Factors Affecting Beer Foam

When beer is poured into a glass, the liquor will produce white and delicate foam, which is shaped like a beautiful white flower, so it is often called "the flower of beer". Generally, the foam of beer will last for 2 to 4 minutes, and some beer foam will last for as long as 5 to 6 minutes. The foam of beer gives beer a unique symbol and is one of the main quality indicators of beer.

There are many processes in the beer brewing process that directly or indirectly affect the beer foam shape, foam performance and foam retention.

Effect of Raw Materials on Foam

1. The protein content in the original barley for malting is too low, not only the yeast nutrition is insufficient during the fermentation process, but also the foam of the beer may be poor.

2. During the germination process, if the malt is not properly controlled and dissolved excessively, the foam of the produced beer will become poor.

3. The isohumulones in hops are beneficial to the formation and stability of foam, so the selection and addition of hops will affect the foam of beer.

Effect of saccharification process on foam

1. The selection of malt quality index in the saccharification ingredients, the malt ratio is too low, and the addition of hops is small, which will affect the formation of beer foam.

2. Unreasonable saccharification process, such as inappropriate rest temperature and time of protein or inappropriate saccharification temperature and time, will affect the foam of beer.

3. The addition of hops in the boiling process of wort, the boiling state, and the boiling time also affect the foam of beer.

Effect of fermentation and storage on foam

1. The traditional fermentation equipment (pre-fermentation) is a fermentation tank with an open opening, and it is relatively shallow. Part of the foam will dry up on the wall of the equipment or be lost naturally, while the conical fermentation tank has a high liquid level, a small cross-section, and is under pressure. Fermentation, foam loss is small.

2. After boosting the fermentation pressure or during wine storage and later filling, if the fermentation tank leaks, loses pressure, or the temperature and pressure fluctuate in a large range during the wine storage period, on the one hand, due to the unstable air pressure in the tank, carbon dioxide will Gradually escape, on the other hand, the protein in the wine will continue to decompose or precipitate, which may cause poor foam performance of beer.

The impact of other aspects on foam

1. Improper process conditions and operation methods in the production process will cause the loss of active foam components and affect the foam performance of beer.

2. The equipment, pipelines, utensils (dishes), and materials for beer production are unclean or oily. If they come into contact with wort or beer, the foam performance of beer will be seriously affected.

3. The pipeline design and pump selection for transporting beer should try to ensure uniform flow rate, heat preservation and pressure maintenance of the transported liquor, otherwise it will also affect the foam performance of beer.

4. The container and wine glass filled with beer are not clean, have water and oil stains, etc. will also affect the foam shape of beer.