When we need to make dough quickly because of the weather, we need to use yeast powder. Eating yeast powder can make dough quickly. Steamed steamed bread is usually fluffy, and its taste and quality are better than those without yeast fermentation.
What is "yeast"? Yeast is a kind of "unicellular facultative anaerobic eukaryotic microorganism strain" and belongs to "potential starter". When yeast is used, it will produce yeast. Under suitable temperature and environmental humidity, yeast will multiply and dissolve cassava starch, digest and absorb sugar in dough as nutrition, and then produce more carbon dioxide to wake up dough. Compared with "baking powder", yeast is richer in nutrition, healthier in body and mind and higher in safety; But it takes a long time for simple yeast to wake up (related to fermentation temperature, usually more than 2 hours).
Used for "proofing dough", the functions of yeast in dough are as follows: first, yeast acts on dough, which can promote the formation of protein chain;
Secondly, in the process of fermentation, yeast will digest and absorb nutrients-"sugar in dough", and then produce carbon dioxide and alcohol, giving full play to its "fermentation" role;
Third, the dough will contain some oxygen molecules during the whole mixing process. After mixing, the dough has high ductility and low friction resistance. After the dough is loosened by yeast fermentation, it will merge with each other according to chemical action, thus improving the strength of water gluten.
Fourthly, yeast will produce a lot of "pollutants" in the fermentation process, which is beneficial to the formation of unique cake baking smell for bread and other foods.
Eating food containing yeast can cause stomach trouble? This is also a widely circulated view. Some people say: steamed bread and bread can't be eaten when they are just steamed (baked), otherwise they will get stomach trouble; Look at the reason, the key butcher knife points to "carbon dioxide produced after yeast fermentation".
As we all know, yeast, as a biological leavening agent, does produce carbon dioxide in the fermentation process of steamed bread and bread, but its fermentation and flatulence work ability itself will be harmed by many factors such as temperature, dough composition, pH value and so on. Take temperature as an example. If the temperature exceeds 60℃, yeast cannot survive, so there is no need to hope that yeast can ferment and flatulence.
Will "yeast" produce carcinogens during fermentation? Legend has it that "because of the existence of yeast, freshly steamed steamed bread and freshly baked bread contain carcinogens, so they can't be eaten." Some people say that yeast is related to "bread carcinogen", leaving aside the carcinogen "acrylamide" produced by Maillard reaction; Yeast itself is a microbial strain, and its role in the process of making bread depends on the process of sobering up. The temperature of toast is generally around 200C, but before this temperature, yeast has long been extinct, so it doesn't matter to put it bluntly.
It is also said that steamed bread will also produce carcinogens because of the existence of yeast. In fact, it's right to eat steamed bread while it's hot (food or healthy drinks above 65℃ are carcinogens themselves), but it has nothing to do with yeast. In other words, cakes such as steamed bread will produce carcinogens when they are hot, so carcinogens should also exist after cooling. Can we say that they will fade? Therefore, this basic theory is unfounded and acceptable. We must treat it scientifically and reasonably, and don't believe it.
The safety of yeast deserves respect: Take the fried dough sticks as an example, the traditional fried dough sticks will rely on "Gong Ming", but they are suspected because they contain "aluminum". Regular or large intake of aluminum is very easy to accumulate in human bones, which increases the risk of osteoporosis and even continues to cause dementia.
Some shops use "biological starter" instead of Gong Ming to make fried dough sticks. After yeast is added to dough, carbon dioxide can be produced according to its own basic metabolism, thus achieving the purpose of bulking; The fermentation principle of yeast is simple "fermentation", which is not easy to produce adverse reactions to human body and can also give some nutrition to the body; Usually, we will continue to add some baking soda together, and the overall bulking effect is still very good.
Generally speaking, yeast is a reliable chemical substance with many nutrients. It has been used for thousands of years and has precipitated practical functions. It is actually reliable when used in a suitable medium.