The CORRECT Batch Sparge Volume?

I've been mashing for awhile now, and I usually just wing it on the sparge volume. Not too smart, I know, but it's turned out okay so far. The major drawback, though, is that I can't adequately judge my pre-boil volumes prior to the brew session.

So, someone please fill me in on the correct sparge water volume for batch sparging. My Mephistopheles mashes in in less than 24 hours:

15.5 lbs of grain

19.06 qts of strike water

______ qts of sparge water

...what's the equation for determining that last number...? I learned mashing from Papazian, and his recipes always had specific sparge amounts, but never explained the equation so I could do it on my own. Thanks...

I'd be interested in knowing this also... Thanks..

Jester

Two variables you need. The first is the grain absorption rate. I've seen it estimated at 0.1 gallons / pound, but that always left me short, so I've been doubling that assumption and getting pretty close to right.

The second depends on your system; what kind of dead space do you have in your mash tun? With the Coleman Xtreme, I'm essentially at zero deadspace; for others, that's upwards of a half gallon. Since that's different for everybody, there is no one "right" answer.

I may be missing something in your process, but my suggestion is to simply sparge until you have two gallons over your target batch size. Back before I had my system figured out, I sometimes had to heat small quantities on the stove to get the tright amount. Now, If I'm doing a five gallon batch, I heat five gallons of sparge; if I'm doing ten, I heat ten. This leaves me with a couple of quarts left over, but that's ok.

Oh, I fly sparge, but amounts for batch sparging should be similar.

Hope this is helpful.. -p

The volume of sparge water is the same batch or fly, so any of the calculators will work.

Figure you'll get 100% of the first sparge back, so I drain and add the same volume as I used for mashing. Then I measure the first runnings and adjust the second sparge volume.

Dude - you are NOT going to like some of the answers you receive.

Do you like long boils? Low efficiency? Over-flowing mash tuns or boil kettles?

I don't think there is a right answer to this. My belief is that big beers are often harder to brew, and it is all about trade-offs. A good rule of thumb is to sparge with 1 to 2 volumes of your mash water, depending on the thickness of your mash. I think RichBrewer was suggesting about 2 qts per pound of grain is optimal. So your total water becomes something approaching 1 gallon per lb of grains. For a 15 lb batch, thats about 12 - 15 gallons of water to deal with, to be optimal.

The trade-off is that you can sparge with less water to get your boil volume down, but that will hurt your efficiency. Unfortunately, I haven't seen any good correction formulas that will allow you to predict the amount of loss in efficiency. I would guess that for your grainbill, if you collect 7 gallons of wort, you could expect a good 10% drop in efficiency because your sparge water-to-grain ratio has dropped so much, by comparison to a typical batch.

The good news is that you are already planning to add some DME -- best to have some extra on hand too. And it would be a good idea to check your SG before the boil and calculate your efficiency. If you really under-shoot, that is going to affect your hop utilization, which may need correction, too.

Hope the brew goes well -- looking forward to hearing about it!

EDIT: Just ran some numbers on 15.5 lbs of grain, and I guess it isn't that big (duh -- was deluded by your OG -- forgot this was actually a 'partial mash'). Just sparge to reach your boil volume, and you might take a few points hit on your efficiency if you are used to brewing with less grain, say only 10lbs per batch.

Okay, well, I'm designing my mash right now...I think about 7 gals would work for my sparge volume. If I split my wort into two kettles boiling side-by-side, what do you think my evap % rate per hour will be?

Looks like, to get down to 4.5 gals, I'm going to need to boil this bastard for-f*cking-ever. Damn.

I guess what I'll do is, since I'm going to be adding the LME late in the boil anyway, I'll just check my SG at 15 mins before flameout. If I need to add any extract at that point, I'll do it.

Evan! said:

If I split my wort into two kettles boiling side-by-side, what do you think my evap % rate per hour will be?

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Isn't the humidity level like 98% down in Virginia right now? That has a huge impact on evaporation rates (as well as total surface area, etc).

Prepare for a LONG boil, my friend....

the_bird said:

Isn't the humidity level like 98% down in Virginia right now? That has a huge impact on evaporation rates (as well as total surface area, etc).

Prepare for a LONG boil, my friend....

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Yeah, I do believe I could swim out my window right now if I wanted to.

Ugh. Well, good thing I don't have anything else to do. But I'll probably wake up at 5 just to get a nice head start. So do you have any ideas on the evap rate numbers? Just so I can plug it into ProMash...?

Easy rule of thumb is 1/2 your grain volume. Brewing software also helps to work out some of the specifics, but this has always worked for me.

tst4echo said:

Easy rule of thumb is 1/2 your grain volume. Brewing software also helps to work out some of the specifics, but this has always worked for me.

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Yeah, except my grain is measured in pounds and my water is measured in quarts.

evaporation rates article : http://byo.com/mrwizard/769.html

they say 6%-8% for home brewers per hour......I use 15% per hour and that works for me living in a very dry climate, at altitude, using a keggle.

(oh and Im going to happy hour = free beer at Avery this afternoon.... and im taking the bus for health precautions)

Thanks for the BYO link. I think the fact that I'm splitting my wort into two kettles will help.

Oh,
as an example with your figures

15.5 /2 = 7.75 gallons or 31 quarts. You should have used 4.26 gallons of water for the mash, so with all said you end up with 8.90 gallons in th kettle and 5.74 left over after boil. This is based on a 5 gallon batch.

tst4echo said:

Oh,
as an example with your figures

15.5 /2 = 7.75 gallons or 31 quarts. You should have used 4.26 gallons of water for the mash, so with all said you end up with 8.90 gallons in th kettle and 5.74 left over after boil. This is based on a 5 gallon batch.

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I actually thought I knew what you meant in the earlier post, but now I am confused.

How did you go from 7.75 gallons to 8.9 in the kettle?

sparge water plus water in the mastun adjust for loss in the grains and deadspace and you end up with 8.9 which is low depending on any dead space in your sparge container.

here are the numbers

7.25 gallons for sparge
4.26 gallons in mash
1.86 gallons loss in grain
= 9.65 gallons
.5 gallon (2qt) loss in mush tun deadspace
9.15 gallons in kettle. without any deadspace in sparge container.
8.9 gallons in kettle if you factor a 1 qt loss in sparge deadspace (depends on your container.)

OK, gotcha. You didn't say you were compensating for dead space. But that makes sense, for the most part.

One picky detail -- you said to use 7.75 gallons sparge water earlier, now it is 7.25. But I understand now how you did your calculations. I do something very similar.

Ah, I mistyped the 7.75. I would like to say I fat fingered it, but that would be a huge fat finger.

I think with the program I use, Beersmith, the sparge volumes for batch sparging are only based on getting the pre boil volume of water you desire, they aren't related to efficiency at all.

You can always measure the gravity after sparging some of the water to see what your efficiency is. If you aren't satisfied, you can sparge some more, and if you are you don't have alot of extra water to boil down.

I thought I'd give you my perspective on it. The formula is PV = MI - GA - MTDS + SV or desired preboil volume = Mash Infusion Volume - Grain Absorbtion - Mashtun Dead Space + sparge volume.

First, determine if you was a specific preboil volume or if you want to maximize efficiency. I want 7.5 gallons in the pot no matter what. I don't want to sit there boiling for 90 minutes.

Let's say you want 7.5g preboil and your grain bill is 12 lbs. At 1.25qt/lb, that's 15qts infusion or 3.75 gallons. I know based on my experience that grain absorbtion (if you'ved kept your stash in an airtight container) is about .5 qts per lb. In this case you're going to lose 6qts so your first runnings (assuming no dead space) is going to be 9qts (2.25 gallons).

Now you take your desired preboil of 7.5 - 2.25 = 5.25g sparge water which you'll want to break into to steps of 2.75 and 2.5 each.

If you don't really trust my numbers, the best thing to do is measure your first runnings the first couple times so you can be positive what your dead space and absorbtion is.

Again, the big decision is when you actually want to stop sparging. Do you keep running more water through until you hit 1.010 on the runnings or stop when you hit your preboil volume? I like the latter because I'm not that worried about hitting my gravity perfectly.

The highest efficiency I've ever hit included a mash out infusion and two equal sized sparges. (86%).

Haha, it's easy, just don't sparge! I just increase the grain bill and I'm on my way.

-RS

There is an excellent (and Free!) software program, Mash Water 3.3, on this page to figger out sparge amount & other water issues. Check the "Mash out" button, and it will set your sparge water to 2 equal volumes, which is what you want for batch sparging.

http://suburb.semo.net/jthornton/BeerHome.htm

just my .02
I use 1.30 to 1.33 qts per # of grain for my mash and I will loose 3 gal per 25 # of grain BUT I fly sparge for Eff. reasons never done a batch sparge.
JJ

Certainly don't want to turn this into a batch/fly debate, but I've gotten upwards of 86% batch sparging collecting only enough to require a 70 minute boil.

I tried a fly sparge on my last batch, and efficiency was nearly identical to what I've been getting with batch sparges...

PISS POOR!

Bobby_M said:

Certainly don't want to turn this into a batch/fly debate, but I've gotten upwards of 86% batch sparging collecting only enough to require a 70 minute boil.

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nope no debate here I would like to try a batch sparge but I am so comfortable doing a fly and I use the sparge time to do other things
JJ

Bobby_M said:

Certainly don't want to turn this into a batch/fly debate, but I've gotten upwards of 86% batch sparging collecting only enough to require a 70 minute boil.

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Hey, that's really good. My most recent batch was 80%, but that was using my Porkert (Corona) mill, so I don't think I am going to improve much now. Regardless, I am perfectly happy with that and doubt I will try fly sparging, get a new mill, etc. just to go up a few points.

Bobby, I am curious -- what was the OG of that 86% brew you did? Under 1.065 or over?

Read Denny's site. It gives the calculations
http://hbd.org/cascade/dennybrew/
It is trial and error to start, but after you fiqure out your system you'll get half of your total boil amount first run, the other half second run.
Also see
http://www.tastybrew.com/calculators/

I fly sparge, but the calculations for sparge water remain relatively constant. I greatly simplify these calculations by using BeerSmith to formulate the recipe, knowing that I like to boil about 17.5 gallons of wort to get about 15 gallons of beer in the end, and that I easily get 75-80% efficiency.

I generally mash with 1.25 quarts of water per pound of grain. My average grain bill is 30 to 40 pounds of grain, absorbing approximately 1 gallon per 10 lbs of grain. So, I dough in with 10-12 gallons of water. The grain will absorb 3-4 gallons of that water, leaving me with 7-8 gallons of first runnings. Therefore, I'll need roughly 10 gallons of sparge water to get my desired volume. I usually have 15 gallons of sparge water available just in case.

I hit 86% on a 1.044 ordinary bitter and then the next batch was 80% on a 1.042 blonde ale.

On the bitter, I used a mash out + two batch sparges. The SG on the last runnings was 1.010.

On the Blonde, I didn't infuse a mash out but did two sparges, last runnings were still 1.020 but I had my desired volume.

I'm sticking with mash out infusions....