Why is the PH important during the boiling process?

The pH value affects your beer in many ways, so it is worth paying attention to the pH value of the wort at several points throughout the brewing process. We are specifically studying the effect of pH during the boiling process.

One of the main reasons we try to control pH during the brewing process is to avoid excessive tannin extraction. Most of the tannin extraction occurs during the mash and spray process, mainly from grains, but hops also contain tannins.

Tannins are water-soluble compounds that can give your beer a strong astringency. In order to feel this effect, the dryness and astringency of the tea is reduced to the level of tannins. By weight, the plant matter of hops contains only about 2-5% of tannins, but can contribute up to 20% of tannins in the finished beer.

copper beer brewing equipment

So how to control this extraction? Well, there is practically nothing you can do except reduce the amount of hops used or reduce the plant matter in the boil. If you are a brewer who uses whole hops when boiling, you can consider using pellets to try to reduce tannin extraction.

Making the boiling pH correct (approximately 5.1) also helps to form thermally broken materials. Protein is a chain of amino acids, including amino acids that avoid water (hydrophobic) as much as possible. These amino acids face the protein, so they can react with each other instead of water, but as the protein solidifies, some of the hydrophobic amino acids will face outwards. In order to avoid moisture, these amino acids will combine with the hydrophobic amino acids of other coagulated proteins to form larger and heavier protein clumps, which will fall off the suspension while taking away tannins and hops.

As the boiling pH decreases, the hydrophobic parts of the proteins can react with each other more easily, which means they will clump faster and fall out of the suspension. The most effective pH for this is 4.9, which means that brewers can boil below the usual 5.2 – 5.4 pH to achieve more effective protein coagulation, but this will reduce the utilization of hops.

The solubility of hop isoacid depends on temperature and pH. Solubility increases with increasing pH, so with a higher boiling pH, you can actually make better use of hops and better bitterness extraction, although the bitterness extracted in a higher pH boiling is considered to be better than It is harsher in boiling at normal pH (5.2 – 5.4). During the fermentation process, the pH value of the beer will drop further, which will cause the unisomerized hop resin to separate out of the suspension.

Finally, the pH value during the boiling process has a great influence on the color of the beer. The higher the pH, the darker the wort becomes during boiling, because more melanoids are produced. If you want to make a lighter beer, then your pH should be a key consideration.

Finally, if your mash pH and spray pH are both within acceptable ranges (the mash is 5.2 – 5.4, and the spray is below 6.0 when running), then your boiling pH should also fall within an acceptable level Inside. During the boiling process, the pH drops by approximately 0.1 – 0.2 units.

Do you measure pH throughout the brewing process or do you take it into consideration when planning your recipe? Please send an email to kate@degonget.com