The earliest people discovered that as long as they placed ripe fruits, grains and even milk from livestock such as cattle and sheep in various containers such as warehouses, tree holes, bamboo tubes, pottery urns or wooden barrels, After leaving it for dozens of days or even months or years, you can get a variety of delicious wines. But people at that time only knew what it was, but they didn't know why. As for how the wine was formed, it is even more difficult to explain, and it is attributed to the work of God or gods. In the seventeenth century, Antonie van Leeuwenhoek (1632-1723) used the microscope he invented to discover the existence of tiny organisms in beer and wine. It was not until 1850 AD that Louis Pasteur (1822-1895) confirmed that the formation of beer and wine was mainly caused by the growth and metabolism of microorganisms such as yeast in the brewing raw materials.
Yeast is mainly found in fruits, harvesting equipment, fruit parts bitten by animals, and wine-making equipment. Take wine as an example. After grapes are harvested and stored in wooden barrels, the yeast in them can use various nutrients in the grapes, such as sugars, vitamins, proteins and fats, to grow. Yeast decomposes the sugar (glucose, fructose, sucrose) in grapes to produce ethanol, the main component of wine. It also produces various aroma substances during the fermentation process, such as higher alcohols, esters, fatty acids and other special substances. , forming wines with complex aromas and flavors.
Can the brewing of alcohol be accomplished solely by the action of yeast? The answer is sometimes no. Although the yeast used for brewing will use simple sugars, such as glucose, sucrose, maltose and lactose, to directly brew fruits into various fruit wines, if the raw materials are rice, wheat, sorghum and other grains, the sugars in them are When starchy polysaccharides are present, yeast has no place to play. At this time, the role of fungi (Fungus), such as Aspergillus, Rhizopus, and Mucor, is needed.
Molds can produce a variety of enzymes, such as amylase, protease, and cellulase, which can decompose macromolecular substances in raw materials, such as starch, protein, and the outer seed coat of raw materials, to produce simple Substances such as sugars, amino acids, and nucleic acids provide for the growth of yeast. Therefore, traditional wines in Asia, such as China's Shaoxing wine, sorghum wine and Japanese sake, are all grain wines produced by co-fermentation of molds and yeasts. This mixture of mold and yeast is called koji. Baiqu (also known as liquor medicine) that can be bought in traditional markets now is a type of distiller's yeast.
Other alcoholic drinks made from starchy raw materials include beer made from barley and vodka made from potatoes. Beer uses enzymes produced when wheat germinates to hydrolyze starch and other macromolecules, and yeasts are used to produce alcohol and other flavor substances. In the later stages of alcoholic fermentation or during maturation, lactic acid bacteria or film-forming yeasts will participate, producing more flavor substances such as lactic acid and various aroma substances such as aldehydes, alcohols and esters, etc., further providing the flavor of the wine. Various fermented wines such as wine, beer, sake and Shaoxing wine, etc.
Fermented wine can be distilled to produce distilled wine containing a high amount of ethanol (generally above 40% v/v, where 40% v/v represents the solute volume as a percentage of the total volume). , such as whiskey, brandy, sorghum wine and shochu, etc. In addition, by soaking different raw materials such as traditional Chinese medicine, fruits and herbs, in fermented wine or distilled wine, and then maturing for a period of time, reconstituted wine can be made, such as ginseng wine, acanthopanax bark, plum wine, longan wine, and lychee wine. Liquor and gin, etc.
The ingredients of wine are quite complex, including water, alcohols, esters, organic acids, polyphenols, sugars, sulfur-containing compounds, etc. With the different ingredients and contents, many different styles of wine are produced.
Factors that affect the ingredients in wine include the type of raw materials, climate, raw material cultivation methods, processing methods and strains used. How to make a good wine that people like? In China’s winemaking industry, there is a famous saying that has been passed down since ancient times: “Qu is the bone of wine, grain is the flesh of wine, and water is the blood of wine.
” This means that the bacterial strains, raw materials and water used in brewing are the three major factors that affect the quality of wine. Only with good bacterial strains, raw materials and water, coupled with excellent processing technology, can good wine be brewed.