Does your mash and sparge water need to be at the same volume?

While making a 13 lb grain bill yesterday, my mash calculator determined that I would need approx. 4.75 gallons of water for the mash. In previous batches with less grain, I have been able to keep the mash volume and the sparge volume in equal parts.

So calculating my mash water went something like this.
1.5 quarts * 13 in gallons (type this into Google and will do the math for you)

Results: 1.5 US quarts * 13 = 4.87500 US gallons

I know that I could drop down to 1.2 US quarts but I would still end up with 3.9 gallons of mash water which exceeds the size of my kettle if I sparge with an equal amount of H2O.

My kettle which can only hold 7.5 gallons of total volume, but let's call it 7 gallons because I need some headspace in the kettle for a rolling boil. (Even that is snug, I prefer a full gallon of head space.)

Based on my kettle am I limited to only make 10lb-11lb grain bills? and only left with DME,etc.. to raise my gravity? If I want to make higher alcohol content based beers do I need a 10 gal kettle?


Thanks,
jlanier01

If you don't want to drop any efficiency points, then yes you're limited.

If you don't mind dropping 5% on the efficiency, just squeeze down to 1.2 quarts/kg and unequal volumes. That's what I do (sounds like I have similar kit to you) and then I'm limited by the mash tun around 14lb. Beyond that I go for extract/DME. I normally to 5.5gal batches and start adding extract/DME on gravities above 65ish

I think Mark meant 1.2 quarts/lb not Kg.
The mash water does not have to be equal in volume to the sparge water. I usually mash using 1 qt / lb and sparge until I reach the required volume or my gravity drops to 1.010 (whichever comes first). This means I use nearly twice as much sparge water as mash water.
It isn't really the size of the kettle that is limiting your gravity. If I use 14 lb grain in a batch, I still collect the normal 7 gallons, but to do that and still get good efficiency, I need to mash thicker than you do, and use more sparge water to rinse the sugars out of the grains.

-a.

ajf said:

I think Mark meant 1.2 quarts/lb not Kg.
The mash water does not have to be equal in volume to the sparge water. I usually mash using 1 qt / lb and sparge until I reach the required volume or my gravity drops to 1.010 (whichever comes first). This means I use nearly twice as much sparge water as mash water.
It isn't really the size of the kettle that is limiting your gravity. If I use 14 lb grain in a batch, I still collect the normal 7 gallons, but to do that and still get good efficiency, I need to mash thicker than you do, and use more sparge water to rinse the sugars out of the grains.

-a.

Click to expand...

So are you not too concerned about how much sparge water to heat up? Just add a couple gallons, run-off until you hit your volume.

I guess I was worried I might leave a lot of sugar in the grain bed if I rinse with a large volume of water. Are you usually dumping a wet grain bed with a lot of sugar remaining?

markcurling said:

If you don't want to drop any efficiency points, then yes you're limited.

If you don't mind dropping 5% on the efficiency, just squeeze down to 1.2 quarts/kg and unequal volumes. That's what I do (sounds like I have similar kit to you) and then I'm limited by the mash tun around 14lb. Beyond that I go for extract/DME. I normally to 5.5gal batches and start adding extract/DME on gravities above 65ish

Click to expand...

Thanks Mark, my mash tun is a 10 gal rubbermaid cooler. I'm realizing the limitations of my setup and sounds like there are some workarounds.

Thanks for the correction, my brain struggles to think outside of metric!

Are we talking about fly sparging here?

I find i get slightly better efficiency if I calculate how much sparge water to use, run it all through and get the correct volume. However, sometimes when I use too much I have to turn the tap off while there is water left in the grain bed - the efficiency loss is very minimal.

I normally run at 70% - I don't care how high that is, just that I am able to get it within 2% each time now so I know how to construct recipes to hit my gravities!

The correlation you're thinking about is keeping the runoffs of batch sparging as equal as possible, no mash water and sparge water. It would actually require more mash water than sparge because you have to account for the amount of wort that is absorbed by the grain.

In the case of fly sparging, you'd just stick with your preferred ratio for the mash (1.25 to 2qt/lb is typical) and just keep sparging and running off until you get your desired volume.

jlanier01 said:

So are you not too concerned about how much sparge water to heat up? Just add a couple gallons, run-off until you hit your volume.

I guess I was worried I might leave a lot of sugar in the grain bed if I rinse with a large volume of water. Are you usually dumping a wet grain bed with a lot of sugar remaining?

Click to expand...

For a typical (for me) brew, I use about 10 lbs grain and 2.5 gallons strike water for the mash. At the end of the mash, I add about 5 qt boiling water for a mash out, and then I fly sparge. If I had no dead space, I would need about 4.5 gallons of sparge water to hit my pre-boil volume. But I lose about 1/2 gallon to dead space, so I need to prepare at least 5 gallons. I fly sparge, and like to stop the sparge when the gravity of the runnings drops to 1.010, and with a 10 lb grain bill, this usually occurs about 1 gallon shy of my required pre-boil volume. When that happens, I stop the sparge and make up the volume by pouring the sparge water directly from the HLT to the kettle, which leaves a large amount of water in the MLT. I find that I need about 6.5 gallons of sparge water to account for this.
With a grain bill of 14 lbs, I can sparge until I reach my pre-boil volume without having to worry about the gravity of the runnings dropping too low, so I prepare less sparge water (14 qt for mash in, 7 qt for mash out, 2 qt for dead space, and 4 gals for sparge). I usually prepare about 5 gals for the sparge just in case something goes wrong. Over 14 lbs, I would start to lose efficiency, but that doesn't worry me because I don't like very strong beers.
At the end of the sparge, there is very little sugar left in the grain, and I get 85% efficiency now I've gotten used to the MLT (the same one you have).
If I used less sparge water, then I would start to lose efficiency and leave more sugars in the grains with a grain bill of less than 14 lbs.

-a.

Sure, though you have to take all the rules with a pinch of salt - if I'm running a big grain bill and fly sparging, I'm sure I gain efficiency by shorting the mash ratio so I'm not left with only half a gallon to sparge with!

On big beers, using my 5-gal cooler, my process is similar to AJF's in that I mash pretty thick and fly sparge. (I max out around 1.090 post-boil with it). However, I don't do a mash-out.

I heat the liquor to about 180-185°F and use that as sparge water. It brings up the grain to mashout temp while fly sparging. However, I'd like to keep the grain around 170°F when sparging, which means after the grain's at 170°F, we don't want to add any more heat.

Thankfully, my stainless stockpot HLT loses heat to surrounding air at about the rate that the grain is approaching 170°. That is, about halfway through the sparge, the HLT's at 170° or so, so the grain doesn't go much above 170°F... Make sense?

_JP_ said:

On big beers, using my 5-gal cooler, my process is similar to AJF's in that I mash pretty thick and fly sparge. (I max out around 1.090 post-boil with it). However, I don't do a mash-out.

I heat the liquor to about 180-185°F and use that as sparge water. It brings up the grain to mashout temp while fly sparging. However, I'd like to keep the grain around 170°F when sparging, which means after the grain's at 170°F, we don't want to add any more heat.

Thankfully, my stainless stockpot HLT loses heat to surrounding air at about the rate that the grain is approaching 170°. That is, about halfway through the sparge, the HLT's at 170° or so, so the grain doesn't go much above 170°F... Make sense?

Click to expand...

Haha yes I do exactly that, I love it when laziness makes perfect logic sense!

_JP_ said:

On big beers, using my 5-gal cooler, my process is similar to AJF's in that I mash pretty thick and fly sparge. (I max out around 1.090 post-boil with it). However, I don't do a mash-out.

I heat the liquor to about 180-185°F and use that as sparge water. It brings up the grain to mashout temp while fly sparging. However, I'd like to keep the grain around 170°F when sparging, which means after the grain's at 170°F, we don't want to add any more heat.

Thankfully, my stainless stockpot HLT loses heat to surrounding air at about the rate that the grain is approaching 170°. That is, about halfway through the sparge, the HLT's at 170° or so, so the grain doesn't go much above 170°F... Make sense?

Click to expand...

What is your max grain bill when working with this cooler? Also the kettle size and the amount of water that you are mashing and sparging with? Thanks!