Lactic acid or gypsum to lower mash ph?

[blkandrust]

New to the water game.I want to brew an IPA next weekend and ran the numbers through bru n water with a predicted mash ph of 5.83. Which method would be the best way to bring my ph down to 5.2? Thanks in advance.

 

[Yooper]

Phosphoric acid would be the best choice. Gypsum will enhance the flavor, but doesn't move pH as much as you need in this case. Lactic acid works, as long as you're below the flavor threshold but phosphoric acid is flavor neutral.

 

[blkandrust]

Thank you for the reply.According to bru n water,I would need 31.74 ml of 10% Phosphoric acid to bring my ph to 5.26 from 5.6.I understand its flavor neutral but is that a lot? Maybe I entered it wrong?

 

[Robert65]

FWIW I use lactic acid 88% and have never encountered a situation where the requirement approached the taste threshold for lactate.

 

[day_trippr]

fwiw, I've added as much as 15ml of 25% PA to some uber-light 10 gallon batches, so 32ml of 10% isn't excessive imo...

Cheers!

 

[Silver_Is_Money]

If you bring your room temperature mash pH down to 5.2, your actual mash pH at 65 degrees C. will be about 4.9. That is well below the optimum pH at 65 degrees C. for alpha and beta amylase enzymes.

 

[blkandrust]

If you bring your room temperature mash pH down to 5.2, your actual mash pH at 65 degrees C. will be about 4.9. That is well below the optimum pH at 65 degrees C. for alpha and beta amylase enzymes.

So should I be aiming for a 5.5 room temp mash? Perhaps bru n water has this correction available and I missed it?

 

[Silver_Is_Money]

So should I be aiming for a 5.5 room temp mash? Perhaps bru n water has this correction available and I missed it?

Personally, I would aim even higher, and target 5.6. That is 5.3 pH at mash temperature, and smack in the ideal zones for the enzymes.

Then post boil and cooling measure again and adjust to pH 5.2.

 

[Yooper]

Thank you for the reply.According to bru n water,I would need 31.74 ml of 10% Phosphoric acid to bring my ph to 5.26 from 5.6.I understand its flavor neutral but is that a lot? Maybe I entered it wrong?

Nope, not a lot at all. That's fine!
I always use a goal of 5.3ish to 5.4 for lighter colored beers, and 5.5 ish for stouts.
When we talk about mash pH, we are always talking about room temperature, not mash temperature, and you'd be great right in that ballpark. You would of course cool your sample, and take the reading.

 

[Vale71]

Thank you for the reply.According to bru n water,I would need 31.74 ml of 10% Phosphoric acid to bring my ph to 5.26 from 5.6.I understand its flavor neutral but is that a lot? Maybe I entered it wrong?

10% phosphoric is pretty weak so it's no wonder you'll have to add that much. Personally, I use the 80% and the additions don't seem quite that huge.