CZ275894A3 - Method of a long-term storage of fermented must, particularly vine must - Google Patents

Abstract

This method of preserving fermenting juice is based on the fact that the juice is first separated from the crushed fruit, then it is put into a pressure container. After the air is displaced by the juice and/or carbon dioxide the container is closed so that it is gas tight and then it is stored with the fermentation process having started in the juice prior to its closing in the pressure container.

Description

The invention relates to a method for the long-term preservation of fermented must extracted from grapes or fruit without the use of chemical preservatives and / or heating.

BACKGROUND OF THE INVENTION

Methods for the long-term preservation of fruit states are known which consist of pastering fruit juice at temperatures above 80 ° C. This destroys microorganisms, especially yeasts, which would otherwise cause various microbiological processes, especially fermentation, leading to a change in the chemical composition and nutritional properties of the must. The disadvantage of preserving fruit juices by heating is, firstly, a change in the taste of the must and, secondly, its depletion of some biologically active substances.

A number of chemical agents are known which, when added to fruit juices, inhibit or destroy microorganisms. These are, for example, sulfur compounds, salicilic acid, formic acid and others. These substances, in order to enable long-term storage of must, also require dosages that are detrimental to the human body and adversely affect the taste of the must.

Grape must at the very beginning of the fermentation process is a popular drink in the wine regions. It contains a number of preservatives that are beneficial to the human body. It is normally only available during the grape harvesting period, as spontaneous fermentation of the aplicated yeasts in just a few hours will convert some of the sugar in the must to 3 to 5% by volume of ethanol. . This process can be slowed down by sub-cooling the must to temperatures close to zero, but not completely stopped. There is a known way to prepare fermented grape must for marketing even outside the harvest season. It consists in killing the fermentation process in the must with one of the chemical agents, and before being placed on the market, they are added to the must in excess of pure yeast cultures to restore the fermentation process. This process also has a negative effect on the quality and nutritional value of the must and is therefore used only to a limited extent.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a simple method of preserving must, especially grape, without the use of chemical agents, which would allow long-term storage of the must and its immediate removal from the market.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a method for the long-term preservation of must, in particular grape, by separating the must from crushed fruits first, then pouring the must into a pressure vessel which is sealed gas-tight after the air has been expelled from the must. carbon dioxide, and stored, allowing the fermentation process to begin in the must before closing it in the pressure vessel.

Preferably, the must is spun into a pressure vessel having a volume of 0.5 to 2 liters, leaving at least 5% of the vessel volume free of the must. The effect of the process according to the invention is enhanced if the containers are stored at a temperature ranging from 0 to 12 ° C after closing. In a particularly preferred embodiment of the method, the cider is turned into plastic bottles with a screw cap.

The invention makes use of the fact that the pressure of carbon dioxide that develops during fermentation inhibits the reproduction of yeast. E.g. Schmitthenner, F. reports in Wein, Rebe, 16, 1934, p. 199, that yeast reproduction stops when about 15 g of carbonic acid are dissolved in 1 liter of must. This represents a pressure of 7.85 MPa at 15 ° C, 6.32 MPa at 10 ° C and 4.81 MPa at 5 ° C. Carbon dioxide pressure slows down yeast activity for a long time and eliminates all aerobic micro-organisms that are very sensitive to elevated pressure, acetic bacteria, molds, etc. Useful lactic acid bacteria that break down malic acid are not destroyed even at a pressure of 0.81 MPa. pressure can degrade acids.

So far, this knowledge has been used rarely in the winery to regulate the rate of fermentation processes, ie to influence the rate of fermentation so as to ensure optimal wine quality. Essentially, this technology has been made possible by the increasing use of metal tanks as fermentation vessels. The application of this principle in small volumes to grape must in the early stage of the fermentation process has led to the surprising finding that must under carbon dioxide pressure stabilizes and retains its properties for up to one year.

The market exploitation of the invention is then subject to the availability of pressure plastic bottles which can withstand the pressure of carbon dioxide, have a screw cap and allow easy decompression before consumption of the must.

Examples of technical solution

Example 1

Must pressed from healthy dry-harvested grapes of the Múller Thrugau variety was bottled into plastic bottles of 1.5 liters in the last week of September, leaving 10% of the bottle volume unused. The bottles were placed in a room temperature of 18 ° C with loosened screw caps for 10 hours. After this time, carbon dioxide bubbles rising to the must level were clearly visible and carbon dioxide escaped around the caps. Then the caps were tightened and the bottles were placed in a cellar room at a constant temperature of 10 ° C. For one. year, samples were taken every 14 days. After decompression, one bottle was opened and the must's chemical and taste properties were checked. It was found that the chemical and taste properties remained almost unchanged, the sugar content in the must remained constant, the content of acids and flavorings gradually decreased, but by a maximum of 20% over the whole year.

When the bottle was decompressed and opened at room temperature, the fermentation process and the original characteristics of the fermented must were almost immediately restored. In this form, the must is intended for consumption. During the decompression of musts, it is very foaming, therefore it has proved advantageous to leave part of the bottle volume unfilled.

Example 2

The must pressed from grapes of the Grüner Veltliner variety was fermented in a 450 liter barrel to the optimum stage for consumption. It was then centrifuged into 1.5 L bottles and stored as in Example 1. The monitoring was performed as in Example 1 with similar results.

Example 3

After pressing 100 l of must according to Example 2, the remaining marc was poured into 50 l of water and 9 kg of sugar was added. After 24 hours of leaching, the must was pressed from the mixture. The procedure was the same as in Example 2.

The invention will find application in the food industry, allowing the market application of a popular drink with positive health effects regardless of the season of harvesting grapes or fruit.

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Claims (4)

Method for the long-term preservation of fermented must, in particular grape must, characterized in that the must is first separated from the crushed fruits, then the must is poured into a pressure vessel which is gastightly closed after air is expelled from the must and / or carbon dioxide and stored, leaving a fermentation process in the must before closing it in the pressure vessel. Method according to claim 1, characterized in that the must is spun into pressure vessels of 0.5 to 2 liters, leaving at least 5% of the volume of the vessel without the must. Method according to claim 1, characterized in that the containers are stored at a temperature of 0 to 15 ° C after closing. Method according to claim 1, characterized in that the must is turned into plastic bottles with screw caps.