Views: 23 Author: Kate Publish Time: 2021-01-29 Origin: Site
Beer foam is a complex and difficult to understand phenomenon. What is a bubble? Simply put, foam is the process by which a large amount of gas escapes from a relatively small amount of liquid. Foam does not occur spontaneously, but requires an external force such as shaking or pouring into the cup to cause the gas to escape, sometimes known as "bubbling". So, beer brewing equipment manufacturers talk about how to get better foaming effect?
The proteins produced by the malt are hydrophobic, which causes the proteins to move up into the foam and support the structure of the foam with the substances found in certain hops. Since proteins provide the supporting structure for the foam, malt with a high protein and dextrin content is helpful for the shape and durability of the foam. However, high concentrations of protein and dextrin interact with the tannins to produce nutrients that damage the microbe, which means less fermentable extract is left. So finding a balance is crucial.
Examples of malt that can increase foam include crystal malt and wheat malt. One theory is that dark malts can help create good foam stability because they contain high concentrations of melanoids, which are protein polymers made of sugars and amino acids.
The stability of the foam depends on the protein content of the wort. The stability of the beer foam is affected by any step that breaks down the protein breakdown during the saccharification process. For example, the typical resting temperature for proteins is 49-54 ° C, which is used to promote protein decomposition, resulting in cold turbidity and improved foam stability. However, protein rest should only be used for moderately germinated malt, or for fully germinated malt mixed with more than 25% of ungerminated grains (e.g., granola, wheat, oats), as this breaks down large proteins into smaller proteins and amino acids, thus reducing foam stability.
On the contrary, the production of whole malted malt is used to produce enzymes, and adding a step of protein stop will reduce foam persistence. In order to increase its durability, you should use a slightly higher saccharification temperature, controlled between 68-71 ℃, and avoid protein resting.
Hops also contribute to foam stability. The bitter substances in the hops can all help to keep the bubbles gathered. This hydrophobic substance helps foam formation. However, this effect does not happen immediately. When you pour beer, the foam is loose and moist, but it becomes firm within a few minutes and adheres to the wall of the cup. This is also called a "hanging cup". In other words, wait a while before drinking, the effect of foaming and hanging cups will be better!
In general, higher hops will provide better foam stability, but remember to keep the balance between malt and bitterness. The cup you choose also affects the formation and stability of the foam. Slender cups are a good choice because they minimize foam contact with surrounding air and reduce carbon dioxide spills. If you use an open glass, on the other hand, it will be in more contact with the air, allowing more carbon dioxide to escape. For example, many Bavarian wheat beers and pilsons use long, thin cups to keep the foam forming and stable.
Another obvious but overlooked detail is the beiku itself. The cup should be "as clear as beer". Follow proper cleaning procedures to avoid grease residue. These substances take up space on the surface of the wine and prevent the formation of bubbles. Gushing: Many veterans have experienced this, sometimes you just open a bottle of beer and gushing out. The phenomenon is caused by excessive sugar or microbial spoilage. So make sure you measure the amount of added sugar accurately and do it under clean and hygienic conditions, then you should be fine.
Temperature: A decrease in temperature will increase the viscosity of beer, and the increase in viscosity will prevent the foam from disappearing, so the appropriate refrigeration temperature will bring better froth effect.
Finally, summarize the above points:
Get your carbonation right.
Choose malts with high protein levels (e.g. crystal malts, dark malts).
Avoid low-protein adjuncts (e.g. corn, rice, sugar).
Wheat malts and flaked barley will increase head retention.
Bittering hops help with head formation.
Sanitize and rinse your equipment well.
Depending on the grain, mash at high enough temperatures.
Nitrogen- CO2 gas mix can help with foam stability.
Avoid fats and oils.
Make sure glassware is beer clean.
Carefully measure priming sugar.
Serve beer chilled.
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