Sparge water ph for Stout

[Rich819]

I had a question on the recommended ph of sparge water when brewing a stout. I dont need to adjust the alkalinity of my brewing water because the ph comes in perfect. The ph of my brewing water is around 7, usually when doing Ipa I get it down to 5.4 range with phosphoric acid. Should I adjust the water or leave it when sparging for a stout.

 

[ajdelange]

Whether or not you need to do so depends on the alkalinity of the water. In acidifying the water to 5.4 you are effectively measuring its alkalinity. Thus you cannot go wrong acidifying the sparge water to some pH below 6. But if it takes only a very small amount of acid to do that it is telling you that the alkalinity is low and that it isn't necessary.

 

[Rich819]

Thanks I forgot to add acid to sparge but preboil ph is 5.3 so I think Im fine

 

[ajdelange]

The issue is not as to whether the wort pH comes in too high or low but as to whether the runoff, at any time, reaches a pH higher than the high 5's in which case tannins may be extracted from grain husks. Clearly if you collect 19.9 gallons of wort before pH 6 is reached and the last 0.1 gal at pH >6 then you are not bringing much tannin into the beer. OTOH if you bust 6.0 when only half the wort has been collected (10 gal) you could be in trouble in this regard. It is also pretty clear that if you acidify the sparge water to 5.8 before the commencement of sparging you will not be busting pH 6.

It is best to monitor runoff pH during sparge now and then to get an idea of how long your runoff stays < 6 without treatment and base your decision to add acid or not on that.

 

[Tiber_Brew]

Just as AJ mentioned, I always acidify my sparge water to mid 5's pH so that I don't need to be concerned at any point about my runoff exceeding 6.0. It's a small effort for assurance, and I don't feel the need to measure runoff pH as I fill the kettle.

 

[Rich819]

Thanks very good information