mash water help!

[ThirstyHobbit]

Hey all,
I'm doing my first all-grain tomorrow. It's a porter. The pre-boil volume is 7 gallons. I am adding strike water at 1 quart per pound. The grain bill is 15.5 lbs. If I add 1 quart per pound for striking, then sparge with (according to Papazian) half of the grain poundage in gallons, so 7.75 gal I feel like I'm going to have tooooo much water!

I know that some water will absorb in the mash, and I will have boil off (1 hr boil) but I'm concerned that I'll come up with too much water.

Anyone have some helpful advice??? I'm ready for all-grain but continue to be confused with the whole water part! Thanks!!!

 

[bull8042]

You will probably lose at least 2 gallons of water to grain absorption to begin with. But if you do end up with more water than anticipated, just plan a longer boil and delay your hop additions accordingly. No problems...

 

[Jonnio]

There are a couple ways to figure your sparge water.

1) Calculate how much dead space you have plus the absorption from the grain. Your first runnings will be your strike water minus those two. You then need enough sparge water to hit your pre-boil volume.

for instance - if you know that in a 60 minute boil your going to boil off 1.5 gallons and you want 5.5 in the fermenter your pre-boil volume is 7 gal. If you figure in a mash of 4.7 gal (1.25 qt per lb), .1 gal of dead space, and then figuring .125 gal per lb of absorption you will have about 4 gal of first runnings. So you need to sparge with 3 gal of water. My dead space and absorption tend to be a little higher than these numbers, so based on your recipe I would probably sparge with 4 gal.

2) is to heat up enough sparge water to cover extra beyond what you think you will need. Take your first runnings and measure how much you got. From there subtract your first runnings from your pre-boil volume and sparge. So say you collect 3.5 gal and you need 7, you sparge with 3.5 gal.

hope this helps

 

[Bobby_M]

Ok, so 15.5 lbs.. Just round off your strike to 4 gallons (16qts) to make it easy.

The grain will absorb about 1.5 gallons (.1 gallons per pound) so you'll get about 3.5 gallons out.

Arithmetic: 7g - 3.5 = 3.5 gallons to sparge with.

To Jonnio's point... measure your first runnings and subtract that from your desired 7 gallons preboil. Sparge with that amount. Graduated ale pails work well for measuring runnings volume.

 

[cactusgarrett]

I would start with the "standard" ratio to mash at 1.25qts/lb. Just crunching numbers:

That'll put you at ~19+qts. Assuming about .12gal/lb absorption (that's what i get), that puts you at (1.86gal x 4 = 7.44qts) an estimated first runnings (not including your deadspace) around 12quarts.

Are you batch sparging? I do, and here's where i deviate from Papazian, in that i'll use the amount of water for sparges to make up the difference from my first runnings to my desire pre-boil volume. This typically isn't half the grain poundage, so you take a slight hit in efficiency (I usually get around 70%). But that way, you aren't boiling for 2 hours to get your target post-boil volume where you want it.

In your case, i would do this:
Strike 19.5qts
First runnings ~12qts after absorption & dead volume
Pre-boil target = 7gal (28qts), so 28qts - 12qts = 16qts sparge water split between 2 sparges.
Sparge 1 = 8qts
Sparge 2 = 10-12qts.

I use more volume for the second sparge to save some runnings for future yeast starters, with the intention only collecting the same volume as sparge 1 to hit the pre-boil target. But, by adding more for the second sparge i leave myself with some potential to collect more if i need more to hit that target.

I know this was a lot of rambling and Cactus Brewery specific calculations, but that's what my typical calculations look like. Bottom line is if you come up with too much runnings, you don't necessarily have to use it for your wort. Freeze it for a future yeast starter.

 

[Mainebrew]

I also am in the same boat? I was wandering if there is a noob to all grain software that will do the math for me. I know its like I should learn the formula first but, it's like I want to run before walking. I plan on getting a cheap laptop just for brewing but want a good software program and I can put the grain bill in and let it do the math for me.

Thanks

 

[Jonnio]

both beersmith and beer tools pro will do it. You do have to do some equipment entry, but once set up it will tell you exactly what your mash/sparge water should be.

 

[cactusgarrett]

I was wandering if there is a noob to all grain software that will do the math for me.

I've got Beersmith, but when it comes to water volumes, I actually just made a simple Excel spreadsheet to calculate all that stuff for me. I find it quicker, simpler, and more accurate for my particular setup. I tell it things like what my desired mash thickness, pre and post-boil volumes etc. are and it tells me what to strike and sparge with.

Let me know if you're interested and i can send you the template.

 

[ThirstyHobbit]

could you send me that spreadsheet! Thanks!

 

[cactusgarrett]

No prob. If you could PM me your email address i can send it to you, along with some explanations.

Edit: or anyone else who want it, just PM me w/ your email address.