How much water to start with

[Kansasstatefootball]

Rookie question…I’ve only done a few brews now from 5 gallon kits but came across a clone that I’d like to try that’s 7 gallons. I have all the grains, hops, etc. How do I know how much water to start with? Is there some calculator somewhere I’m missing? Does 10 gallons to start with sounds about right?

 

[doug293cz]

There are lots of calculators for brewing recipe and volume calculations: BeerSmith, BrewersFriend, BrewFather, etc. But they all require information about the volume losses that occur throughout your brewing process: grain absorption rate, mash tun losses, boil-off volume, trub losses in boil kettle, and trub losses in the fermenter. Without knowing your volume losses during your process, it is not possible to give a simple answer on how much water you need to start with.

Another question: do you have capacity to ferment 7 gallons? If not, then you should scale the recipe to a smaller volume. Brewing calculators can help you with scaling.

Brew on

 

[SFC Rudy]

Info:
1 lb grain will absorb.125 gallon (1/2 qt) of water.

What is your boil volume?
What is the grain bill?

Let’s assume the boil volume is 6 gallons with a 10 lbs grain bill.

10lbs grain x .125 gal = 1.25 gallons water absorption. So you would need 7.25 gallons of strike water to get 6 gallons of wort.

Then you need to account for losses, you have to brew to find these loses in your system. If you add the 7.25 gallons and only get 5.5 gallons, you need to find where you lost the .5 gallon of wort and see if you can recover it. If not then you have to add an extra .5 gallon of strike water next time.

How to Brew by John Palmer has all the math. Myself I put it in an excel spreadsheet and tailored it to my system.

 

[worlddivides]

I use this, but I find it to be extremely accurate:

https://pricelessbrewing.github.io/BiabCalc/#Advanced

In my case, I do BIAB, but if you don't, there are tons for more typical three-vessel systems online.

 

[IslandLizard]

Then you need to account for losses

Here are a few guidelines:

1. Boil-off (kettle)
This can easily be 1 gallon per hour, and depends on your heat source and how high it's cranked up. A mere simmer (surface rippling) during an hour boil is usually enough.
Grist containing a high percentage of Pilsen malt may need a 90 minute boil to drive off DMS sufficiently.
Boil-off tends to be relatively higher with smaller batches. For example, boiling a 2 gallon batch may boil off about the same amount as a 5 gallon batch.

2. Trub loss in the kettle
How much wort will be left behind in the kettle after transferring to the fermenter, due to hop pulp, grain dust, protein precipitate, etc. Some of that is recoverable if you want to take the effort. I typically do.

3. Trub loss in the fermenter
Typically yeast, dry hop pulp/dust, and other precipitates that settle out after fermentation has completed.
If you're cold crashing that can be a well compacted cake. That will help limiting beer loss during transfer to keg or bottling bucket. Be diligent with the siphon. Train yourself with a bucket of water to get the hang of the method.
Also tilting the fermenter toward the end of the transfer to keep the siphoning well deep, prevents sucking up trub, and increasing your beer yield.

On a side note:
Sparging your grist after the mash has been lautered (drained) will increase the extracted sugar amount, and raise your mash efficiency. How you sparge depends on your mashing system.

 

[VikeMan]

To get Total Water volume needed...

Desired batch size into the fermenter
+ grain absorption
+ unrecoverable mash tun dead space
+ tun to kettle transfer losses
+ kettle hop/trub absorption
+ boil off
+ kettle to fermenter transfer losses.

 

[hungupdown]

Rookie question…I’ve only done a few brews now from 5 gallon kits but came across a clone that I’d like to try that’s 7 gallons. I have all the grains, hops, etc. How do I know how much water to start with? Is there some calculator somewhere I’m missing? Does 10 gallons to start with sounds about right?

If youre doing a sparge, 10 gallons of mash water sounds too high. You'd end up needing a very long boil.

I use Brewfather (Web app) for calculating my recipes. The free version saves up to 10 recipes.
It has numerous equipment profiles to choose from. But I find brewfather (default profile for my AIO system), always gave too thick a mash.

You could try 5 gal mash water, and a 2 gal sparge. Then, while starting boil, separately sparge with an extra 1/2 gal. Saving this for a top up, if boil volume is getting low.

 

[Kansasstatefootball]

There are lots of calculators for brewing recipe and volume calculations: BeerSmith, BrewersFriend, BrewFather, etc. But they all require information about the volume losses that occur throughout your brewing process: grain absorption rate, mash tun losses, boil-off volume, trub losses in boil kettle, and trub losses in the fermenter. Without knowing your volume losses during your process, it is not possible to give a simple answer on how much water you need to start with.

Another question: do you have capacity to ferment 7 gallons? If not, then you should scale the recipe to a smaller volume. Brewing calculators can help you with scaling.

Brew on

I do have the capacity but would rather stick with 5 gallons. I’ve very new to Brewfather and just figured out how to scale it back. I feel much better about that. Thanks for the help!

 

[mashdar]

You can typically linearly scale ingredients. I.e. if you want a 5 gallon recipe, and are starting with a 7 gallon recipe, multiply all ingredients by 5/7.**

Per above, assuming 60 minute boil, and 10 lbs if malt, I'd guess you need ~7.75 gallons to start. Thats for 1.25 gallons lost to the grain, 1 gallon boil-off, and 0.5 gallon misc losses (hops, stuck in kettle, etc)

Personally, I shoot for 5.5-5.75 gallons to make sure I can fill a keg all the way.

**You often need to adjust for your efficiency. If the author has 85% mash efficiency, and you have 75%, you might add grain to hit the OG