I’ve been getting about 75% efficiency with my single infusion, batch sparge mashes, but I suspect I might be able to do better. My water source is relatively soft and, when I plug the numbers into John Palmer’s nomograph on the back cover of “How to Brew”, it appears that my mash pH is around 5.8, suggesting my water source is most appropriate for amber colored beers.
I’m thinking about a couple of ways to lower the mash pH and make it more appropriate for the lighter style Belgian beers I brew (tripels, strong goldens, saisons, BPAs, etc). One would be doing an acid rest and the other approach would be adding acidulated malt.
I’ve heard that an acid rest may help to create acids by activating phytase, but that this takes quite a length of time to happen (hours?). A staff person at a homebrew supply store told me he does this (he uses the same water source and mash process as me) and his mash efficiencies are regularly in the mid 80s. I’m dubious and not too excited about trying to get the temperature right by adding more hot water to get the temp to mash temps since I’ve found the calculators don’t always work very well with water additions.
I’m frankly more interested in adding acidulated malt, but am unsure of how much I’d need to add – Palmer talks about up to 10%. I thought I’d start with 1% of my grain weight and add more in each batch to see what effect it has in mash efficiency.
Maybe I’m already fine with 75%, but if it’s just a simple matter of a few ounces of acid malt for better efficiency (perhaps even better taste), I’d say that’s great.
The third option is going to take me a little longer to understand – adjusting water chemistry. According to my initial attempts with online calculators, it would likely be a matter of a couple of grams of gypsum and calcium chloride. While that doesn’t sound like a lot, my guess is that it could actually be quite a bit of mineral to add and I’m not sure I want to waste a batch trying until I get a sense of proportion.
As usual, thanks for any and all help.