German Pilsner
5.5 gallon batch
7.5 gallon BIAB
10.5 lbs pilsner
0.5 lb light Munich
base water is extremely low mineral with a 8.3pH
target mash pH 5.3
8g gypsum
using 10% phosphoric acid
Bru’n water recommends 23mL of acid
Brewersfriend.com recommends 49mL of acid
chatgpt says 30-50mL of acid
I don’t have a pH meter and my water has been tested at Ward labs.
That is quite the large discrepancy in acid additions. Any suggestions?
Unfortunately, that isn’t enough detail to enable what an acid addition should be. Water pH is useless in brewing.
ChatGPT will not give good recommendations here. It is a text parser, which strings together words following observed past patterns in text it has been fed. I would not use it for calculations.
I have my water report entered into Bru’n water.
Ca = 6.4
Mg = 3.0
Na = 8.3
HCO3 = 39
Cl = 4.0
reported alkalinity = 33.0
pH = 8.3
So what other information would I need? More of what my question is, why is there such a discrepancy among the two different brewing calculators?
Martin,
I recently re-listened to your interview with Doug on the Gourmet Podcast.
I cross referenced a comment you made concerning lactic acid against your Water Knowledge page.
I still need clarification: the ‘standard’ you give for lactic acid is 1 ml per gallon (I’ve heard others say 1-1.1 ml per gallon).
Is this gallon of finished beer, gallon of mash (strike only) (strike + sparge) (BIAB total mash volume) or…?
Thx. Dwain
1 mL per gallon is a very safe limit for 88% lactic acid use, but some super tasters might still pick it up in beer. I find lactic flavor to be natural and pleasing in many beers, but most brewing won’t produce a beer with much lactate flavor. It’s only very alkaline water sources that could have this problem.
With respect to which water volume to assess the acid dose against, it would be the total volume of strike and sparging water used to produce the brew.
Thank you!