Principles Of Fruit Wine Making

We need to know the source of the bacteria, the characteristics of the bacteria, the principle of fermentation, and the factors that affect their growth and reproduction. The production principle of fruit wine The source of yeast: the natural fermentation strains are mainly wild-type yeasts attached to the grape skin; the industrial fermentation strains are artificially inoculated yeasts. Strain characteristics: Yeast is a single-celled eukaryote, belonging to a fungus, and its metabolic type is heterotrophic and facultative anaerobic.

Fermentation principle: (1) Yeast undergoes aerobic respiration under aerobic respiration conditions, and multiplies in large quantities: (2) Yeast decomposes organic matter under anaerobic conditions to produce alcohol (alcohol fermentation): 4. It affects the growth and reproduction of yeast Factors: Mainly moisture, pH (yeasts live in an acidic environment), nutrients, oxygen, temperature (around 20 degree is most suitable for yeast propagation, and alcohol fermentation is generally controlled at 18 to 25 degree ). Note: In anoxic, acidic fermentation broth, yeast can grow and reproduce, but most other microorganisms are inhibited because they cannot adapt to this environment. The production principle of fruit vinegar The source of acetic acid bacteria: artificially inoculated acetic acid bacteria.

Strain characteristics: Acetobacter is a single-celled prokaryote, belonging to bacteria, and its metabolic type is heterotrophic aerobic type.

Fermentation principle: (1) When oxygen and sugar sources are sufficient, acetic acid bacteria decompose the sugar in grape juice into acetic acid: (2) When the sugar source is lacking, acetic acid bacteria change ethanol to acetaldehyde, and then acetaldehyde. Acetic acid: 4. Factors affecting the growth and reproduction of acetic acid bacteria: temperature (the optimum growth temperature is 30 to 35 degree ), pH (living in an acidic environment), oxygen (acetic acid bacteria are particularly sensitive to the content of oxygen, When the deep fermentation is carried out, even if the oxygen supply is interrupted for a short time, it will cause the death of acetic acid bacteria.)