The functions of each part:

Inflation port: Connect to the air pump for inflation during acetic acid fermentation. Note: The lower end of the inflation tube should be inserted into the bottom of the bottle below the level of the fermentation liquid.

Exhaust port: used to discharge carbon dioxide during alcohol fermentation. The exhaust port should be connected to the bottle body through a long and curved hose. Its purpose is to prevent microbial contamination in the air. Note: The lower end of the exhaust pipe should be some distance away from the fermentation liquid level, the outside should be bent, and the pipe mouth should be kept downward as much as possible.

Discharge port: Take samples to detect the number of bacteria or the concentration of alcohol and acetic acid, and discharge waste materials.

Usage of the device:

When using this device for alcohol fermentation, the air inlet should be closed; when performing acetic acid fermentation, the air inlet should be connected to the air pump and oxygen should be introduced.

We need to know the source of the strain, the characteristics of the strain, the principle of fermentation, and the factors that affect its growth and reproduction.

The principle of making fruit wine

The source of yeast: the strains of natural fermentation are mainly wild-type yeasts attached to the grape skins; the strains of industrial fermentation are artificially inoculated Yeast.

Strain characteristics: Yeast is a single-celled eukaryote, a fungus, and its metabolic type is heterotrophic and facultative anaerobic.

The principle of making fruit vinegar

The source of acetic acid bacteria: artificially inoculated acetic acid bacteria.

Bacterial characteristics: Acetic acid bacteria are single-celled prokaryotes, bacteria, and their metabolic type is heterotrophic and aerobic.

Principle of fermentation:

(1) When oxygen and sugar sources are sufficient, acetic acid bacteria decompose the sugar in the grape juice into acetic acid:

(2 ) When there is a lack of sugar source, acetic acid bacteria change ethanol into acetaldehyde, and then acetaldehyde into acetic acid:

4. Factors affecting the growth and reproduction of acetic acid bacteria: temperature (the optimal growth temperature is 30 to 35°C), pH (living in an acidic environment), oxygen (acetic acid bacteria are particularly sensitive to oxygen content. When deep fermentation is carried out, even if the oxygen is interrupted for only a short time, it will cause the death of acetic acid bacteria. . )