>.This is probably a dumb question but how does the water pH get low? Is it just part of tap water or something else?
The grains will lower Ph, especially darker grains. Acid Malt is sprayed with lactic acid and will also lower Ph.
Water salts can also lower Ph.
If you use distilled water, there is no buffering, and your Ph may drop more than you would like.
Originally Posted by Frodo
oh ok... any empirical evidence, or just boogeyman speak?
Frodo, just because you did something incorrectly, and didn't notice a problem, doesn't mean there were no off flavors such as astringency.
Maybe you don't detect them because of the style, that doesn't mean they aren't there. Or maybe you don't know what the off flavor tastes like.
The most important point is to keep the Ph low, so you don't want to steep in a large volume of water.
From what I have read, Ph is the main determinant in leaching, but temperature can increase the leaching. Without proof, steeping grains should be steeped, at less than 170, then removed, not boiled. There may be no problem if you do, but it's not helping you, and may leach some Tannins. RM-MN made a good comment, which I pasted below.
The danger is you are giving misinformation to others, and claiming Tannin extraction is a myth. If you believe this, conduct some experiments, and post your results. But until you have proof, don't tell others to follow a bad process.
"To save money I don't use Starsan, I urinate on my equipment, and have never had an infection. Infections are just boogeyman speak".
Would you take anecdotal evidence like that?
"Water treatments are BS, I use my tap water which is alkaline and has Chlorine and my beer tastes great". (maybe the person only brews stouts, and the beer isn't as good as they think, or as good as it could be)
As RM-MN said
>>As noted above, steeping at a high temperature doesn't by itself extract tannins. In fact, you can boil the grains without extracting tannins to any great extent. Where you extract the tannins is with too high of a pH and high temps. If your pH remains low, no tannins. If you keep the temperature low you get no tannins either. Most of the time the grains will be low pH and will prevent your steeping water from being too high in pH but if your water was very alkaline, you could have problems.