I need some help from someone who has done a turbid mash for a lambic before...
I've been reading over the turbid mash procedures in the July/Aug '08 issue of BYO, as well as the Wild Brews book. The problem I'm having is that in both cases the infusion amounts, target temperature, and water to grain ratio don't add up. For example the BYO article states that after each infusion with 212 F water you should end with a ratio of 0.3 qts/lb, 0.45, 0.65, and 0.65 respectively at the end of each infusion. This is all well and good but the water needed to raise the mash the degrees specified don't get you to those ratios. They fall far less, which if you calculate it out results in you not having enough liquid in the mash at the end to exchange with whats in the stuykmanden.
The Wild brews description (on page 141) is similar in that the calculations don't make sense. This article has you using 20-30% of the brew water for each infusion for relatively small temperature steps (e.g. 13 or 26 F). Calculating it this out, you end up with much higher mash temps then desired.
Anyone know why this doesn't add up? I know a thinner mash will result in more heat loss, but is that the only factor? Does un-malted wheat lose heat faster than malted barley?
Currently my thinking is that I will have to adjust the infusion temperature to either mash the volume of the Wild Brews example or the ratio of the BYO article. Any suggestions from experience?
FYI - I wrote to BYO hoping the author might be able to help. I will post a follow up if I get a response.
Thanks in advance for your help. Cheers!