1. Selection and treatment of apple raw materials: select the ones with high maturity.

cider

cider

Crispy apples should be free from pests, mildew and green, then washed with drinking water and drained.

2. Crushing to get juice: soak the apple in 2% potassium permanganate solution for 2min, then take it out, clean it and peel it. 6% ~ 8% sodium sulfite is added during crushing, and the uniformity of addition should be paid attention to.

3. Clarification and separation: The freshly squeezed juice is very turbid, so pectinase and SO2 need to be added in time, and then it is allowed to stand for 24-48h before fermentation. Because there are many sediments and the structure is loose, it is advisable to adopt the siphon method of moving down the straw step by step to obtain clear juice.

4. Adding pectinase: add 40 ~ 60 mg/L pectinase to the freshly squeezed apple juice, treat it at 30℃ for 8 hours, then squeeze the juice, and then treat it with 50mg/L pectinase at 30℃ for 4 hours to get clear juice.

5. Adjust sugar content and acidity: The higher the sugar content of fruit, the better. Generally, the sugar content is 5% ~ 23%, and the juice should be prepared before fermentation. If the sugar content is insufficient, add sugar to supplement, 1.7g sugar produces 1% alcohol. Organic acids can promote yeast reproduction and inhibit the growth of spoilage bacteria, increase the aroma of fruit wine and give it bright color. However, excessive fermentation not only affects the normal fermentation, but also makes the wine go bad. Before fermentation, the acidity should be properly adjusted, generally about 0.8 ~100 ml/.0g.

(2) Expanded culture of yeast

Primary culture: take fresh apple juice, put it in two sterilized test tubes, each with 10 ~ 20ml, and add cotton plugs. Sterilize at 0.06 ~ 0. 10 MPa for 30min, cool to room temperature, inoculate pure yeast 1 ~ 2 needles, shake well, and culture at 25 ~ 28℃ for 24 ~ 48h to make the fermentation vigorous.

Secondary culture: use sterilized triangular bottle (1000ml), fill 500ml of fresh fruit juice, sterilize as above, inoculate two test-tube yeast solutions, vigorously culture at 25 ~ 28℃ for 24 ~ 28h hours, and use after the violent fermentation period.

Tertiary culture: use sterilized Descartes jar or 10000 ~ 20000ml glass bottle, with fresh juice accounting for 70% of the volume, and the sterilization method is the same as before. Or add 150ml sulfur dioxide to one liter of fruit juice for sterilization, and then inoculate yeast after standing for one day, that is, inoculate strains in the secondary culture, and culture at 25-28℃ for 24-48h to make the fermentation vigorous, which can be used for further expansion, or transferred to a fermentation tank or a fermentation pool for fermentation.

(3) Fermentation management

Main fermentation stage: alcohol fermentation stage, lasting 24 ~ 48 hours. During this period, the temperature should be controlled at 25 ~ 30℃, and ventilation should be paid attention to to promote the propagation of yeast.

Main fermentation period: alcohol fermentation period, lasting 4 ~ 7 days. When the alcohol accumulation is close to the highest, the product temperature gradually approaches room temperature, the carbon dioxide bubbles decrease, and the juice becomes clear, that is, the main fermentation is over.

Squeezing outside the pool: After the main fermentation, the fruit wine is in a clear state. First, open the wine outlet pipe of the fermentation tank and let the wine flow out by itself. This is called pouring wine. The remaining dregs can be pressed by a press, which is called pressed wine.

Post-fermentation: the suitable temperature is about 20℃ and the time is about one month. After the main fermentation is completed, the original wine still contains a small amount of sugar. Ventilate when changing containers, the yeast will be reactivated and continue to ferment, and the remaining sugar will be converted into alcohol.

(4) Post-treatment

1, clarification

Cider is a colloidal solution and a complex dispersion system with water as dispersant. Its main components are molecular water and alcohol molecules, and the rest are tannins, pigments, organic acids, protein, metal salts, polysaccharides and pectin. They exist in colloidal form (particle radius is 1 ~ 100 nm), which is an unstable colloidal solution. The purpose of gelatinization and clarification in cider processing is to remove the factors that cause the quality change of cider in some wines, so as to ensure the quality stability of cider in the future shelf life, especially the physical and chemical stability.

Step 2 disinfect

In the quality index of cider, its precipitation is an important problem that affects the shelf life. Among them, biological precipitation is the main form of precipitation. In view of biological sedimentation, we should strengthen the control of production process, kill (inhibit) miscellaneous bacteria in juice making, fermentation, aging, filtration and packaging, and strictly implement aseptic filling conditions to ensure the quality and safety of final products during shelf life. Pasteurization is the most effective and safest sterilization method. At the same time, it is easy to destroy the color, taste and nutritional components of fruit wine, so it is generally not used in the production of middle and high-grade fruit wine.

(5) Filling

The filtered cider should be filled in time, and a certain concentration of SO2 should be maintained during filling. Ascorbic acid and potassium sorbate should be added to apple liqueur to prevent secondary fermentation.

Yuen Tai Wong (1997) thinks that pasteurization (68 ~ 72℃, 35min or 85℃, 35min) can also be used before filling to reduce the possibility of secondary fermentation, and high temperature and short time treatment have little effect on wine flavor. Qiu Dongmei et al. (200 1, Suqian Distillery, Jiangsu Province) thought that the sterilization and filtration of wine before aseptic filling had the least impact on the flavor of cider. If necessary, according to the variety of the filled cider, it can be bottled and stored at 0℃~ 2C for 6~7 months. [2]

Other treatments

CaCl2 _ 2 _ 2 treatment 1 can significantly improve the clarity of juice, speed up the clarification of juice, increase the acidity of fermentation broth and reduce the pH value of fermentation broth. There is no significant effect on yeast alcohol fermentation. The cider brewed by CaCl2 _ 2 _ 2 treatment has high titratable acid, low residual sugar and low solid content. Pure taste, refreshing, elegant color and outstanding fruit fragrance. When the juice treatment time is less than 65438±0.2h, the appropriate dosage of CaCl2 _ 2 is 0.4g/L; When the processing time of fruit juice is18 for 22h, 0.3g/L CaCl2 can be added.

Adding vitamin C can increase the acidity of cider and decrease the pH value of cider. When the dosage of chroma vitamin C is above 1.0g/L, the growth and reproduction of yeast are inhibited. When 0.75g/L vitamin C was added in delayed fermentation, the sensory quality of cider was the best, with obvious apple flavor, pure taste and refreshing taste.

3. The addition of sulfur dioxide can inhibit the reproduction of microorganisms such as wild yeast in the early stage of fermentation, delay fermentation, and be beneficial to the early clarification of juice. The chromaticity of cider decreased, and with the increase of dosage, the chromaticity of cider decreased slightly When the dosage of sulfur dioxide is 80mg/L, the sensory quality of cider is the best, with a faint apple aroma and a pure and refreshing taste.