1- What is wine vinegar?
Vinegar has been part of the human diet since ancient times, being a product traditionally used as a preservative to extend the useful life of various foods.
As a consequence of the development of other more efficient techniques for the preservation of food, today it is used mainly to provide or reinforce the acid taste of certain products (Pascual-Ochagavía et al ., 2013).
According to the Technical-Sanitary Regulation that determines the requirements for its preparation and commercialization (Royal Decree 661/2012), vinegar is
” The liquid suitable for human consumption resulting from the double alcoholic and acetic fermentation of products of agricultural origin “.
According to it, in the market we can find up to ten different names , including fruit or berry vinegars, cider vinegars, alcohol, cereals, malt and, of course, wine vinegar (Figure 1).
2- Properties and benefits of vinegar.
The properties of vinegar in humans … include the reduction of the effects of diabetes and the prevention of cardiovascular disease, antibacterial activity, reduction of blood pressure and antioxidant activity.
It is one of the most used natural cleaning products against limescale. Added to food kills bacteria.
It helps prevent oxidative stress in our cells, therefore controlling how quickly we age. The antioxidant content may make it useful in fighting cancer.
Vinegar can inactivate some digestive enzymes that break down carbohydrates into sugar. This gives the body more time to get the sugar out of your blood, preventing the levels from rising.
ACIDITY AND ACID REFLUX:
Helps improve digestion.
3- How to make wine vinegar? How to do it?
Basic fundamentals on the elaboration of the vinegar of wine.
Wine vinegar is the result of two successive fermentations carried out by the action of different groups of microorganisms:
The first of these ( alcoholic fermentation ) is carried out by yeasts (mainly by different species of the genus Saccharomyces ), which will carry out the transformation of the grape must into wine, through the fermentation of simple sugars into alcohol and carbon dioxide. .
In the second fermentation ( acetic fermentation ), the alcohol generated is degraded by various types of acetic bacteria (of the genus Acetobacter ) to acetic acid, which determines the acidity of the vinegar (Vegas et al ., 2010).
Thus, although acetic bacteria are really feared in the winemaking environment due to their negative effect on wine, they are an essential element in the vinegar industry.
It should be noted that during both processes a great variety of secondary metabolites are generated that are responsible for the different sensory characteristics that the final product may have, modifying the quality of the vinegar produced.
4- How do you get vinegar? Methods of making wine vinegar.
There are two methods of making vinegar, the first and most industrialized is the submerged cultivation method and the traditional production method.
The submerged cultivation method , used in industry to quickly obtain lower quality vinegars, and the traditional method , in which acetic fermentation is carried out inside wooden barrels, which are filled with the liquid to ferment (Figure 2).
At the time of filling, a third of its total capacity is left free, in order to generate an air chamber that allows the growth and development of acetic bacteria on the surface of the liquid.
Consequently, a slow acidification of the product is generated , which means that long fermentation times are required to reach a suitable percentage of acetic acid, which increases the production time and the cost of the final product (Tesfaye et al., 2002) .
During this long process , the vinegar ages in contact with the wood of the barrel, giving rise to high quality vinegars highly appreciated for their greater organoleptic complexity.
It should be noted that in Spain there are three Protected Designations of Origin (PDO) that ensure good practices when making quality vinegars: “Vinagre de Jerez”, “Vinagre de Montilla-Moriles” and “Vinagre del Condado de Huelva” (Figure 3).
Among other functions, these PDOs establish the different categories of vinegars produced according to the aging periods to which they are subjected. As an example, within the PDO “Vinagre de Jerez” we will find three product names depending on their aging time: Vinagre de Jerez (with a minimum aging time of six months), Vinagre de Jerez Reserva (two years) and Vinegar de Jerez Gran Reserva (ten years).