Batch sparge - water calculations advice.

Hello.

I am brewing an IPA using the following grains:

14# 4oz Canadian Two-row Pale
1# 1.637oz Caramel/Crystal Malt - 40L (500g)
8oz Toasted Malt (pale malt for 10mins @350F)

This will be for a 6-gallon batch. Based on 75% efficiency, I would end up with an OG of 1.073.

This will be my 2nd time doing an all-grain brew. The first time, I tried fly sparging but I had a lot of trouble with temperature control so I would like to give batch sparging a try this time.

I have a 48-quart cooler with a single SS braid.

I am doing a single infusion mash at 153F. Assuming 65F grain.

If I go with a 1.0 ratio of water to grain, I would need 4.03 gal at 171F. Then I would add 2.05 gal boiling water to reach 170F for the mash out.

If I go with a 1.25 ratio, I would need 5.03 gal at 167F. Then I would add 2.48 gal of boiling water to reach 170F for the mash-out.

Assuming 1.6 gallons will be absorbed (is that safe given those grains?)... and an 8 gallon pre-boil volume.

With the 1.0 ratio, I would drain 4.48 gallons and would need an additional 3.52 gallons in sparge water.

With the 1.25 ratio, I would drain 5.91 gallons and need 2.09 gallons in sparge water.

Given the target OG of 1.073, does an 8 gallon pre-boil volume make sense or should I sparge more and boil longer?

Which ratio makes more sense or should I meet halfway and go with ~1.1?

After the first draining, should I split the sparge water additions in 2 additions or do it all at once?

Thanks for any and all of your help!

I always do 1 to 1 but most people like to use more water although I have no idea why. It's almost like they fear it or think more is better for some reason. A thick mash holds its temp better and allows for the use of more Sparge water. Both benefits.

You would get better efficiency if you split your sparge as you will end up stirring it twice which helps with extracting the sugars.

I would recommend downloading my brew chart in my signature below (it's free). It will take care of all the math/calculations for you to maximize your potential efficiency for batch sparging plus a whole lot more.

If you have any questions please don't hesitate to ask.

cp

If you have a Droid there are some really good apps for that.

I would recommend downloading my brew chart in my signature below (it's free). It will take care of all the math/calculations for you to maximize your potential efficiency for batch sparging plus a whole lot more.

If you have any questions please don't hesitate to ask.

cp
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CP's Brew Chart: http://rapidshare.com/files/448162486/CP_s_Brew_Chart_3.0.xls

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That is an incredibly helpful tool from CP. Thanks alot, I will definitely get use out of that!

1.6 gallons absorb is a good estimate, but on the low side. Could be as high as 1.9. But it doesn't really matter. After you get your first runnings, just divide the remaining amount of volume to get your pre-boil by 2 and batch sparge twice using that volume. You want enough sparge water that you can easily stir the mash to coax the sugar out into solution. If you can't get that with 2 batch sparges, just do it all at once. You might lose a few points in efficiency but nothing too big.

As far as the mash thickness, if you are set on doing the mash out then you want to go with the 1.0 otherwise you will not have enough sparging before you get your pre-boil volume and you will lose quite a bit of efficiency.

And speaking of pre-boil, 8 gallons seems like a lot to begin with. How long is your boil? Did you happen to measure your pre and post-boil volumes last time? 2 gallons seems to be on the high side for boil-off. My cheap propane burner and 30-quart kettle is between 0.75-1.25 gallons per hour.

If you didn't measure the volumes last time, definitely do it this go around. I also recommend taking and recording volumes and gravities of your first runnings as well as your sparge(s). This helps you troubleshoot efficiency problems if you have them, but also will let you plan subsequent batches with more confidence, e.g. Parti-gyle brewing.

All in all, looks good to me. FWIW, I have 20 or so AG batches under my belt. Not a noobie but still learn something every time.

Thanks for the help everyone.

I will go with a 1:1 ratio this time.

Do you go with 185F for your sparge water? Do you skip the mash-out?

The last time I didn't have a large enough pot so I split the wort in to two pots on the stove and lost 2.5 gallons over an hour (and had a steamed up cupboard of glasses to prove it!). This time I am boiling it in one pot on a propane burner. I would be fine to start with 8 gallons and if I end up with a little more than 6, that's fine because I have an 8.5 gallon bucket for my primary and a 6.5 gallon carboy for conditioning.

Burro2882 said:

That is an incredibly helpful tool from CP. Thanks alot, I will definitely get use out of that!

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No problem, that's what I designed it for so glad to hear you like it. If you have any questions don't hesitate to ask. There is a thread over on the beer software section dedicated to it. I like feedback/questions as it helps with further improvements.

cp

If you're batch sparging, I'd suggest dropping the mash out and just adding that volume to the sparge water. Do two equal batch sparges, and no mashout, after the mash.

I almost always mash at 1.33 to 1.5 quarts of water per pound of grain. There are a couple of reasons- one is pH. The other is that if you do that, when you figure out the water volumes, you'll find that you get out 1/3 of the runnings from the mash, 1/3 from the first sparge, and 1/3 from the second sparge. That's about perfect in dealing with volumes and pH for me.

hogie1980 said:

Thanks for the help everyone.

I will go with a 1:1 ratio this time.

Do you go with 185F for your sparge water? Do you skip the mash-out?

The last time I didn't have a large enough pot so I split the wort in to two pots on the stove and lost 2.5 gallons over an hour (and had a steamed up cupboard of glasses to prove it!). This time I am boiling it in one pot on a propane burner. I would be fine to start with 8 gallons and if I end up with a little more than 6, that's fine because I have an 8.5 gallon bucket for my primary and a 6.5 gallon carboy for conditioning.

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I have been having good luck mashing at whatever temp the recipe calls for. I then batch sparge twice at about 170 degrees. 1.1 seems to be a pretty good ratio to start out with. If I were you, if you're using a 5 gallon recipie, shoot for 6.5 gallons to boil and try to end up with 5.5 gallons for the primary. Then when you rack to secondary, keg or bottles you'll come pretty close to 5 gallons. If you end up with 6.5 gallons when using a 5 gallon recipe you may have problems with your gravity readings and possibly fermentation if you don't pitch enough yeast. Not to mention your hops percentages will be off from what the recipe is shooting for.

Yooper said:

If you're batch sparging, I'd suggest dropping the mash out and just adding that volume to the sparge water. Do two equal batch sparges, and no mashout, after the mash.

I almost always mash at 1.33 to 1.5 quarts of water per pound of grain. There are a couple of reasons- one is pH. The other is that if you do that, when you figure out the water volumes, you'll find that you get out 1/3 of the runnings from the mash, 1/3 from the first sparge, and 1/3 from the second sparge. That's about perfect in dealing with volumes and pH for me.

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Ok I can see the logic in that. Thanks!

So for example under the 1.25 ratio, I mash with ~5gallons, run-off ~3gallons, then sparge twice with ~2.5 gallons each to get ~8 gallons total.

And so after my first run-off, the volume left in my mash tun (~2 gallons) will be pretty close to the volume of sparge water I'm adding. So I heat the water such that the average temperature between the 2 is 170F?

Brewed this yesterday and the batch sparge went so smooth! Skipped the mash-out and sparged with boiling water twice. Ended up with a 73% efficiency and had a great time brewing with a friend.

I reached 66% with my previous fly-sparge (which I did poorly) attempt but it was way more stressful with my space/equipment.

Looking back I can think of a couple more ways to reduce losses and get that number up past 75% next time.

Thanks again for the help.