"Rather good" is the judgment of an expert taster of a bottle of beer dating from 1872. Drawn in the port of Halifax (Canada), this Alexander Keith bottle had kept a very low ph and a good alcohol level. This proves that in a stable environment, beer keeps well!
In fact, whether they are fresh and frothy or with invigorating terroir aromas, the flavors that flourish through a second fermentation in bottle owe nothing to chance, and everything to the art of conservation applied for each style of beer ... and for quality tasting.
Even the lightest beers require minimal preservation to allow their flavor to flourish. But they must be consumed soon after being sold because of their low alcohol content and, more importantly, sensitivity to light and heat. On the other hand, being pasteurized, they have been subjected to high heat (flash pasteurization at 80 ° C. for draft beer and pasteurization at 60 ° C. for bottles or cans), killing any residual germs. This "sets" the action of yeasts, preventing this type of beer to develop its taste. These are the only beers for which the “best before date” is to be respected.
Light and heat are enemies to all beers, which is why the bottles are usually dark, brown or green in color. To further prevent flavor alterations of some beers, opacity is achieved by thickening the glass, as seen with the Blanches.
You don’t need to conserve your beer in a cellar, but, like wine, it is best to keep most fermented beers at room temperature between 10°C and 15°C and in a vertical position, essential for encapsulated bottles to avoid oxidation as it prevents contact with the capsules (even if internally coated with a protective film). For beers that re-ferment in bottle, also called “live beers”, the standing position allows the yeast sediments to deposit at the bottom. Thanks to the addition of a little sugar or honey, or new yeast before tapping, the yeasts will keep feeding themselves in the bottle. It is a common process, especially for abbey beers which will develop complexity in proportion with the period of aging.
When it comes to corked beers, the lying position is ideal. Contact with the liquid will increase the tightness of the cork, and alcohol and natural preservatives (hops in particular) will continue to develop the beer almost indefinitely. The best example of this type of conservation is Gueuze, a beer with a "champagne-like" look, which can be kept in lying position for several years. The Oude (or "Old") Gueuze by Timmermans, was elected "World's best sour beer" after having already collected several national and international gold medals; proof that our brewers know how to age specialty beers.
Some beers, those that are sweeter with higher alcohol content, can be kept for up to 60 years- or even longer in some cases like the one found in Halifax! The very patient tasters will appreciate the effect that aging has on their beverage as the taste becomes "maderized", more fruity and evocative of port.
A well-preserved beer can be a delicacy provided a few simple principles are followed.
First, the glass must be chosen according to the type of beer, preferably stemmed in the case of strong beers, to avoid altering the taste by the heat of the hands. Then, for the same reasons, the glass must be impeccably clean, free of any residue, washed separately from other dishes, and thoroughly rinsed with cold water and wiped. When pouring the beer, it is necessary to proceed in such a way to allow the foam to protect the beverage against air oxidation. It is necessary to fill the glass in two steps, first inclining it until half filled, then raising the glass while distancing it from the neck of the bottle. Once the foam stabilizes, the rest of the bottle can be poured. There is an open debate amongst specialists as to the right shape of glass: one with a flared collar to release the sugars and alcohol or, on the contrary, curved in (like wine glasses) to better preserve the aromas.
The choice is yours!