is it ready? Normally double in size.
The first fermentation requires yeast to multiply enough to ensure the second fermentation.
Poke a hole with your finger in the middle.
No retraction or bounce, the first fermentation is finished.
Degas, shape, put it in baking pan.
Now it starts the second fermentation.
Let it produce carbon dioxide again to form the final bread structure.
Final proof until 80 or 90% full. You can bake it at this time, and you will have a good bread.
But let ’s continue the fermentation and see what will happen to the bread.
The air pockets are too big, and cause the gluten to collapse in the oven..
Slice it open to see the structure inside.
It was all good until the last step.
Waste all our previous efforts.
The final proof before entering the oven determines the bread structure.
On the another hand, let ’s take a look at the effect of the first fermentation on bread.
After mixing, continue to ferment till 3-4 times larger. Poke a hole with your finger.
It collapsed.
Obviously it looks over fermented.
Continue to work on it.
You can smell the alcohol and a bit sour during the shaping.
Put it in a bread pan, final proof till 80-90% full.
Then bake it.
From the appearance, it puffs up.
The inside is fluffy and soft.
There are only very slight differences in taste.
Two doughs are the exactly same,
but fermented differently,
which made quite a difference to the structure.
The final proof/fermentation determines the structure of the bread,
Then the first fermentation process is used to adjust the flavor of the bread.
There is so much to talk about dough fermentation, I only mentioned a few.
Some are basic knowledge, others are from my own experiences.
I hope it can to help.
Thank you for watching. I'm Xiao Gao Jie. See you next time. ^^