Vinegar-Making in the Home

New Zealand Journal of Agriculture, Volume 60, Issue 1, 15 January 1940, Page 58

Vinegar-Making in the Home

Viticulture

V 7INEGAR is made from sugary VINEGAR is substances by alcoand starchy substances by alcoholic and subsequent acetic fermentation. In France vinegar is made almost exclusively from wines. In the United States of America cider-vinegar is in great favour. In the British Empire the use of malt vinegar predominates, although other vinegars are manufactured locally, as. for instance, in parts of Wales and in Monmouthshire, where : a quantity is made from perry, and crab-apple cider. The principles involved in the manufacture of these vinegars are, however, identical. . ’, Amateurs frequently find that the beer, cider, or wine they, have made has not turned out quite what they

expectedthe flavour is not quite right, or there may be already a start of acetic fermentation, which renders it unpalatable. It may still, however, be suitable for making vinegar. , For flavour and aroma, home-made vinegars from red and white wine, cider, perry, mead, and the fermented juice of fruits such as currants and gooseberries are far superior to commercial vinegars, which are ; made principally from grain, glucose, or sugar, with the addition of caramel for colouring and artificial flavourings.

Essential Component

The acetic acid, which is the essential component of vinegar, is trans-

formed from alcohol by a special ferment known technically as “Mycoderma aceti,” or, more, generally, as “mother of vinegar” or “vinegar plant.” which forms a greyish film of fine network on the surface of the liquid. It is necessary that this film should remain on the surface, as it requires air for its development and to aid it in oxidising, the alcohol. The Mycoderma aceti also requires a warm atmosphere in which to work, from 70 deg. to 90 deg. F. being the most favourable. Higher or lower temperatures retard its growth. To facilitate the process the barrel containing the alcoholic liquor may be placed

outside in the shade, or, in cool weather, inside near the stove.

Use of Barrel If it is not desired to use the barrel already containing the fermented liquid, or if its transformation therein is not practicable, a clean barrel which has contained vinegar, wine, or spirit may be used. It should be thoroughly scalded with steam or water beforehand, and then placed on its end and the top taken out and the open end covered with cheesecloth to keep out the vinegar-flies while the acetic fermentation is progressing; or,, for continuous use, a barrel laid on its side with the bung-hole uppermost is more convenient. -•?<’ y’ J;;, J*•; ’ *■}- ; -U A‘‘.‘'' This barrel should have two fin. or lin. holes bored in the upper part of the ends, and these should be covered with fly-proof muslin, mosquito-net, or wire mesh which has previously been varnished. With the aid of the bunghole, covered with similar material, a free circulation of air can thus be obtained. The hoops should be painted or varnished inside and outside to preserve them from the action of the acetic acid, which corrodes most metals, ; and a wooden tap placed 2in. or 3in. from the bottom of one of the ends. The barrel must be firmly fixed, so that the vinegar plant will not be disturbed by vibration. It is then 'partly filled with alcoholic liquid, leaving about one-third or one-fourth of the barrel empty to allow a free circulation of air over the surface of the liquid. T e sting To make a good vinegar containing 6 to 10 per cent, of acetic acid, the fruit juice, sugar, lor honey solution should contain before fermentation from 12 to 20 per cent, of saccharine matter, which, when fermented, will produce from 6 to 10- per cent, of pure alcohol, and, when transformed by acetic fermentation, from 6 to 10 per cent, of acetic acid. In a liquod which has already fermented the desired strength can be regulated by diluting the water or adding sugar or honey and refermenting. To test the saccharine contents of the original must or unfermented liquid a Baume hydrometer or a Brix or Balling ' saccharometer can be employed. Either of these can be pur-

chased for ss. to 6s. The degree Baume is equal to 2 per cent, of sugar in the liquid at 60 deg., and the Brix and Balling degrees are equal to 1 per cent. '> ■ ' ’ - • - If, on testing, the sugar contents are found to- be insufficient, 4oz. of canesugar or soz. of honey should be added for each additional degree of alcohol or acetic acid it is desired to obtain. These figures are not scientifically exact, but they are convenient to 1 work from and give results near enough for the purpose. , , . Right Ferment To ensure the introduction of the right ferment and the exclusion of the My coderma vini—which forms a thicker film, of a ' whiter appearance than. the Mycoderma aceti, and -transforms the alcohol into carbonic-acid gas and water —a small culture of vinegar bacteria or Mycoderma aceti may be developed in a shallow basin or saucer in a warm corner - from' an alcoholic liquor, such as wine or beer, mixed with a little vinegar, and the film, when formed, transferred carefully to the „ surface of the liquid in the barrel. The same result may be obtained by pouring 10 per cent, of vinegar from a previous brew into the contents of , the barrel. The alcoholic fermentation must be complete before the vinegar ferment is introduced, or the yeast ferment will be stopped by the acetic acid and unfermented sugar will remain in the vinegar. , . A strong alcoholic liquid is not so easily acidified as a . weaker liquid. Therefore, when making strong, vinegar it is advisable to start the barrel with a little fermented liquid of low strength (3 or 4 per cent.) and add the stronger liquid gradually. Time Required ', ■ Under favourable conditions a good vinegar will result in about three months. If it contains more than 10 per cent, of acetic acid this will act as' an antiseptic to unfavourable bacteria, but in vinegar of a lower strength when the alcohol falls below 1 per cent, the bacteria destroy the ethers and finally the acetic acid itself, which is oxidised to carbonic-acid gas and water, or undergoes what is known as putrid fermentation. To obtain a perfect vinegar I to 1| per cent, of alcohol should remain unconverted.

This increases the flavour of the vinegar when maturing in the barrel. The amateur who has no means' of ascertaining when this point is reached may arrest further development when in his judgment a full vinegar flavour had been obtained. If not already clear and bright, the ' vinegar may then be filtered through a flannel bag or clarified with isinglass, and then heated up to 130 deg. F. to ensure good keeping qualities by killing all bacteria, ferments, or vinegar-eels. It may now be run into 'a ■ clean barrel and stored for a year, which will greatly improve its flavour. The barrel should be kept tightly bunged and vinegar added from time to time to replace that which evaporates through the wood. Bottling If it is desired to bottle the vinegar at once it should be allowed to cool before doing so. or, better still, it may be run into bottles cold and pasteurised at 130 deg. F. in the bottles. A convenient method for withdrawing the vinegar from the cask when no tap has been inserted is to siphon it off through a small rubber tube attached to the lower end of a stick, so that its lower end will be well above the lees, which should not be disturbed. The stick is then let down into the barrel, and the vinegar siphoned off into the bottles. ' , , In the continuous barrel process about , one-third of the vinegar may be drawn from the barrel and the same’ quantity of fermented liquid added through a glass funnel with a long spout so as not to rupture or precipitate the Mycoderma aceti film. This operation 'can be repeated whenever the vinegar is ready to draw. Clarifying To clarify .vinegar which is not clear and bright the v substance giving the best results is isinglass, employed at the rate of loz. per 100 gallons of vinegar, broken up into small pieces, and each ounce soaked in a gallon. of warm vinegar until it swells up and becomes soft. It should then be passed through a hair sieve and any lumps that are retained broken up. The solution should be of a perfectly smooth consistency before being used. In this condition it can be added to the bulk of the vinegar, thoroughly 1 mixed by stirring with a suitable piece of wood, and allowed to stand about

a week to permit the isinglass to settle to the bottom, dragging down with it the substances which were the cause of the cloudy appearance in the vinegar. The clear vinegar can then be siphoned or drawn off through the tap. . ■ 1 . t - ,

In order to avoid the introduction Vi of the Mycoderma aceti into honey or by weak alcoholic liquors such as beer, w hii cider mead, or wine, vinegar should /. not be manufactured in or near buildings in which these are handled or stored.

'inegar is manufactured wholesale the quick, or German, method, ich requires a considerable plant.

J. C. WOODFIN,

Vine and Wine

Instructor, Te Kauwhata.