As we know from several sources, Rahr base malts tend to produce a mash pH that is a couple of tenths lower than other similar base malts. I just finished up a brew using a large percentage of Rahr 2-row Pale and was able to verify a corrective input for Bru’n Water that accounts for the higher acidity Rahr malt.
I recommend increasing the color rating of the Rahr base malt by about 3 lovibond to account for the extra acidity. For example, for a Rahr Pale malt with a color rating of 2 L, input the color rating as 5 L in Bru’n Water. That will improve the accuracy of the mash pH prediction.
Wow, talk about a coincidence. I was just getting ready to buy a sack of Rahr Pale Ale Malt. Does it apply for the darker stuff as well (kinda like Denny asked)? Should I bump it up to around 6.5 L?
I don’t know why their base malts produce this effect. I just know that its true. I don’t know that the darker malts have that effect, but their limited percentage in most grists probably make that feature inconsequential.
I’ve hypothesized that this is actually a good thing for most brewers since most of the county’s water supplies are alkaline (see the alkalinity map that I posted on the Water Knowledge page at the Bru’n Water website). So having a base malt that helps combat that alkaline water is likely to improve beers in which the brewer hasn’t learned the fine points of mash pH adjustment. So, its a win-win for the brewer and the maltster. But for brewers that use a program like Bru’n Water, they need to know that Rahr malts are likely to drive their mash pH down a bit more than expected. That isn’t a bad thing, but it is something that the brewer should know about beforehand. Bru’n Water is all about predicting and creating a desirable mash pH and beer outcome!
Thanks Martin, is their a way to import the data form an older version of Bru’n Water into the current version? Or, is their a quicker way of accomplishing that, then by doing it manually?
Assuming that the final beer pH is somewhat influenced by the mash pH, I wonder if the flavor of certain beers are enhanced by lower pH? Like wine, too high of pH and its flabby. I’m thinking the sharper flaovrs of citrusy hops might be enhanced by more acid, whereas a malt-forward beer might seem smoother at a higher pH.
Not necessarily, Higher pH helps accentuate hops since they are an ‘acid’. The alpha acids do present themselves more with slightly higher pH. In last yea’rs Water Panel, Colin mentioned that he has noticed that low wort pH reduces the hop expression. For that reason, I feel that maltier beers tend to present a little better with a slightly low wort pH. I extrapolate that the reduction in the hop expression allows the malt to shine more and its crisper and cleaner.
Gave myself a nice GIMF thats Google It My Friend or something like that) and then found some pKas. Not surprisingly the various acids have different pKas, some of the common ones are in the 4.5-6 pH range though. So I suppose theres some possibility that we are affecting solubility, or flavor due to the form the acid is in.
I have known about this issue for a while. It’s not just Rahr 2-row that is a poor fit to the pH or acidity estimation based on malt color. Wheat malts tend to have a DI water pH closer to 6 and I once had a vienna malt that has a DI pH at 5.8.
That’s a general limitation of all color based pH estimation (grist or beer color based). I just released the new water calculator for Brewer’s Friend (http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator) and in future releases we plan to integrate it with the recipe editor. That way we can keep pH properties of some malts, like Rahr or Weyermann, in the grain library and the tool doesn’t have to estimate their pH from color.
I haven’t tried the pilsner malt, but if it’s the same barley cultivar I would expect that. Maybe the PH will be a bit higher since it id kilned to a lower color.