How to evaluate a beer professionally?

Sensory evaluation of beer is a science. beer evaluation terms are terms used to express the quality of beer in precise and refined sentences. These terms are easily understood by people due to their long-term use, and have the effect of being concise and comprehensive. Beer evaluation terms are just common terms used to describe various beer qualities, many of which are conceptual words or comparative adjectives. Evaluators should combine their own practice and feelings, and through memory and comparison, can describe appropriately.

According to the beer quality standard, the sensory indicators of beer have four aspects: appearance, color, foam, aroma and taste. Appearance and chroma are the appearance of the beer, whether the intuitive feeling makes people trust and like it; the foam is the crown of the beer, and the foam is good, which will make people think that the beer may be of high quality; the real quality is the aroma and quality of the beer. taste. In general, these four sensory indicators are complementary to each other.

1. Appearance 

The beer is required to be clear and transparent, without obvious suspended matter and sediment, and the turbidity should not exceed 1.0EBC units (within the shelf life). The former uses visual inspection, which is very intuitive; the latter is more accurately quantitatively expressed by instruments. The "no obvious..." here often becomes a point of contention due to different understandings.

The clarity and transparency of beer and the presence or absence of obvious sediment can give consumers the first impression, and it is an important appearance index reflecting the quality of beer.

The following factors affect the clarity of beer.

The first is the quality of the filtering effect of sake liquor;

The second is the basic characteristics of the fermentation liquid, the hot coagulation and cold coagulation are not completely removed, the yeast is not strong and autolyzed, and it is often difficult to filter and clarify;

The last is the stability of beer. Beer with poor biological and abiotic stability will experience turbidity and precipitation due to various factors.

2. Chromaticity/color 

The chromaticity of beer can be measured by EBC colorimeter. A good light beer should be pale yellow, with a "green head" and should not be reddish brown. Chroma is not only an important indicator of beer sensory quality, but also an important indicator of flavor changes during beer storage.

The pigments in beer mainly come from two aspects: one is the browning reaction in the production process: including Maillard reaction, caramelization reaction, oxidation reaction; the other is the polyphenol derivatives of malt and hops

3. Bubble/foam 

When the beer is poured into a clean cup, the foam should rise immediately, which is called the foaming performance of the beer.

The color of the foam should be white; the performance is delicate, like cream; the foam is long-lasting and falls slowly, which is called the foaming time. The beer standard stipulates that the foaming time of high-quality beer is more than 210s. The foam edge hangs on the cup. There should be foam attached, called the foam hanging cup.

4. Aroma and taste 

High-quality beer requires a coordinated aroma, obvious hop aroma, and a certain malt aroma, pure taste, refreshing, harmonious beer body, soft, and no smell.

The aroma and taste of beer depend on the balance between various flavor substances and aroma components left in the beer. The unique aroma of beer is not a specific component, but is expressed by many components. Therefore, in order to improve the aroma and taste level of beer, it is not only necessary to focus on a particular ingredient, but the result of coordination.

The aroma of beer includes hop aroma, malt aroma and aromatic substances generated by the metabolism of nitrogenous substances during fermentation. Hop aroma is a unique and clear floral aroma exhibited by the good dissolution and combination of hop oil substances in beer; malt aroma is a kind of own aroma produced by malt during roasting; fermented aromatic substances are esters. The main lipids in beer are ethyl acetate and isoamyl acetate.