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General Category => All Grain Brewing => Topic started by: NorthernIke on January 24, 2010, 04:13:08 PM

Title: Do Finely Milled Grains Retain Less Water?
Post by: NorthernIke on January 24, 2010, 04:13:08 PM
I've recently been milling my grains on the tightest mill setting.  I think my gap is about .028".  I condition grains and get beautifully intact hulls, with a lot of fine grits.

On my last several batches I've noticed that I am getting a lot more wort from my standard water additions.  For instance, this morning I used 9.1 gallons total water, and ran off 8.25 gallons of wort.

11 LBS of grain is only retaining .85 gallons of water.  This is much less than I've experienced in the past.

Does anyone have similar experience?  I think in the past, I'd figure on at least 1 - 1.5 gallon of lost wort per 10 LBS of grain.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 24, 2010, 04:30:35 PM
Maybe it's due to the conditioning?  If the grain is already damp, maybe it absorbs less?  Just a WAG....
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: NorthernIke on January 24, 2010, 04:39:21 PM
Denny - You mill really finely too.  What is your usual value for wort loss due to absorption?
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 24, 2010, 05:46:12 PM
I'd have to check my notes to be sure, but IIRC somewhere around .12 gal./lb.  I just mashed in, so in about an hour and a half I'll have real numbers.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 24, 2010, 08:13:33 PM
OK, I just finished my sparge.  9.75 gal. in, 8.3 gal. out, 11.63 lb. of grain.  That makes it .124 gal./lb. absorption.

BTW, according to Promash, I got 96% efficiency!   ;D ???
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: a10t2 on January 24, 2010, 08:33:58 PM
BTW, according to Promash, I got 96% efficiency!   ;D ???

So you finally upgraded to fly sparging, eh? ;)
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: tygo on January 24, 2010, 09:18:34 PM
OK, I just finished my sparge.  9.75 gal. in, 8.3 gal. out, 11.63 lb. of grain.  That makes it .124 gal./lb. absorption.

BTW, according to Promash, I got 96% efficiency!   ;D ???

Is that the Best Malz malt again that you posted about a while ago?
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: Kaiser on January 24, 2010, 10:07:37 PM
I noticed that grain absorption can change even from malt to malt.

Kai
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 24, 2010, 11:02:55 PM
Yeah, it's Best pils and Best Munich II.  I can't help but feel there's something wrong with the way I have Promash set up.  I'll start another thread later with the numbers and maybe the brain trust here can help me figure out what's going on.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: dbeechum on January 25, 2010, 07:51:16 AM
Must be Super Fly sparging.

I need the bass line and Curtis Mayfield as evidence please.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 25, 2010, 04:16:50 PM
Doing the math myself, I think it's somewhere closer to 80%.  Much more reasonable.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: Kaiser on January 25, 2010, 04:25:15 PM
Doing the math myself, I think it's somewhere closer to 80%.  Much more reasonable.

Did you put the number in my spreadsheet? You don't have to enter everything. Just grain weight, extract potential, wort volume and gravity are enough to give you an efficiency number.

Kai
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 25, 2010, 04:28:31 PM
I haven't yet, but I certainly intend to....the big mystery to me is the extract potential for this malt.  I'm guessing 37 or 38 ppg, but I don't know for certain.

EDIT:  OK, doing that I get about 92% mash efficiency and about 79% into the fermenter.  That sounds correct.  I formulated the recipe at 73% for 5.5 gal. at 1.054 and got 6 gal. at 1.057.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: Kaiser on January 25, 2010, 04:41:05 PM
I haven't yet, but I certainly intend to....the big mystery to me is the extract potential for this malt.  I'm guessing 37 or 38 ppg, but I don't know for certain.

You might be better off entering the extract potential as % along with a realisic moisture content (e.g. 4%). This removes some ambiguity about the % to ppg conversion.

Keep in mind, however, that you should use the same efficiency calcuation procedure for both recipe design and brewday evaluation. By doing so you'll make the same errors in both places and it doesn't matter to your brewing. Only when we start evaluating what the actual efficiency was, especially once you get that close to 100%, is it important to be correct with the efficiency calculation.

Kai
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 25, 2010, 04:50:21 PM
I entered 85% since someone had mentioned that number previously when I asked about Best malts.  I left the moisture setting at default.  As to procedure, since I was using Promash both to formulate the recipe and to track the brewday, I assumed (yeah, I know!) that it would be consistent.  I need to figure out what's going on when I use the brewing session part of Promash that gives me such a radically different number.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: a10t2 on January 26, 2010, 01:43:42 AM
85% is *very* high. I don't think I've ever seen an analysis over 83%.
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: Kaiser on January 26, 2010, 03:11:27 AM
85% is *very* high. I don't think I've ever seen an analysis over 83%.

that's what I thought too. Babalu just recently send me analysis sheets from a North Country Malt and the FGDB is generally around 82%.

Kai
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 26, 2010, 04:40:13 PM
You guys are correct.  My memory was wrong...wow, imagine that!  Blatz reported in the other thread that his last order was 81.2%.  I'll get the figures re-entered and see what happens.

And I've gotta ask....81.2% of what?  what does that figure mean?
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: Kaiser on January 26, 2010, 04:56:10 PM
And I've gotta ask....81.2% of what?  what does that figure mean?

81.2 % of the dry weight. The dry weight is the weight of the malt w/o the weight of the moisture. I.e. malt weight multiplied with (100% - MC). MC is moisture content and generally between 3 and 5%. Your 81.2% of dry weight are 81.2% * 0.96 = 77.652% of the actual malt weight if the MC is 4%. That's why I have an field for both the extract potential and the moisture content in my spread sheet.

Kai
Title: Re: Do Finely Milled Grains Retain Less Water?
Post by: denny on January 26, 2010, 05:19:25 PM
Thanks (again) for the explanation, Kai.