Weyermann's acid malt is an acidulated malt that contains a small percentage of lactic acid (usually around 1 to 2% by weight) on the husks. It is used to adjust mash pH in beer. Weyermann states on their web site that reducing mash pH can lead to a better mash, intensified fermentation, lighter color for Pilsners, improved flavor stability and a well-rounded beer flavor. Acid malt is usually used in small proportions to adjust pH. It has been noted that for every 1% of the grist comprised of acid malt, a 0.1 drop in pH can be expected. Usually used as 1 to 5% of the grist for pH adjustment, it can also be used at a rate of 8 to 10% of the grist for sour beers such as Berliner Weiss to bring out sour character. Many people also use a small percentage (around 3%) in classic dry Irish stouts to give a characteristic sour note on the finish.
| Crush Grains? | Yes or No |
| Grain Bill | Grain Bill 1 or Grain Bill 2 or Grain Bill 3 or Grain Bill 4 or Grain Bill 5 or Grain Bill 6 or Separate |
| Country of Origin | Germany |
| Malt Color | 1.7-2.8L |
| Protein | 10.1% |
| Moisture | 4% |
| Extract | 75% |
| Diastatic Power | 0 |
| Usage | 1 to 5%, Up to 10% in Sour Beers |
| Brand | Weyermann Malts |