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Why brew in a closed fermenter?


Closed fermentation makes home brewing and winemaking more consistent and trouble free, especially taking into consideration the varied brewing conditions that most amateur brewers ferment in. 

Closed fermentation, (or bottom fermenting) is done with specially cultured yeast stains. These strains are used  predominantly by  major brew houses and wineries world wide.

One advantage of fermenting under airlock is a more controlled yeast multiplication resulting in a less yeasty, crisp, lager style of beer.  When fermentation is complete there is also the advantage that yeast quickly settles out to form a firm sediment.


Not only can bacteria attack your wine or beer from the surface of unclean equipment, but it can come in the form of wild yeast in the air itself.  This is particularly  the case in hot, humid climates.

All Bett-A-Brew and DrinkART beer packs are  supplied with  various complimentary strains of bottom fermenting yeast for your convenience to ensure trouble free brewing.


To safeguard your wine or beer from contamination from wild yeast, fermentation should take place under a protective seal and the airlock is designed for this purpose.  There are several designs available, but each works on the same principle and are half filled with water to create a seal.

During the process of fermentation, carbon dioxide gas is formed, therefore the water in the airlock allows the gas to escape without allowing air back into the fermenter.

The airlock must securely fit into either a rubber bung or grommit and the water in the lock must never be allowed to evaporate.

As the gas can be seen bubbling through the water in the airlock a guide to the process of fermentation can be gauged.  However, the airlock should never be used as an accurate indication that fermentation is complete, as air leaks around the lid of your fermenter can mislead you.  For accurate analysis that fermentation is complete the hydrometer should be used.