Water volume needed

[Clanchief]

I put together a recipe for brewing an IPA this weekend. I plugged it into Beersmith, as I'm wont to do, and check the recommended numbers for my mash and the sparging. Lo and behold, for a 5.25-gallon batch, it's saying I'm going to need 11.75 gallons of water. I know that I'll lose some water to the grains, and some wort to the boil, but 6.5 gallons worth? Doesn't seem likely to me.

So, I could use some help in calculating what I would actually need in terms of water. Here's the grain bill:

7.5# Briess 2-row
3# Pilsner malt
1.25# Crystal 60

Thoughts?

 

[Hopper5000]

lower your sparge and strike quarts to pounds ratios. E.G. only strike with 1.1 or 1.2 quarts per pound and then just sparge up to you pre-boil volume or strike with 1.5 quarts per pound of grain and sparge with less water. Do you know what your boil off and other losses are? If you are going for a 5.25 gallon batch I would assume that you won't need more than 6.5 to 7 gallons for boiling in the kettle.

 

[kombat]

11.75 lb of grain will absorb 1.175 gallons of water. Figure a quart of dead space in your mash tun, another 2 quarts in your boil kettle, that's 7.7 quarts gone. If you lose a gallon during a 60 minute boil, that brings the total loss to 11.7 quarts, so if you wanted to end up with 6.5 gallons, you'd have to start with 9.425 gallons in total.

Hmm, we're still off by 2 whole gallons, so yes, it sounds like your equipment profile in BeerSmith could use a little more tweaking. Check the loss to trub and the chiller, and the deadspace in your kettle and mash tun, and the boil off rate.

EDIT: Ah, I just noticed the 3 pounds of Pilsener malt, which means it'll be a 90 minute boil, not a 60 minute. So there'll be a little more boil-off (maybe 1.5 gallons?) which means my estimate was only off by 1.5 gallons, rather than 2. But still, seems overly pessimistic.

 

[Clanchief]

lower your sparge and strike quarts to pounds ratios. E.G. only strike with 1.1 or 1.2 quarts per pound and then just sparge up to you pre-boil volume or strike with 1.5 quarts per pound of grain and sparge with less water. Do you know what your boil off and other losses are? If you are going for a 5.25 gallon batch I would assume that you won't need more than 6.5 to 7 gallons for boiling in the kettle.

I find that to get 5.25 in the fermenter, I need around 6.75 gallons in the kettle. Which is why these numbers seem so crazy to me. It's weird, because I haven't changed my equipment profile in the software at all, and it's always been pretty much spot on previously. Then today it seems to go crazy.

Thanks for the numbers. I'll do the math and figure out what I need.

 

[Clanchief]

11.75 lb of grain will absorb 1.175 gallons of water. Figure a quart of dead space in your mash tun, another 2 quarts in your boil kettle, that's 7.7 quarts gone. If you lose a gallon during a 60 minute boil, that brings the total loss to 11.7 quarts, so if you wanted to end up with 6.5 gallons, you'd have to start with 9.425 gallons in total.

Hmm, we're still off by 2 whole gallons, so yes, it sounds like your equipment profile in BeerSmith could use a little more tweaking. Check the loss to trub and the chiller, and the deadspace in your kettle and mash tun, and the boil off rate.

EDIT: Ah, I just noticed the 3 pounds of Pilsener malt, which means it'll be a 90 minute boil, not a 60 minute. So there'll be a little more boil-off (maybe 1.5 gallons?) which means my estimate was only off by 1.5 gallons, rather than 2. But still, seems overly pessimistic.

Actually I'm only going for 5.25 gallons, not 6.5. So it's a still a really large difference, even with the 90 minute boil. A roiling boil for 90 minutes, I'm not going to lose more than 1.5 gallons, maybe 1.75.

 

[Hopper5000]

I would strike with 15q of water (using a 1.2q per pound strike ratio) and use about 20q to sparge and then just sparge up to 6.75 gal in your kettle. 20q sparge should be enough water if not a little excess but I always over shoot a bit just in case. Just make sure your sparge doesn't get below about 1.008 on the runnings or you risk extracting tannins. If you think that is too much sparge water then add a couple more quarts to the strike and sparge a bit less. Generally the more water you add into the strike the more room there is for the enzymes to convert the starches into sugars. However if you start getting above 1.5q to 2q per pound I believe it starts becoming detrimental...

 

[Clanchief]

Yeah, I just ran the numbers and I think I'm going to go with 16 quarts of strike, then 18 sparge, since it is a 90 minute boil and I want to make sure I have enough. That should give me 31.7 quarts give or take for the boil, which should come down to no less than 5.5 gallons. Even with loss in the trub, I should have plenty left over.

 

[Super64]

I've read several threads here, plus other sites concerning the percentage of loss during the boil.

Not thinking about efficiencies, just on pure volume, with a post boil target of 3 gallons, I consistently lose 40-48%.

So with nearly 5 gallons of pre-boil volume (4.75) at 60 minutes, I've got 2.75 gallons left before the trub loss.

I just completed my last batch at 5.75 gallons in an 11 gallon boil pot for 90 minutes and there was 3 gallons left.

After removing it from the trub, I'm down to 2.5 gallons in the primary.

Mind you, I run boil at the "vigorous" level, once 212 degrees is reached, I don't back off the burner.

So, what's the trick to getting boil losses down to the 15%-20% range?