
one look:
Whether the surface is oily and shiny, whether there are impurities (just from hanging the pulp, the bean dregs for making yuba are sprinkled on the surface of the yuba), and whether the color is the beige of the bean skin (the color of the high-quality yuba is the beige of the bean skin). The 6.8 yuan yuba has a very white powdery substance on the surface, which is adulterated by pulping, and the surface is rough and dull. After breaking it apart, there are many small white spots in the middle, which is the added starch. The 8 pieces of yuba look bright in color, but the color that looks fake is not the normal yellow. The 13 yuan yuba seems to have a decent color, and the outside is very smooth. The 20 yuan yuba does not look very yellow in color, it has a light beige, and it feels very good and shiny.
Second break:
Good yuba is hard and easy to break, and the strips are broken with hollows, which look very translucent. The cross-section of the starch-added yuba has a lot of solids and a lot of white spots of starch.
Three smells:
High-quality yuba should have a fragrant bean fragrance, while poor-quality yuba has a peculiar smell, such as 6.8 pounds per pound, which has a salty and pungent smell. When you smell it, you know that it has been salted (sprinkle a layer on the surface of the yuba). salt for added weight).
Four tastes:
If your nose is not very effective, I suggest you break a piece and taste it. High-quality yuba has no peculiar smell, light taste, crisp taste, full bean fragrance, and aftertaste after chewing, while inferior yuba has a harder taste. It was chewy, had no aroma, and was soft and pasty, and a little salty (like salted).
Five iodine:
This is a killer. If you want to make a more obvious distinction, let's use our last weapon, a small bottle of iodine can do it. Iodine contains potassium iodide. If the yuba is mixed with a lot of starch, the potassium iodide will react with the starch to produce a blue mixture. That is to say, in this experiment, test the starch content in the yuba, soak it in iodine and see the change (The more starch, the darker the color), that's fine. The darker the color, the higher the starch content. After the experiment, we found that among these yuba, the cheapest color became black and blue. , while the most expensive did not change color.
Six bubble hair:
After soaking the yuba in room temperature water of 20-30 degrees for about 3 hours, at the same time, look at the state of the yuba, the quality of the yuba after hanging the residual pulp, the water will be cloudy after soaking, and the surface will be sticky; , the water is turbid and the appearance is rough; after the good quality yuba is soaked, the color of the water is clear, the strips are neat and shiny, and it is elastic and not brittle to the touch.