Mash and sparge volume question

When mashing does the first volume of water you use suppose to be more or less then the amount of sparge water you use? I am trying to have 7.5 gallons pre boil.

This is what I have for my current recipe:

15lb total grain

15x1.5=22.5 qtrs of water % 4 = about 5.62 gal water for the mash

15x.125 (grain absorption) = 1.875 gal of water absorbed by grains

5.62-1.875=about 3.75 gals of wort from mash.

So 7.5-3.75=3.75 gal of water to sparge with.

Does this look correct? I thought I read somewhere that your sparge amount should be higher then the initial mash amount when it comes to water volume. Please let me know if that is incorrect.

These look pretty good...my only change if this was my calc would be that I normally assume .1 per lb grain absorption instead of your .125. Very minor difference though.

That's exactly how I do it, too. You may have heard that about sparge being higher than the initial volume, which could be related to a wort quality/optimization thing, but when sparging, IMHO the most important thing is making your target pre-boil volume.

This brings up another question about the amount of water needed...Say I use the calculated mash and sparge but I run short on my pre-boil volume, do I add more sparge water to my MLT? Could I just add extra water to the initial sparge water and stop once I hit my pre-boil or would I just be losing efficency?

riverfrontbrewer said:

These look pretty good...my only change if this was my calc would be that I normally assume .1 per lb grain absorption instead of your .125. Very minor difference though.

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Thanks. Doing .125 has been having me constantly hitting my volumes so I will stick to that.

cactusgarrett said:

That's exactly how I do it, too. You may have heard that about sparge being higher than the initial volume, which could be related to a wort quality/optimization thing, but when sparging, IMHO the most important thing is making your target pre-boil volume.

Click to expand...

Well I am glad I am doing it the correct way. :rockin:

CaptKiRkLeS said:

This brings up another question about the amount of water needed...Say I use the calculated mash and sparge but I run short on my pre-boil volume, do I add more sparge water to my MLT? Could I just add extra water to the initial sparge water and stop once I hit my pre-boil or would I just be losing efficency?

Click to expand...

I would think putting it in the MLT wouldn't lose efficiency. I have heard of people added water directly to their fermenter to reach their volume but I could be wrong.

CaptKiRkLeS said:

This brings up another question about the amount of water needed...Say I use the calculated mash and sparge but I run short on my pre-boil volume, do I add more sparge water to my MLT? Could I just add extra water to the initial sparge water and stop once I hit my pre-boil or would I just be losing efficency?

Click to expand...

Adding more water than you need is going to reduce your efficiency unless you increase your boil to compensate.

You have a set amount of sugars in your grain that you are going to get out during the sparge.

Lets say you want 7.5 gallons total volume, and you have 4.5 from your mash.

If you use the correct amount of sparge water, 3 gallons assume you get runnings at 1.040 gravity. If you used 3.5 gallons under the same conditions then you would get your runnings at (1.04*3=C*3.5) 1.034 which would lower the total gravity of your boil, and thus the gravity going into the fermenter UNLESS you boiled off that extra half gallon.

I always heat up more sparge water than I think that I'll need, but I'm sure to measure the first runnings of the mash so that I can get an accurate pre-boil volume before I start sparging. If you run short, then you can just do a small second sparge.

IPAAAA said:

When mashing does the first volume of water you use suppose to be more or less then the amount of sparge water you use? I am trying to have 7.5 gallons pre boil.

This is what I have for my current recipe:

15lb total grain

15x1.5=22.5 qtrs of water % 4 = about 5.62 gal water for the mash

15x.125 (grain absorption) = 1.875 gal of water absorbed by grains

5.62-1.875=about 3.75 gals of wort from mash.

So 7.5-3.75=3.75 gal of water to sparge with.

Does this look correct? I thought I read somewhere that your sparge amount should be higher then the initial mash amount when it comes to water volume. Please let me know if that is incorrect.

Click to expand...

Have you accounted for dead space in the MLT? Depending on the design of your MLT you could end up just a bit short of your pre-boil volume if you do not account for the dead space.

Never had an issue with dead space. I always end up pulling the MLT towards me to try and get every little last bit out.

Aha..gotcha. I am still working on getting my numbers down. So I will see how it turns out this weekend.