First Experiment
First Experiment💦🍞-
The change in percentage hydration of dough to its final volume and texture of the whole wheat bread
Before Cooking-5Ws and How?
1.Who?🙆
This experiment is designed and conducted by myself mainly. This is to minimize the errors made during the experiment, like the strength of kneading.
2.Where?🏠
This experiment took place at the dining room of my home.
3.When?🕓
I did it at 22nd of March,2020 from 15:30-19:40.
4.What?
Ingredients:📒
Apparatus:🔧
And Oven!
5.Why? ❓
i) Why do i choose Whole Wheat Bread😏?
Nowadays, more and more people would prefer Whole Wheat Bread instead of the traditional bread made of white flour for health reasons. And the most common problem that people may encounter is about the hydration of the bread to its final texture, especially for whole wheat bread(as its flour absorbs more water than traditional flour). Therefore, i would like to choose whole wheat bread and how much liquid should be added to give different texture.
ii) Why do i investigate the effect of percentage hydration of dough💦?
Because the structure and texture of the bread is contributed by the hydrated gluten network. Therefore, the key to make the most ideal whole wheat bread is to find out the favorable gluten hydration condition in bread-making.
I want to find out the suitable percentage hydration of dough in order to home-make the whole wheat bread which is the most similar to the product on the market.
iii) Why do i choose height and texture as the dependent variables📝?
Firstly, the height of the bread is highly related to its gluten development. Also, it is almost the easiest variable to be measured in bread making. Therefore, the height of the bread is one of the significant variable to compare the gluten development of bread under different percentage hydration.
Moreover, it is actually not easy to quantify the texture of the bread. So i decided to further compare the fluffiness and softness by observing the bread,pressing on each sliced bread and tasting it. The bread will then be ranked from the hardest to the softest for more comparison.
6.How? ✔
i)Make the whole wheat bread in the same way but differ in the ratio of flour and liquid involved(including both water and honey) to adjust percentage hydration.
ii)Measure the height of the bread after taking out of the oven (after cooling for 5 min).
iii)Slice the bread after measuring the height into equal weight and observe the inner structure and texture of the bread.
iv)Compare and rank the inner structure and texture by pressing the sliced bread.
v)Find the one which is most similar to the reference one!
While Cooking☕
1.Weigh the dry ingredients(yeast,flour,salt) accurately using electronic balance and mix them well.
*The mass of each dry ingredient used is fixed and i would only adjust the liquid used to make changes in the percentage hydration of the dough.
2.Heat the water to 45°C.
3.Weigh and change the mass of water and honey used to adjust the percentage hydration of dough.
4.Mix the ingredients well and knead it the dough in to a ball
5.Transfer the dough into the container and cover it tightly to allow it ferment for 20 min.
6. Take the dough out after fermentation and then roll it in the bun-shaped.
7. Put the dough into the loaf pan and bake it for 40 min at 200°C.
8.Let the bread rest for 5 min and measure the height after resting.
9.Slice the bread into half. Observe the inner structure and press on the bread to test for its texture
After Cooking~
Results Presentation
Appearance of the bread
As seen in the first picture, the spiral shape of the bread becomes less and less obvious when the percentage hydration increases. It can also be explained by the second picture that the bread is denser when the percentage hydration increases. Therefore, it is more compressed when more water is added and so the spiral shape eventually disappeared.
Height of bread
60% hydration
|
70% hydration
|
|
Height of bread (cm)
|
5.5
|
~5.5
|
80%hydration
|
90%hydration
|
|
Height of bread (cm)
|
5.2
|
5
|
100%hydration
|
||
Height of bread (cm)
|
4.5
|
Height ranked from highest to shortest:
60%hydration ≥ 70%hydration > 80%hydration > 90%hydration > 100%hydration
*The height of the bread decreases with the percentage hydration.
Softness of bread
1.Compressing the bread
After slicing the bread, i used the same force to compress the bread. As shown in the above, the 60%hydration bread deformed the least while the 100%hydration bread deformed the most. There is also a trend that the bread deformed more when percentage hydration increases.
*The higher the percentage hydration, the easier the bread deformed.
2.Blind test
In order to further test its softness, i would also invite my family to taste the bread. And no surprisingly, the softness of the bread matches with the results in test 1.
Softness ranked from hardest to softest:
60%hydration ≥ 70%hydration > 80%hydration > 90%hydration > 100%hydration
Result Matches!
Moisture of bread
I tested the moisture of bread by touching the inner structure of the sliced bread. In order to get a more precise results, i also invited my family to conduct the same test. Almost all of us agreed that the 60%hydration bread is the driest one while the 100%hydration bread is the moistest one. The moisture of bread actually increases with the percentage hydration.
One funny result to be mentioned, some of my family find that 90%hydration bread has the same moisture content with the 100%hydration bread.
Moisture ranked from the driest to the most moist:
60%hydration ≥ 70%hydration > 80%hydration > 90%hydration > 100%hydration
*Special Case*
This is the dough of 50%hydration. We can clearly see that the ingredients cannot be fully compressed and combined together as it lacks water. No further kneading and baking can be conducted under this case. Therefore, i would delete the situation of 50%hydration in this experiment.
Data Analysis
As stated in the above, we can clearly see that both the softness and moisture of the bread increases with the percentage hydration. This implies that the percentage hydration of bread actually plays a really important role for the texture and structure of the bread. Because water is essential in gluten development. Not enough water, i.e. less than 60%hydration (example can be seen in the special case above), is not favorable for the gluten development.
However, if excess amount of water is added, the gluten development may also be inhibited. As shown in the data of height, we can see that about 60%-70% hydration gives the highest bread. And the height of the bread decreases eventually with the percentage hydration.
Choose the ideal percentage hydration!
After investigating the situation and conducting certain comparison, I find that both 90%hydration and 100%hydration bread have a similar structure and texture of the reference bread. If you are also a fan of the whole wheat bread on the market like me, i would suggest you to make yours with percentage hydration ranged from 90%-100% !
Source of errors and improvements
i)Room temperature
As the whole experiment has taken place for about 3 hours, the temperature may change within the experiment period. For further improvements, i would prefer inviting my family members to conduct the experiment with me to cut the time. Therefore, the variations in temperature will place only a little effect on the results.
ii)Ingredients left on table/flour roller
For the dough equal to or above 80% hydration, it is very difficult to knead after fermentation. Because the dough is very sticky and some of it may be stuck on the table or the flour roller. Also, i actually performed insufficient kneading for the dough equal to or above 80% hydration as the kneading time for the 60% and 70% hydration dough is much shorter. In order to keep the controlled variables be the same, i finally shortened the kneading time for the dough equal to or above 80% hydration. Next time, i would rearrange the order of making the bread,starting from 100% to 60%, to make sure there is sufficient kneading of all of the bread.
iii)Inaccurate size of baking mold
As the servings in this experiment are amended due to the instructions(only 4 servings in this experiment and the original is for 16 servings), the dough didn't fully fit the size of the mold. As a result, this would affect the size of the bread made. Therefore, i would prefer finding and using a smaller mold to fit the size of the dough to minimize the effect.
iv) Resting time
As to maintain the same fermentation time, I separated the baking process into 3 times, so that dough of two different percentage hydration can be baked at the same time. Each baking process takes 40 min, so the bread made first would take more time to rest and this may affect the moisture and texture of the bread.
In order to minimize the effect, I used lock bag to cover the bread baked first to minimize the water lost. Also, i would invite my family to conduct the experiment with me at the same time, so that all the dough can be fermented and baked at the same time. The result can be more precise accurate.
Reference:
Comments
Post a Comment