1. Freezing method: It can be stored in a low-temperature refrigerator at about -20℃ to -30℃. This preservation method also includes the rapid freezing of dry ice alcohol and the preservation method of liquid nitrogen.
2. Carrier preservation: the microorganisms are adsorbed on some suitable carriers, such as some sand, soil and filter paper, and then dried and preserved.
3. Host preservation method: This can't be preserved by artificially cultured microorganisms. They are infected and transmitted through animals in our lives. This method is equivalent to the preservation method of general microbial passage.
Expanding knowledge: how to make yogurt with yogurt starter
1. The inner container and stirring spoon of yogurt machine were scalded with boiling water and disinfected.
2. Drain water, prepare 1000ml milk, take out a small bag of yogurt starter from the refrigerator, first pour a small amount of milk into the container, add bacteria powder and stir, then pour all the milk and stir evenly.
3. Then put it in a yogurt machine to ferment at a constant temperature of 42-45 degrees for 6-8 hours (or set the fermentation time according to the instructions of your yogurt machine), and then solidify.
4, put it in the refrigerator for a period of time, and then add your favorite jam and fruit to taste better.
How to choose yogurt starter
1, look at the fermenting bacteria.
The two basic fermentation bacteria of yogurt are Lactobacillus bulgaricus and Streptococcus thermophilus. These two kinds of bacteria are not resistant to gastric acid, so yogurt made with only these two kinds of bacteria has no conditioning effect. But with these two kinds of bacteria, you can make the most basic yogurt.
Step 2 look at the packaging
Some fermenting bacteria (such as Bifidobacterium) are anaerobic, so nitrogen should be filled in the package to protect the fermenting bacteria.
3, look at the dosage
Generally speaking, the ratio of yogurt starter to milk is between 1:500~ 1000, that is, 1g yogurt starter can ferment about 500g~ 1000g milk.
The above is what Bian Xiao shared today, and I hope it will help everyone.