How To Prevent Contaminants From Spoiling Homemade Wine?

Wild yeasts and acetic bacteria are the two enemies of successful homemade wine making. The acetic bacteria converts alcohol into acetic acid thereby turning wine to vinegar is ever present in the air. Similarly, the yeasts and spores of fungi which turn wine insipid and flat or turn it sour are also in the air. When using fresh fruit and other ingredients from the garden or from the shops, the bacteria, yeasts and fungi are also present, but fret no more because they are easily destroyed so they do no harm.

The ingredients usually used in making wine are usually supplied in sealed containers so that they will not be contaminated by the causes of so-called spoilage. However, the water that you might be using contains harmful bacteria that can spoil the wine or possibly the wild yeast can cause 'undesirable' ferments and these ferments could give 'off' flavors such as sour flavors.

It is not usually known that the molds on cheese, half-empty pots of meat paste and jam are often yeasts growing there for it is the yeast floating about in the air that ruins the wines that you make. So, in order to beat these souring yeasts, you must keep the fermenting wines and finished wines covered closely. Treatment of such finished wines is covered under the heading 'storing' and it is important that you cover fermenting wines.

When the prepared yeasts have been added to the liquid, the top of the jar should be covered with a piece of polythene and this should be pressed down all around by hand and a strong string tied tightly around it. This will keep airborne diseases away from the wine. Also, a good idea is to use a fermentation lock.

If the whole idea in using fermentation locks is to keep airborne diseases from contaminating the wine, make sure that the bung and lock are airtight. If they are not, the gas leaking will prevent air from reaching the wine during the early stages, but as it slows down the outgoing stream of gas through the leakage holes wouldn't be strong enough for this and so the airborne diseases could easily reach the wine.

You should fit the lock carefully to the bung and jar, and also run a little sealing wax where the bungs enter the jar and where the lock enters the bung. Although this precaution isn't necessary, it's better to be safe than sorry. Lastly, remove one piece of the lock and bung and insert a new bung when fermentation has ended. This wine can now be put away to clear.