Inconsistent mash pH with acid malt

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SpeedYellow

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Our LHBS just switched suppliers of acid malt (from Best to Weyermann, I think) and my recent batches had utterly failed to have predictable mash pH. A batch yesterday should have been 5.4 pH based on past experience but came it at 4.8! (with a calibrated meter and multiple measurements.)

Has anyone else found inconsistent acidification with acid malt? Perhaps using lactic acid is a better idea.
 
Wow! That is low.

I've had reports that the acidity of competing maltster products can be quite different. The supporter's version of Bru'n Water has a acidity adjustment setting that helps brewers account for that difference.
 
Yeah, I would definitely say that using lactic acid would be a better idea. Unless you're a German brewer that's trying to adhere to the German Beer Purity Law.
 
There is little question that 88% lactic acid from the LHBS is going to be more consistent than sauermalz from multiple suppliers but you tale does not ring true as it would require a super, duper sauermalz which the Weyermann's isn't. How much did you use (% total grist w/w)? What was the rest of the grain bill? What was the water like and how much was used? I have complete measurements on 2 samples of the Weyermann's and from the requested data I can tell whether what you saw is reasonable or not.
 
There is little question that 88% lactic acid from the LHBS is going to be more consistent than sauermalz from multiple suppliers but you tale does not ring true as it would require a super, duper sauermalz which the Weyermann's isn't. How much did you use (% total grist w/w)? What was the rest of the grain bill? What was the water like and how much was used? I have complete measurements on 2 samples of the Weyermann's and from the requested data I can tell whether what you saw is reasonable or not.

AJ - here's the recipe. (Lacto & fermentation details omitted for simplicity) I might note that the acid malt had quite a bit of flour ... like it was the bottom of a bag. That was a bit unusual.

Style: Berliner Weiss
Batch Size (fermenter): 4.40 gal
Estimated OG: 1.035 SG
Estimated Color: 5.6 SRM

Water:
- 50% Distilled, 50% Chicago filtered tap
- 2.0 g Calcium Chloride (Mash)
- 2.0 g Gypsum (Mash)

Ingredients:
------------
Amt Name
3.00 lb Wheat Malt, Dark (Weyermann) (7.0 SRM)
2.00 lb Pilsner - Bohemian Floor Malted (Weyermann)(2.0 SRM)
1.00 lb Vienna Malt (Best) (3.5 SRM)
0.25 lb Acid Malt (Weyermann) (3.0 SRM)
----------------------------
Infusion mash with 2.3 gal water. Mashout with another 3.0 gal water. Drain mash tun. No sparge.
 
I ran some quickey calculations and found that 4.8 isn't unreasonable for Weyermanns sauermalz and the rest of what you specified with all the attendant assumptions and caveats. So that casts suspicion on the old sauermalz. It must have been pretty wimpy stuff.
 
So that casts suspicion on the old sauermalz. It must have been pretty wimpy stuff.

There isn't enough difference between Best and Weyermann to account for that difference in pH. Best has a little less lactic potential, but only like 0.2 pH for similar percentages (<10%) for water RA of ~100, and I'm estimating high. For the recipe shown, I'd expect no more than 0.15 pH.

Best isn't a rare brand in on the market. I suspect an anomaly in this brew, not in the market.

So, I'll posit this: Acid malt isn't exactly a fast mover in a LHBS. What if the Best Acid malt was old? What if it had been replaced by fresher Weyermann's? Whether by oxygen or moisture (or something else), could the age have changed the pH potential?
 
I ran some quickey calculations and found that 4.8 isn't unreasonable for Weyermanns sauermalz and the rest of what you specified with all the attendant assumptions and caveats. So that casts suspicion on the old sauermalz. It must have been pretty wimpy stuff.
EZ Water predicts a pH of 5.4, while BrunWater predicts 5.2 based on my recipe above. And as I mentioned, the last time I brewed the same recipe, I saw 5.4. So this 4.8 kind of points to the Weyermann acid malt.

Regardless, I learned my lesson. No more acid malt for me.
 
That's too bad. Sauermalz adds a subtle complexity to beers that I like and, IMO, its easier to weigh out a pound or so of it while you are weighing out other grains than fiddle with lactic acid.

I don't know what happened here but I wouldn't blame the sauermalz (unless it was mislabeled, ancient or otherwise not what it was supposed to be. When I run pH estimates on your mash the grain I have trouble with is the wheat malt. Depending on how I model that I get pH estimates from 5.3 to under 5 and I don't really have a clue as to what a reasonable model is for it.
 
Funny you say that AJ, because I can never seem to predict mash pH well when using wheat malt.

Is there a simple way to test the acidity of acid malt? And "simple" would exclude titrations. ;)
 
Funny you say that AJ, because I can never seem to predict mash pH well when using wheat malt.
You would have to use a program which has an accurate model of it and as this sounds like a pretty unusual offering I'm guessing none does.

Is there a simple way to test the acidity of acid malt? And "simple" would exclude titrations. ;)

Grind up a measured weight. A spice grinder is great for this. Whatever you have you want a pretty fine grind when finished. Add DI water in about the same ratio you brew with. Now add small quantities of baking soda until you reach mash pH. Wait a while for pH readings to stabilize after each addition before adding another. When you reach mash pH divide the number of milligrams of bicarb added by 84. That's the acidity of the mass of malt you tested in mEq. Divide by the pounds or kg you tested. That's the acidity in mEq per kg or pound.

OK, it's a titration in reality but I hope a simple enough one.
 

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