What is the difference between yeast steamed buns and old noodle steamed buns?

What works in old noodle steamed buns and yeast steamed buns is yeast. However, in addition to yeast, other fungi are also multiplying in the starter of old noodle steamed buns, which produces a sour taste and needs to be neutralized by adding alkali. Noodle yeast steamed buns use pure dry yeast, so there is no sour taste and no need to add alkali to neutralize it.

Alkali added to the steamed buns will destroy the B vitamins in the flour, so old noodle steamed buns are not as nutritious as yeast steamed buns.

During the fermentation process of old noodle steamed buns, other harmful fungi will produce toxic substances, some of which are even carcinogenic, such as aflatoxin. After the steamed buns are steamed, although the fungi can be killed, the The toxins produced will not disappear. Therefore, old noodle steamed buns are not as healthy as yeast steamed buns.

In terms of taste, steamed buns with old noodles usually have to be steamed before they are ready. Otherwise, fermentation will produce a sour taste, so secondary fermentation cannot be carried out, resulting in insufficient fermentation of the steamed buns. Steamed buns are generally firmer. It is what some people call "chewy". This kind of chewiness is okay for eating occasionally. However, if you eat it a few times, it will be difficult to swallow and you must eat it with soup. After the yeast steamed buns are made, they can be fermented a second time. The fermentation will be sufficient, and the steamed steamed buns will be soft and bubbly, with a very good taste. Moreover, it is very easy to make yeast steamed buns have the so-called "chewyness" of old-noodle steamed buns, that is, without secondary fermentation. The initiative is completely in the hands of the maker, while old-noodle steamed buns can only be made solid. It’s impossible to make it fluffy.

"Old noodles", also known as old starter, dough fertilizer, dough head, starter, etc., are made by letting the dough be placed in the air, allowing the wild yeast in the air to absorb and multiply, forming a mixture containing a certain amount of dough. The dry dough or semi-dry dough with yeast can be used as a starter to add to the new dough the next time it rises, allowing the yeast to resurrect, multiply, grow and ferment. Because "old noodles" are exposed to the air, they form a "breeding ground" for pathogenic bacteria such as mold and E. coli. These bacteria also multiply and grow in large numbers and secrete toxins, which are harmful to human health. Among them, aflatoxin B1 is very easy to cause liver cancer. Experts say that high-temperature cooking can kill harmful bacteria such as mold and E. coli, but it does not eliminate the toxins secreted by them. The toxins will be absorbed in the digestive tract and accumulated in the human body, which will cause cancer over time. Wei Fenglu, an expert at the Fermented Noodles Branch, said: Old noodle steamed buns have a different texture, which is actually the taste of edible alkali. Because the old noodle method usually makes the dough rancid and tastes sour, it is necessary to add edible alkali to neutralize the sourness. Therefore, the steamed buns have a strong alkali taste.

Vendors use old noodles as a gimmick to claim that their taste is different. In fact, they are exaggerating the alkaline taste of old noodles steamed buns. Over time, consumers have become accustomed to this kind of alkaline-flavored steamed buns. "But from a nutritional point of view, after adding alkali, the vitamins in the flour, especially VB2, are greatly damaged, which greatly reduces the nutritional value of the steamed buns." Wei Fenglu said. So, how to get safe, nutritious and healthy steamed buns? It is reported that the country promulgated the national standard for "Wheat Flour Steamed Buns" as early as 2007. "National Standard Steamed Buns" are products steamed with wheat flour and water as raw materials and yeast as the main starter. In addition, according to Kuang Jinbao, a well-known domestic yeast expert: Yeast is classified as a food attribute in my country's GB2760. It is not a food additive. Its classification number in the GB2760 food classification catalog is 16.04. Expert Kuang said: The dough is fermented by yeast, which not only adds nutrients to the steamed buns, but also decomposes the phytic acid in the flour and promotes the body's absorption of trace elements. Therefore, when people eat steamed buns, it is best to eat yeast-raised steamed buns, and do not be superstitious about "old-faced steamed buns".