Wheat beer mash PH problem

[TahoeRy]

I just started a wheat beer mash in which I am using 7 lbs of wheat (Weyermann Floor Malted Bohemian Wheat Malt), 6 lbs of 2-row and 1/2 lb of caramunich. Normally, I only need to add about 1/2 - 1 tsp of Gypsum to lower my mash ph to around 5.3 (my water has a ph of 8.03). This time I had to add 6 tsp to get my ph to 5.6 and I couldn't get it any lower. I was afraid to add more gypsum to try to lower it more as I know I am effecting my water chemistry and don't want to throw my great water off to much. I live in Lake Tahoe and our water is awesome, very close to Pilsen, Czech water chemistry and I try to embrace that in my beers. Has anybody else experienced this? Did I mess up here by adding so much gypsum? Any info would be great. Its getting to that time of year to start getting the spring / summer beers in the fermentors and I would love to find a way to get my mash ph down to proper levels without effecting my water chemistry to much.

Thanks in advance for any responses.

 

[mabrungard]

Trying to harden the water to achieve mash pH is not very effective and can easily result in excessive sulfate or chloride in the wort. Using an acid would be much more effective. Given the very low alkalinity of Tahoe water, it would take very little acid to reach an acceptable mash pH. Recognize that the tap water pH is meaningless in brewing. Only the ionic content of the water matters. They create mash pH in conjunction with the grist.

 

[TahoeRy]

So switching to an acid based ph reducer would be a better approach? I always used gypsum but certainly had a problem with that today. I will do just that and get an acid based ph reducer for my mashing. Thanks for the input.

 

[mabrungard]

Since the alkalinity of that water is low, you could easily use lactic acid. Phosphoric is also a good choice, but its often less available in some locales.