Hops, with its Latin name Humulus Lupulus, is a one-year cone-shaped flower from the marijuana family (sorry it does not contain THC) and grows in climbers and temperate climates. It is divided into male and female, and only female hops are used. These cones have yellow lupulin glands around their petals. They contain essential oil extracts and resins that enhance the taste of the beer.
Hop cultivation has been carried out for over 1000 years. It is known that the first use of hops was to get clean water and as a preservative due to its bitter taste. The first agricultural areas where hops are produced only for beer appear in Central Europe. In the early 16th century, this production spreads to Western Europe and the Great Kingdom. Towards the end of the century, a dozen varieties used in brewing began to be produced. Today, there are over a hundred varieties with different characteristics.
Hops are a natural preservative. They are added during or after fermentation so that the beer stays fresher and lasts longer.
Hops provide the aromatic balance in beer and are like a signature of most styles. The bitterness provided by the hops balances the sweetness from the malt sugars and gives the feeling of freshness in the beer you drink. The main bitterness element is in alpha acid resin, it begins to dissolve in water after it isomerized by boiling. The longer the boiling, the higher the isomerization percentage and the more bitterness the beer will get. But unfortunately, these oils, which contribute to the characteristic aroma and smell, are volatile. Most of them evaporate during the long boiling process. There are many types of hops, but they are generally classified into two categories: Bitterness and Aroma.
Aroma hops generally have fewer alpha acids. By about 5%, they give the beer that desired aroma and flavor more. Many hops varieties are in two streams and can be used for both purposes. Flavor hops are added towards the end of the boil and boiled for 15 minutes as standard.
Hot hops are added at the beginning of the boil and usually boiled for about an hour. If different types of hops are added at different times during the boiling period, a very complex hop profile can be created. That gives the beer a balance of bitterness, taste, and aroma.
Alpha acids are the main source of bitterness in beer. There are 3 alpha acids that give this bitter character: humulone, adhumulone, and cohumulone.
Hops should be boiled to reveal this bitterness. Thus, alpha acids will undergo a chemical change called isomerization and mix into the wort. During the ripening period of the beer, these alpha acids react with oxygen and lose their bitterness and mix with the odor and form a flavor that accompanies the beer.
Beta acids do not dissolve in the mash and do not cause bitterness until they react with oxygen. It consists of beta acids, lupulone, adlupulone, and colupulone acids. They differ from alpha acids due to their molecular structure. So, they do not become isomerized during the boiling process.
While alpha acids lose their bitterness during the maturation period, beta acids unleash their potential. Beta acids are harder and more permanent than alpha acids.
Although the oil extracts only contain 0.5-3% of the weight of the total hops. They are responsible for the formation of floral, spice, herb, citrus flavors. More than 300 molecular compounds that reveal different aromas in beer make the use of hops attractive. Three oil extracts stand out more than others: myrcene, farnesene, and humulene.
Myrcene brings out green, fresh, floral, and lemon flavors. It is necessary to apply the dry hopping method to reveal this taste.
Farnesene gives spicy, herbal, and floral flavors.
Humulene contains more spice flavors.