Processing Methods and Technical Points for Schisandra Fruit Vinegar

Fruits contain abundant sugar resources and are superior raw materials for vinegar brewing. Compared with grain vinegar, fruit vinegar has richer nutritional components, being rich in acetic acid, succinic acid, malic acid, citric acid, various amino acids, vitamins and bioactive substances, with a mellow taste, rich flavor, fresh and refreshing character and unique effects, and can soften blood vessels and lower blood lipids. Fruit vinegar is acidic, but after being absorbed and metabolized by the human body it becomes an alkaline food. Fruit vinegar has the following health benefits:

(1) The volatile substances and amino acids in fruit vinegar stimulate the nerve centers of the brain and have the effect of developing intelligence. Medical research has found that the acid-base balance of the human brain is related to IQ; children with an alkaline brain have a higher IQ than children with an acidic one, and the acid-base balance of body fluids can be regulated through diet.

(2) Fruit vinegar can improve the liver's detoxification function, regulate body metabolism, enhance human immunity, and has a strong anti-cancer and cancer-preventing effect.

(3) The acidic substances in fruit vinegar can increase the secretion of digestive juices, thereby strengthening the stomach and promoting digestion, improving appetite, and promoting salivation and quenching thirst. Drinking fruit vinegar before and after drinking alcohol can accelerate the decomposition and metabolism of alcohol in the body, so fruit vinegar is highly effective at sobering up.

(4) Fruit vinegar has unique merits in beauty and skin care and has a regulating effect on the blood circulation system. Its mild acidity has a gentle stimulating effect on the skin, can balance the skin's dh, and can also control oil secretion.

(5) Fruit vinegar not only enables the smooth metabolism of carbohydrates and proteins in the body, but can also burn excess fat in the human body and prevent its accumulation. Long-term drinking has a weight-loss effect, inhibits and reduces the formation of lipid peroxides during the human aging process, and delays aging. It softens blood vessels, lowers blood pressure, beautifies the complexion, regulates the acid-base balance of body fluids, promotes sugar metabolism in the body, and decomposes lactic acid and pyruvic acid in muscles to relieve fatigue.

Processing Schisandra fruit vinegar includes three processing techniques: the fully solid-state fermentation method, the fully liquid-state fermentation method and the pre-liquid then solid fermentation method.

1. Fully solid-state fermentation of Schisandra fruit vinegar

(1) Process flow: Schisandra fruit berries -> remove rotten berries -> destem -> wash -> crush -> add a small amount of rice husk and yeast -> solid-state alcoholic fermentation -> add bran, rice husk and acetic acid bacteria -> solid-state acetic acid fermentation -> leach vinegar -> sterilize -> age -> finished product.

(2) Technical points:

Select fresh fruit with good ripeness and wash it clean with water. After crushing, weigh it, add bran at 3% of the raw material weight and vinegar starter at 5%, stir evenly, then pile it into a round or rectangular heap 1-1.5 m high, insert a thermometer, and cover the top with plastic film. Turn the material 1-2 times a day, check the material temperature 3 times, and keep the temperature at about 35°C. After 10 days the raw material gives off a vinegar aroma, the raw floury smell disappears, the material temperature drops, and fermentation stops.

The raw material that has completed fermentation is called vinegar mash. Pour the vinegar mash and an equal amount of water into a jar with a hole in the bottom (first plug the hole in the jar bottom with gauze) and soak for 4 hours before leaching the vinegar; the vinegar leached this time is called first vinegar. After the first vinegar has been leached, add cool water again; in general, for vinegar leaching the second vinegar is poured into freshly added vinegar mash for use in leaching the first vinegar. Fruit vinegar brewed by the solid fermentation method can be bottled after 1-2 months of aging. After bottling and sealing, it needs to be sterilized in hot water at about 70°C for 10-15 minutes.

2. Fully liquid-state fermentation of Schisandra fruit vinegar

(1) Process flow: Schisandra fruit berries -> remove rotten berries -> destem -> wash -> crush and press juice (remove pomace) -> crude fruit juice -> inoculate yeast -> liquid-state alcoholic fermentation -> add acetic acid bacteria -> liquid-state acetic acid fermentation -> filter -> sterilize -> age -> finished product.

(2) Technical points: Select fresh Schisandra fruit with good ripeness and wash it clean with water. First crush the washed Schisandra fruit with a crusher, then press and extract the juice with a screw juicer, and add 3%-5% yeast liquid to the fruit juice for alcoholic fermentation. During fermentation, stir 2-4 times a day, maintain the material temperature at about 30°C, and complete fermentation after 5-7 days. Note that the material temperature must not be lower than 16°C or higher than 35°C. Adjust the alcohol content of the above fermentation liquid to 7-8 degrees, place it in a wooden or enamel container, and inoculate with about 5% acetic acid bacteria liquid. Cover the container opening with gauze to prevent invasion by flies, vinegar eels and the like. The height of the fermentation liquid should be 1/2 the height of the container, and a grid plate should float on the liquid surface to prevent the bacterial film from sinking. During acetic acid fermentation, control the material temperature at 30-35°C, stir 1-2 times a day, and vinegarization is completed in about 10 days. Take out most of the fruit vinegar, and it can be eaten after disinfection. Leave the vinegar mash and a small amount of vinegar liquid, then add fruit wine to continue vinegarization.

3. Pre-liquid then solid fermentation of Schisandra fruit vinegar

(1) Process flow: Schisandra fruit berries -> destem -> wash -> crush -> adjust composition -> alcoholic fermentation -> spray acetic acid fermentation -> press vinegar liquid -> blend -> filter -> sterilize -> fill -> finished product.

(2) Technical points:

(1) Raw material treatment: Select fresh Schisandra fruit with good ripeness and wash it clean with water. Remove the fruit stems with a destemmer, and crush with a fruit and vegetable crusher; during crushing the seeds must not be crushed, and the juice must not come into contact with copper or iron.

(2) Composition adjustment: Mainly use white granulated sugar for blending, bringing the sugar content to 15%.

(3) Alcoholic fermentation: First add dry yeast at 89/6 to a sterilized 500 mL Erlenmeyer flask for activation, add 100 g Schisandra juice, at a temperature of 32-34°C for 4 hours; after activation, add it at 59/6 of the fruit juice to a wide-mouth bottle for scale-up culture for 8 hours at 30-32°C; after scale-up culture, add it at 10% to a 50 L yeast mother tank for culture at 30-32°C, with culture completed after 12 hours. Add the cultured yeast mother to the fermentation tank for fermentation, keeping the temperature at 28-30°C; after 4-7 days the pomace sinks, and when the sugar content of the mash juice is <=4 g/L the alcoholic fermentation is finished.

(4) Acetic acid fermentation: Inoculate acetic acid bacteria into a liquid medium composed of 1% yeast extract, 4% anhydrous ethanol and 0.1% glacial acetic acid, place it in a 500 mL Erlenmeyer flask with a liquid volume of 100 mL, culture for 36 hours at 30-34°C, then add it at 10% to an expanded liquid medium (the medium is composed of fruit mash that has undergone alcoholic fermentation), then add it at 10% to a yeast tank for culture. After the yeast matures, add it at 10% of the total volume of the fermentation mash for acetic acid fermentation. The fermentation tank should be provided with a false bottom, on which 5% rice husk and 1% bran by volume of the wine mash are first spread; after the wine mash is added, the pomace mixes with the rice husk and bran remaining on the wine mash, the wine liquid flows through the false bottom into the vinegar-holding bucket, and is then poured down from a spray pipe by a beverage pump, spraying for half an hour every 5 hours; after 5-7 days, check that the acidity no longer rises and stop spraying.

(5) Blending: Inspect the product and adjust the acidity to ensure a pure fruit vinegar flavor. First filter with a stainless steel mesh, then heat the fruit vinegar to 75-80°C and hold for 15 minutes.

4. Quality requirements for Schisandra fruit vinegar: The color is pomegranate red, with the unique aroma of Schisandra, a soft sour taste and sweetness, no off-flavors, no suspended matter or other impurities, no white film, and it is clear and transparent.