The method of making Grass from Sweet Potato

Gvass was originally a traditional fermented beverage of the Soviet Union, which is nutritious, foamy, sour and sweet. It not only has the fermented flavor of wheat milk and hops, but also contains a small amount of alcohol. It is suitable for men and women of all ages. In addition to using bread or dried bread as raw materials, sweet potato starch can also be used as raw materials for the production of gavas with low cost and certain economic benefits.

1. Technological process: sugar production from powder pulp-enzymatic hydrolysis-fermentation-filling-pasteurization-finished product

2. Key points of process operation:

Sugar production from ① powder: first, the sweet potato starch was made into a slurry with 75% water content and stirred continuously. Then the slurry was heated up. When the temperature of the slurry was 35-45 degrees Celsius, 1530 units of cytolytic enzymes were added to every 100 grams of sweet potato pulp and hydrolyzed for 30 minutes. Then add Pectinase and add 1530 units per 100 grams of sweet potato pulp for 30min at a temperature of 25035 degrees Celsius for 60 minutes. Then add α-amylase to liquefy for 10 minutes at 60-70 degrees Celsius, then add Glucoamylase and hydrolyze for 20 minutes at 40-50 degrees Celsius. At this time, the dextrin in the sweet potato powder is completely decomposed into sugar.

② enzymatic hydrolysis: the above-mentioned slurry treated by enzyme preparation is then added with proteolytic enzyme to decompose protein. Add 1520 units per 100 grams of slurry, keep it at 45-55 degrees Celsius for 15-25 minutes, then heat up to 95-100 degrees Celsius for 1-2 minutes, make various enzymes inactive and stop the enzyme reaction. Add boiling water at 1:4, boil for 60 minutes, then cool to 25 degrees Celsius and filter.

③ fermentation: the filtrate was inoculated with 2% Saccharomyces cerevisiae and Bacillus Dehmannii respectively and fermented at 26 degrees Celsius for 16 hours. At the end of fermentation, cool down to 6 degrees Celsius, filter to remove yeast.

④ filling: under the condition of low temperature, fill the fresh gas into the glass bottle, and then cover it with a capping machine.

⑤ pasteurization: in order to kill the growing living cells, make the bacteria no longer reproduce and ferment, and ensure that the amount of carbon dioxide is within the normal range, so as to improve the stability and safety of the product, pasteurization must be carried out on the fermented bottled Gavas. Put the bottled gas into the cement trough or iron plate trough, soak the bottle cap with water, raise the water temperature to 60-70 degrees Celsius, keep it warm for 30 minutes, take out and cool the finished product.