1, granular hops
Granular hops are pressed into short sticks with a diameter of 2 ~ 8 mm and a length of about 15mm, which increases the density, decreases the volume and decreases the specific surface area. When stored in inert gas, hops are not easy to oxidize.
Granular hops have the advantages of small size, difficult oxidation, convenient transportation, use control and storage. This is the most widely used form of hops in the world.
2. Hop extract
Hop extract is extracted by ether, petroleum ether and ethanol according to the principle of countercurrent distribution. Evaporate the juice of the screw press in vacuum to obtain the first-class extract. Introducing steam into the residue, recovering solvent, extracting water-soluble components such as polyphenols with boiling water, separating to obtain water extract, and vacuum evaporating and concentrating to obtain secondary extract juice. The primary extract juice and the secondary extract juice are mixed according to a certain proportion to obtain a standard hop extract.
Because there are trace organic solvent residues in the extract, CO2 supercritical extraction is usually used to obtain the extract.
25% ~ 30% of the world's hops production is processed into extracts. The main advantage of hops extract is that it improves the utilization rate of α -acid
3. Heterogeneous hops extract
Ordinary hops are heated in alkaline solution, treated in ethanol in the presence of Ca2+ and Mg2+ to isomerize α-acids, and then purified with solvents such as toluene, methanol and dichloromethane.
Hop products do not need to be added to the boiling pot, which simplifies the wort saccharification process.
4. Hop oil
It is extracted from liquid carbon dioxide and contains about 20% hops oil. Like hops, it only contains a very small amount of α-acids, tannins and polyphenols, and does not contain nitrite and other substances that are useless to beer. It only provides fresh hops aroma and can replace hops and fragrant flowers added for the third time. The addition amount is 2 ~ 4 kg/200 t wort. Long-term storage in the specified hop library.
Hop products are easy to store and transport, but beer brewed by hops is better and the relative cost is higher.