Old flour refers to flour seeds, and the north is called flour screwdriver. It's a small dough left over from steaming steamed bread, because there are many yeasts in it, which will be used as a strain next time. This kind of steamed bread made of the last fermented flour is called old flour steamed bread. In contrast, steamed bread made directly from yeast (dry noodles and fresh noodles) can't be called "old noodles". Lactic acid bacteria often exist at the same time in the preservation process of old noodles, which will have a unique sour taste after a long time, so it is necessary to add edible alkali to neutralize its sour taste when steaming steamed bread with old noodles. Specific practice: 1. Mix flour: appropriate amount of flour, sprinkle a little yeast powder (the ratio with flour is about 100: 1), and mix flour and water evenly, being careful not to be too hard or too soft.

Water is particular: use cold water or warm water in summer (it is enough to feel a little hot); Use hot water in winter, never scald it, or the noodles will burn to death. And after reconciliation, put it in a hot place, on a hot kang or next to a heater in the north.

2。 Check whether it is good: after a period of time, you will find that there are even honeycomb holes in the dough, and no sour taste is the best state.

If you accidentally open it and it turns sour, you can treat it with a small amount of alkaline noodles in the process of kneading in the third step, which can greatly reduce this sour taste and achieve better results.

3。 Kneading: Knead the dough vigorously until the dough surface looks very smooth and feels very delicate, and then it can be made into square, conical or other shapes of steamed bread. Every time you steam steamed bread, you will leave some, as long as it doesn't go moldy. This is the old face!