Pre Boil Water vs Mash Guidelines

[Over The Cliff Brewing]

Since my equipment calcs the pre boli and post boil water amounts, how does this equate the amounts of water in the Mash Guidelines section? Example: In my Robobrew profile I listed 1.5qts/lb for mash. With a 10.5lb grain build that would mean approx. 4 gallons of strike water and roughly 2.8 gallons of sparge water. But after the calculated losses in the equipment profile, my pre boil water will be around 5 gallons. What am I missing? Is this why I am missing my gravity numbers? I hope this isn't too confusing. I cannot get the correct water volume and I'm thinking its because I dont understand the calcs. Help!!!!!!!

 

[Silver_Is_Money]

Lets say you want to yield 5 gallons:

10.5 Lbs. Grist x 0.12 = 1.26 gallons absorbed by the grist
Boil Off = ~1.00 gallons
Trub Loss = ~0.50 gallons (or perhaps a tad more)
Additional Aggregate Unrecoverable System Losses Not related to Absorption or Trub or Boil-Off = U

5 + 1.26 + 1.00 + 0.50 + U = Total Water Required

Lets presume U = 0.33 gallons of aggregate (overall) unrecoverable system losses are inherent throughout your system and process.

5 + 1.26 + 1.00 + 0.50 + 0.33 = Total Water Required
Total Water Required = 8.09 gallons

8.09 x 0.60 = 4.854 gallons of mash water
8.09 x 0.40 = 3.236 gallons of sparge water

 

[Over The Cliff Brewing]

I'll give it a try on my next batch. Thanks Silver!!

 

[Pricelessbrewing]

Thanks for the quick reply @Silver_Is_Money. If you have any more questions @Frankenbrewer please don't hestitate to ask.

We have a pretty big update still in the works for improving the mash guidelines, and QWR/volume calculations.

 

[Silver_Is_Money]

I'll give it a try on my next batch. Thanks Silver!!

Remember that the 0.33 gallons figure for 'U' is purely hypothetical, and the true value of 'U' for your system and process must be assessed.