Characteristics of hops and hop products

Hops contain many substances, such as resins, essential oils, polyphenols, proteins and inorganic salts of amino acids. The most important components of hops in beer brewing are hop resins, hop oils and polyphenols, which give beer its characteristic bitterness, aroma and stability. Hops generally used in beer brewing include compressed hops and hop products. Hop products include hop powder, hop granules, hop extract, hop oil and enhanced granules, isomerized extract, etc.

 Compressed hops 

Compressed hops refer to hops with a complete flower-like shape with a packing density of 300~350kg/m³ after being picked and dried at low temperature for several hours. When in use, it needs to be manually broken or crushed at low temperature, and then added to the boiling wort according to the specified proportion and time.

Using compressed hops has the following advantages:

1 It is easy to use and can be stored for about a year under suitable low temperature and dry conditions;

2 After being dispersed in the wort, the flowers and leaves are suspended in the form of flowers or sheets, and they are turned up and down with the convection of the wort, which is conducive to the adsorption and precipitation of protein coagulation, and the tannins in the flowers can condense proteins.

Using compressed flowers has the following disadvantages:

1. The storage space (or area) of compressed hops is large, the packaging materials are many, and the transportation cost is high;

2. Using compressed hops, the dispersion of active ingredients and the leaching effect are relatively poor, and the utilization rate of hops is low, so the addition time should be earlier and the addition amount should be more;

3. When using compressed hops, filter equipment must be used. If the recovery of wort in hop lees is not strengthened, it will cause equipment blockage and wort loss.

4 Due to the unbalanced α-acid content of compressed hops (including problems in hops packaging, storage, and sampling), it is difficult to control the bitterness value of beer.

 Hop pollen 

The compressed hops are crushed at low temperature, and then packed in a plastic bag or nylon bag lined with aluminum foil. The bag can be filled with inert gas or CO2, and added in proportion and time when used. Hop powder has a substantially similar composition to the original compressed hops.

The use of hop pollen has the following characteristics:

1 Easy to store and easy to use. Under the condition of vacuuming and filling inert gas, the storage time of non-oxidative hops is longer than that of compressed hops, and the storage space of hops is smaller than that of compressed hops;

2. It is easy to disperse in the wort, and the utilization rate is 10%~25% higher than that of compressed hops, and no filter equipment is needed after the wort is boiled;

3 The composition of the crushed hop powder is relatively uniform, and the hop powder can be added according to the α-acid content to control the bitterness of the beer;

4 The adsorption and precipitation of protein coagulum is worse than that of compressed hops.

 Granular hops 

Under the conditions of low temperature and oxygen avoidance, the whole compressed hops are crushed into hop powder, and then extruded into short rod-shaped particles with a diameter of 2~8mm and a length of about 15mm, and then vacuumized or filled with inert gases such as nitrogen and carbon dioxide. .

Advantages and disadvantages of using granular hops

The composition is similar to that of hops, but there is no loss when adding, and the aroma-enhancing effect is better than that of hops crushed by ordinary grinders, and the addition amount is similar to that of hops.

In order to make better use of hops, sometimes granular hops are often made into fortified types, that is, hop extract or extracted α-acids and other active ingredients are mixed with hop powder in proportion and pressed into granules, so that the amount of hops in a unit number of hop granules The α-acid content was greatly increased to save the floor space required for hop storage and to control the addition effect more effectively.

 Hop Extract 

The general hop extract (α-acid extract) is a resin extract that uses an extractant to extract a large amount of α-acid in hops. It is a hop product with α-acid as the main component. Hop extract is generally sealed in a container and can be stored for a long time at low temperature. When adding, the extract is added according to the α-acid content and the planned bitterness value, but generally only 1~2 times, rather than 3~4 times.

Pros and cons of using hop extract:

1 The volume and quality of hop extract are greatly reduced compared with compressed hops, the quality is reduced by 80-90%, and the volume is reduced by about 95%, and they are all small packages, well sealed, not easy to oxidize, and easy to transport, store and use.

2. Excellent dispersion in wort, high hop utilization rate, no hop residue after wort boiling, no need for hop separation equipment, and no wort loss to hops.

3. The bitterness value of beer can be controlled more accurately according to the content of α-acid. At the same time, because the leaching component of hop extract is mainly α-acid, especially the liquid CO2 extract, even fat and wax are not leached out. Therefore, the use of extract has certain benefits for the soft, refreshing bitterness and even foam properties of beer.

4 Since the extract contains few tannins, it is not good for binding and coagulating proteins, and the extract itself is an ointment oily liquid, so it is quickly dispersed in the wort after adding, and has almost no effect of adsorbing and precipitating proteins.

5 Because the preparation cost of hop extract is higher, the use cost is higher than other hop products. In addition, solvent-extracted extracts will have residual organic solvents. Although the wort boiling process will further remove these residual solvents, trace amounts of organic solvents dissolved or combined with other components will affect the taste or foam of the beer. Water-soluble isomerized extract (also known as iso-α-acid extract), because of its good solubility in water and the formed bitterness value, it can be directly added to the wine storage tank, or before filtering the wine Adjust the bitterness value, can also be used alone.

 Hop oil 

The hop oil component in hops, when the wort is boiled, most of it evaporates and escapes with the wort boiling, and some of it escapes with carbon dioxide during fermentation. In order to retain some aroma components, the hop oil is made into a distillate under vacuum and a low temperature of about 20 degrees Celsius in advance, and added during the final wine storage or filtration. This distillate composition is basically the composition of the original hop oil.

Pros and cons of using hop oil:

1. Hop oil can be added at different stages of beer production, but it is not easy to dissolve and disperse at low temperature.

2 The hop oil is added directly to the beer, and the flavor is similar to that of dry hops.

3. Hop oil can give beer a stable and long-lasting hop aroma and delicate taste, and make beer have typical aroma and flavor characteristics.