Aciduated Malt

[brewmaster 2011]

Any one use more then 4% weyermann aciduated malt to lower the mash ph? and if so did the beer end up with a sour taste or a clean taste?

[BelgianBrews]

I have used 5% Weyermann acidulated to drop the mash pH and give a subtle tartness to a Belgian style beer. I believe Weyermann recommends not going above 10%. In general, 1% of the total grist is intended to drop mash pH by one tenth of a point. Of course, this depends on several other factors including your grist load, but more importantly your brewing water. High carbonate hardness will act as a buffer against acidic conditions in the mash, so your mileage may vary. I am no expert in water chemistry, but in my experience when working with moderately hard, soft, and very soft water, Weyermann's predicted drop of one tenth of a point in pH for each 1% of acidulated in the grist load has proven to be an accurate and effective method to lower mash pH. Typically I only need between 1 and 2.5% to hit a mash pH in the range of 5.2-5.4. I don't think you should expect a sour taste from acidulated malt unless your finished beer pH is well below 4. You may get some tartness, but I would describe it as a clean tartness. Then again, the time I used 5% I was using a very expressive Belgian yeast in a high gravity beer fermented in the mid 80s. If you are just trying to get into the proper mash range you should not need more than 4%. If you do, you need to figure out a way to improve your water.

[jwalts]

I agree with BelgianBrews, and I'll add a little to his post. If the acid in the malt is eliminating alkalinity and your mash pH ends up in the correct range, your beer shouldn't be sour regardless of the percentage used. It may be astringent, though, because using acidulated malt is like treating your mash water but not your sparge water. If you need more than 1-2%, you should probably (at the very least) figure out a way to reduce the alkalinity of your sparge water.

Joe

[WaterEng]

As Joe mentions, if the mash pH is falling into the desirable range, an acid addition should not make the beer sour. But if the amount of acid is large, the quantity of the anion added with that acid may have an effect on flavor. With Acid Malt, the lactate ion can have a flavor effect. Four percent addition might have a flavor effect.

Joe also raises a good point for those of you needing to acidify your mashes with Acid Malt. If this is the case, its probably important that the sparging water also be acidified to reduce its alkalinity to avoid tannin extraction during the sparge and raising the overall pH of the runnings in the kettle.

The phenomena of 1 percent Acid Malt addition causing a 0.1 unit pH suppression is interesting. As any of you who have played with acidifying an alkaline water know, the pH changes little during the early incremental acid additions and then drops like a rock at some point. This is the bi-modal response of initially consuming the alkalinity and then the true acidification. In the case of the mash, it provides the bulk of the alkalinity consumption. That allows the Acid Malt additions to produce the relatively linear pH reduction with respect to quantity added.