Hops are an indispensable raw material for craft beer and are referred to by many in industry as "soul of beer". In craft brewing industry, brewers are especially careful about selection and use of hops. Today we will talk about what is so magical about hops that makes winemakers give it such importance!
First, role of hops
First of all, we need to understand what effect hops can have on beer. At first, people used hops in brewing mainly to increase antiseptic capacity of wort and beer, and later discovered that hops can also impart a refreshing bitterness and pleasant aroma to beer. In addition, iso-alpha acid in hops can increase head retention of beer; during co-boiling with wort, hop components can also promote coagulation and protein precipitation, which contributes to clarification of beer. wort and beer Non-biological stability. It can be seen that addition of hops during brewing process is of great importance.
Second, hop composition
How exactly does hops do these magical things? To answer this question, we need to talk about three main components of hops that are good for winemaking: hop resin, hop oil, and polyphenols.
Hop resin contains α-acid, which is main source of bitter components in beer, has a strong bitter taste and strong antiseptic properties, and can improve beer foam stability. The beta acid in hop resin is insoluble in water and easily oxidized, which also adds bitterness to beer.
The aroma of hops mainly comes from hop oil. Hops contain about 0.5-2% hop oil, and hop oil is very volatile, after a number of technological processes, about 90% of hop oil disappears. In craft beer, hops are usually added in stages so that an appropriate amount of hop oil remains in wort, making beer more hoppy.
Polyphenols make up 4%-10% in hops, and its main components are anthocyanins, tannins, catechins, etc. We know that when wort is boiling, it's time to add hops. The polyphenols in hops can help protein fall out sediment, which is useful for clarification of wort. At same time, polyphenols are also beneficial for abiotic stability of beer, making taste of beer full.
Third, hop classification
To facilitate transportation and storage, hops we use today are actually hop products, most common of which are hop pellets and hop extract. Among them, hop pellets are most widely used hop products, and yield is more than 50% of all hop products. According to different processing methods, they are divided into 90 types, 45 types, etc. Hops extract is a pasty liquid extracted from granulated hops using liquid supercritical carbon dioxide or water as a medium.
In terms of varieties, hops can be divided into bitter, aromatic and taste. Common high quality bitter hops include: domestic Qingdao Dahua, Nugget, Magnum, Golding, Chinook, Gelina, Hallador Bitterflower (Hallertauer). High-quality aroma hops include: Hersbruke, Hallertauer, Perle, Saazer, etc. Flavored hops are usually understood as some special hop varieties grown and planted in USA, Australia, Germany and other countries, such as Saphir, Galaxy, Citra, Aramis (Aramis ).
Although compared to brewing water and malt, amount of hops in craft beer is small, but its role is irreplaceable. Therefore, we still need to have some understanding and understanding of principle of operation, varieties and ways of using hops. In addition, we also need to pay attention to hop preservation method, generally applying low temperature (0-2 ℃), dry, dark, vacuum and oxygen isolation method. At same time, avoid joint storage with other odorous substances.