steeping grains in 6 gallons of water cause tannins?

[moedogger]

so i just had someone tell me that steeping grains in more then one gallon of water will change the PH level of the water and cause off flavors in my beer from tannins? so is this true?

[BDawg]

Yes, that is correct.

if the water pH exceeds around 5.8 (with the grains in it), that is high enough to extract tannins and cause astringency.

Depending on your water, it is quite possible that the large volume of water compared to the small amount of grains didn't drop the pH low enough to get below tannin extraction levels.

It is better to steep in a smaller volume, such as 1 gallon per lb. Partial mash and AG typically go 1-2 quarts per lb. You don't need to go that low. 4 qts per lb is fine.
Pay attention to the temp, too. If you can steep at mash temps (150-158F), you'll have no problems, and it is good practice for if you want to step up to partial mashes for those beers where you MUST mash (such as Classic American Pilsner).

HTH-