How to improve the foam performance of beer?

1. Raw materials and auxiliary products

• Malt: It is best to use malt with a protein content of 9% to 12%. Its high-molecular protein can decompose products to facilitate foaming, but it will also increase the possibility of beer turbidity.

• Yeast: It is feasible to use yeast with short fresh-keeping time, fermentation capacity and vitality, and reduced generation.

• Brewing water: The higher the residual alkalinity of the water, the better the carbonate solidification effect, and the higher the pH value, the greater the impact on the bubbles. Most importantly, the content of metal ions in the water needs to be controlled, such as iron, nickel, and various other ions.

• Hops: Use fresh, high-quality hops to provide specific molybdenum, the most potent alpha-acid structure, and the lowest fatty acid content. Hops must be stored at low temperatures and under oxygen conditions to avoid alpha-acid oxidation and free fatty acid build-up.

• Auxiliary basic materials: rice, corn, barley, and wheat are commonly used. Among them, the content of wheat glycoprotein is relatively high. Adding some wheat or wheat flour as auxiliary products helps to improve the foaming efficiency of beer. Rice and cornstarch are made up of a certain amount of fat that breaks up beer foam.

2. Mashing process

Temperature has a big effect on protein breakdown. For well-dissolved malt, the mash tank can be produced at 52 to 55 °C for 30 to 40 minutes to increase the high molecular weight and form foamed proteins, gelatin and viscous substances.

The high concentration of saccharified mash, lower pH value and stable enzyme activity are beneficial to the decomposition of protein and obtain higher polymer nitrogen.

The lauter tank should filter the clear wort, the water temperature should be controlled at 75~76℃, and the pH value should be 5.8~6.0. Excessive cleaning is prohibited, otherwise a large amount of polyphenols and fatty acids will be produced into the wort, which will affect the beer foam.

When the wort is boiled, a certain amount of hops is added, and about 20ppm of isohumulones are extracted by cooking, which directly promotes the formation of foam. The longer the boiling time, the higher the yield of isohumulones, the slower the rate of agglomeration of nitrogen, the increased volatilization of sesame oil, and the poor properties of melanin-stabilized foam.

The wort should have sufficient clarification time before cooling in the whirlpool tank to promote the complete elimination of thermal condensation and ensure that the condensed fat is distributed in the fermentation broth and directly enters the beer, which will cause poor foaming of the beer.

Use the bottom pump mash, adjust the speed of the mixer, etc. to prevent oxidation of the mash and wort, maintain a specific amount of polyphenols, and help beer foam.