Beer properties, meaning a good and strong beer for one type, may mean corruption and poor quality for the other. Here, strong hop aroma and light bitterness are a must in pilsner and IPA types, but inappropriate for Dortmunder type of beer. Dry sourness is the hallmark of the Berliner weisse and mature lambic, but in many other types of beer it would mean nothing else than beer gone sour. Lush malt fruitiness is very welcome for the English ale or barley vine beer, but not desirable for pilsner. For some types of beer, transparency is important, while others should have turbidity and cloudiness. Hereby, we will discuss only a few basic criteria that should be considered in purchasing beer.
By looking how carbonated bubbles behave in the glass of beer, you will understand whether beer was stored at the right temperature. If beer was overheated during storage, beer will produce high form because of very aggressive effervescence. And if beer was stored in too cold conditions, bubbles will rise, but with great difficulty and little abundance, because of altered protein structure of beer.
Beer should be stored in a cool place, protected from direct light, and away from heat sources. Temperature for aging and storage is different. For most types of beer, the suitable temperature is about 10-12° C, but it is slightly different for some varieties of beer. Storage temperature should be equal to the beer serving temperature. Therefore, strong beers, such as barley wine, tripels, dark ales should be served at 12-15° C. Most of ales (bitter, IPA dobbelbock, lambic, stout etc.) can be served at the cellar temperature (10-12° C). Meanwhile, lighter beers such as lagers, pilsners, wheat beers can be chilled to 7-10° C. Most often stronger beers served warmer, while lighter beer is cooled more.
The glass for beer should be cold. It can be stored at room temperature, but too warm mug will warm up the beer. Too cold mug is also not good because some flavour and aroma of highly chilled beer may be reduced.
From the behaviour of bubbles in the mug you can even determine whether the beer was served to you in a clean glass – if it sticks to the walls, it probably means that the cup has a greasy film. Meanwhile, the smallest dirt residues may permanently harm the taste of beer.
Foreign odours and tastes
Breweries must maintain the necessary love temperatures, their systems must not come in contact with oxygen and, of course, everything has to be sterile. However, even under these requirements, beer can be ruined with reused and improperly stored beer yeast. Another possible source of infection are beer accessories. Bacteria trapped in the brewing process can produce foreign odours and tastes. We will mention only a few of these that need to be considered. All of these characteristics can be tolerated in small quantities, but if there is a lot of them, it is an indication that something is wrong.
You should be worried if you feel valerian, extreme acidity, sweetness and salinity. Other worrying scents include hydrogen sulphide, or paper, metallic smell. Diacetyl – natural substance occurring during fermentation. It is usually felt and described as a test of butter or toffee in the beer. Up to a certain level it is tolerated in some types of ales, but is not desirable in some beer types (e.g. lagers). Diacetyl dominance signals of poor brewing technique also can mean bacterial contamination. Dimethyl sulphide (DMS) is reminiscent of the taste of cooked vegetables (cabbage, corn). Like diacetyl in ales, dimethyl sulphides are common in light lagers. In other beer types DMS is the lack of taste and can be caused by poor brewing practices or bacterial infection. Esters are natural chemical compounds that provide fruity and spicy tastes and flavours for beer. They can remind bananas, pears, or apples. Although this important component of beer flavour is detected, without exception, in all types of beer, but at extremely high concentrations it is also considered as an undesirable smell.
Therefore, if you have suspicion about some taste or visual nuances, do not hesitate to ask for a different cup.