Water volume calculations...please help.

[IanPC]

So I've tried online website calculators, home made calculators and Beersmith 2.0. They all give different water amounts when all the info is plugged in exactly the same. Weather it's strike water, sparge water, or pre-boil volume. Can anyone show me the long way of finding the total water volume, strike water and sparge water amounts. Your help in this matter would be very helpful.

 

[ApothecaryBrewing]

1. Measure your total amount of grains (lbs.)
2. Decide on the water to grain ratio you want (1.25quarts per pound up to 1.75 quarts per pound). 1.33 is a nice starting point. If you are using more roasted grains err closer to 1.5 or 1.75 to keep your mash pH stable.
3. Multiply your ratio by your grains to get how many quarts of STRIKE WATER you need. Divide by 4 for gallons.
4. Once you are mashing, measure out your SPARGE WATER. This is more of a rough approximation. If you are like me and do 5 gallon batches I find I typically need anywhere from 3-5 gallons of Sparge water so I always heat 5 gallons and just dump what I dont end up using
5. Take your first runnings and measure your volume. For a 5 gallon batch I typically get about 2-2.5 gallons from my first runnings. Since I boil off 1 gallon per hour I need about 4 more gallons to hit my pre-boil volume of 6.5 gallons. So I use 4 gallons of Sparge water. The grain wont absorb any more water (or a neglible amount) and the dead space has already been filled with strike water.

In order to dial in your volumes, you must know:

• your evaporation rate (water loss per hour of boil)
• mash tun dead space
• grain absorption amount (typically 0.15-0.2 gallons per pound of grain... so 10 lbs. of grain will probably soak up about a 1.5-2 gallons of water, will very so know your own and heat a bit more sparge water to err on the side of safety)

Lastly, invest in a gallon measuring device like a marked off pitcher or something. You can find them at restaurant supply store for $13, they will have 1-4 quart measurement markings... extremely useful for dialing in your volumes.

Each different piece of software you are using to generate your volumes probably has slightly different variables in terms of grain absorption, dead space and evaporation rate. This would most likely be why you are seeing variation in the volumes.