Aeration is the process of injecting oxygen into the wort while brewing beer, which is usually done after boiling when the wort has cooled down, however immediately after fermentation. This process quenches oxygen out of the wort solution which makes it difficult for the yeast to breed in its optimal amount hence leaving an incomplete fermentation process.
Hot side aeration refers to excess aeration of the wort, however there is a drawback to this process as oxidation while the wort is still burning hot can oxidize melanoidins present in the beer which gives a stale taste to your drink. Therefore, it is important that the wort cools down to room temperature before aeration. (Oxidation is the addition of oxygen, ie adding heat).
There are 3 primary methods for aerating wort:
- Splashing is a feasible method for aerating wort that adds some level of oxygen in the wort, however the addition of oxygen will not be as high as injection.
- Agitation is carried out by stirring vigorously with a spoon or whisking it with a whisk. This procedure adds comparatively more oxygen than splashing which must be carried out for a few minutes before adding yeast.
- Injection an aquarium pump with an internal sterile filter can help oxidize wort. Using a carbonation stone or aeration stone at the end of the filter will assist in spreading the air evenly. The filter must be clean and sterile as presence of germs will hamper the taste of your beer.
Apart from choosing from the above methods, one can opt for aquarium pump, carbonization stone and filter that will cost lesser than $25 and attain the best taste and fermenting process for home-brewed beer. Most importantly, one must use an appropriate sized yeast starter, without which there won’t be adequate level of yeast production with stale flavor.