Author Topic: Water to grain ratio for mash tun.  (Read 22365 times)

Offline hopfenundmalz

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Re: Water to grain ratio for mash tun.
« Reply #30 on: March 15, 2011, 08:05:04 PM »
Would a nice cream stout be too ambitious for a first all grain?
For a dark beer, you may have to deal with water issues.  If you're prepared to deal with that, go for it.  Otherwise, something middle of the road like a pale ale may be a better choice.
My water is definitely hard which is good for dark beers, correct? Any other water issues I should be worried about?
Yes...typically "hard water" is good for brewing dark beers.
It is more correct to say "alkaline" water is good for brewing dark beers.
 
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Offline malzig

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Re: Water to grain ratio for mash tun.
« Reply #31 on: March 16, 2011, 03:44:37 AM »
What's the downside to going above ~2 qts lb?  pH?
I'd think you'd also be driving the enzyme concentration too low
The enzyme concentration might be a bit lower but the enzymes probably have been access to the starches in a thinner mash.
Right, enzyme concentration is probably rarely the limiting factor for most mashes.  Starch gelatization more apt to be limiting.  A thinner mash probably improves starch gelatinization.
From my experience, anything 1.25-1.75qt/lb is the sweet spot (no pun intended) for the best mash efficiency.
Did you actually have problems above 1.75 qts/#?  I never have.

Offline bluesman

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Re: Water to grain ratio for mash tun.
« Reply #32 on: March 16, 2011, 06:19:18 AM »
From my experience, anything 1.25-1.75qt/lb is the sweet spot (no pun intended) for the best mash efficiency.
Did you actually have problems above 1.75 qts/#?  I never have.

I've mashed a few batches around the 2.0-2.3 range in the past with mixed results that I can't definitively point one way or the other to efficiency related issues. However there are some published experiments., I believe Kai can comment on the exact data that reflects some loss of efficiency with W:G ratios above 2.0.

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Offline bluesman

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Re: Water to grain ratio for mash tun.
« Reply #33 on: March 16, 2011, 06:48:48 AM »
I know this will eventually get Kai's attention. The following was taken from braukaiser.com. This experiment was conducted by Kai.

The chart gives the expected first wort extract/gravity based on the mash thickness at the time that the sample is pulled. To simplify the calculations this table assumes an 80% potential extract content in the grist (which is typical for most base malts) and 100% mash efficiency. Use these numbers as a benchmark for comparing your measured first wort gravities.
 



I think that thinner mashes aid in better extraction of soluble sugars but I also remember reading about a thickness cutoff where there are diminishing returns.
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Offline tomsawyer

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Re: Water to grain ratio for mash tun.
« Reply #34 on: March 16, 2011, 10:26:38 AM »
I guess you could take 0.5qt/lb of grain as your bound water, subtract that from the mash ratio, then multiply by the SG points to get your overall efficiency.  Otherwise its hard to see what the effect of increasing the mash water is.
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Offline tygo

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Re: Water to grain ratio for mash tun.
« Reply #35 on: March 16, 2011, 11:18:10 AM »
I think that thinner mashes aid in better extraction of soluble sugars but I also remember reading about a thickness cutoff where there are diminishing returns.

I'm sure there are diminishing returns.  You can only go so high on the efficiency.  But I don't see how decreasing the thickness could decrease your efficiency.  In my experience it's always been in the opposite direction but I haven't taken it to any extremes to see.
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Offline bluesman

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Re: Water to grain ratio for mash tun.
« Reply #36 on: March 16, 2011, 11:35:48 AM »
I think that thinner mashes aid in better extraction of soluble sugars but I also remember reading about a thickness cutoff where there are diminishing returns.

I'm sure there are diminishing returns.  You can only go so high on the efficiency.  But I don't see how decreasing the thickness could decrease your efficiency.  In my experience it's always been in the opposite direction but I haven't taken it to any extremes to see.

My wording is a little misleading here. There is certainly diminishing returns and the mash efficiency can be impacted by conversion. Practically speaking, mash pH is about the only thing I can think of that would impact the efficiency of a very thin mash. If there is a very large ratio of water to grain that would prevent the pH from adjusting to the targeted zone it could be detrimental to conversion.
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Offline redbeerman

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Re: Water to grain ratio for mash tun.
« Reply #37 on: March 16, 2011, 11:42:50 AM »
Dilution of enzymes may be a side effect of a thinner mash, thus decreasing efficiency as well.
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Offline hokerer

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Re: Water to grain ratio for mash tun.
« Reply #38 on: March 16, 2011, 11:46:51 AM »
Dilution of enzymes may be a side effect of a thinner mash, thus decreasing efficiency as well.

...sounds familiar :)...

I'd think you'd also be driving the enzyme concentration too low

...although the responses were pretty generally against that as an issue.
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Re: Water to grain ratio for mash tun.
« Reply #39 on: March 16, 2011, 12:01:39 PM »
I don't recall going much above 2 qt./lb. but I didn't see any problems at that point that would indicate that the enzymes were too diluted.
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Offline wuertele

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Is mash thickness calculated to include dead space?
« Reply #40 on: March 16, 2011, 12:35:17 PM »
My MLT has a false bottom, and I have quite a bit of wort in the recirculation plumbing at any given time.  In fact, I have wort sitting about an inch above the grain bed that doesn't contact the mash until it drains into it.

When I calculate mash thickness, should I include *all* my wort (i.e. the volume of my strike water), or just the wort that is in contact with the grains?

If it is just the wort in contact with the grains, I would have to subtract out 2 gallons from my false bottom, a gallon or more for my plumbing, and about a gallon for the wort abobve the top surface of the grain.
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Offline tomsawyer

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Re: Water to grain ratio for mash tun.
« Reply #41 on: March 16, 2011, 01:38:49 PM »
I guess you could take 0.5qt/lb of grain as your bound water, subtract that from the mash ratio, then multiply by the SG points to get your overall efficiency.  Otherwise its hard to see what the effect of increasing the mash water is.

I started to do the math and realized it'd be more accurate to judge the conversion by multiplying the qt/lb number by the first runnings points.  If you do that you see a slight increase in the total points converted over the range of 1qt/lb through 3.35qt/lb.  So there is obviously no decrease in conversion due to a thin mash and/or diluted enzymes.  Its another matter how much you can run off versus the volume left to sparge with, I think we can still assume that euqal runnings is something to shoot for there.  But for someone like me who is giving no-sparge a try, its comforting to know that I can add more water to the mash if I want.

For the record, 1.05 qt/lb gives 116 pts, and 3.35qt/lb gives 134 pts.
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Offline Kaiser

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Re: Water to grain ratio for mash tun.
« Reply #42 on: March 16, 2011, 02:27:17 PM »
I’ve been pretty busy and ran into this thread only now. Since I have done my fair amount of thinkering with different mash thicknesses, let me chime in.

Mash thickness and efficiency:

Based on my observations, thin mashed can convert faster and more complete compared to thick mashes. But that will only show up a difference when the thick mash didn’t achieve close to 100% conversion efficiency.

If the conversion efficiency between both mashes is the same a thin mash will have a better efficiency into the BK due to the larger amount of sparge water available in thick mashes. But that gain in efficiency is not necessarily good for beer quality.

Enzyme dilution:

The BIAB brewers have shown us that even in very dilute mashes the enzymes are not too diluted. You have to keep in mind the enzymes can also be inhibited by too much substrate or product (substrate inhibition) because their active sites get too crowded.

pH
mash pH is a function of distilled water pH of the grist, residual water alkalinity and mash thickness. In its simplest form it can be written as:

mash_pH = grist_pH + B*RA*R

(acid additions are reflected in the residual alkalinity for simplicity)
where B is a constant, RA is the residual alkalinity of the water and R is the mash thickness. You’ll notice that doubling R doubles the increase in mash pH over the distilled water pH of the grist, and you may be tempted to compensate a high RA with a low R (thick mash), but any water that you are not using in the mash you’ll be using during the sparge where it raises your sparge an then the boil pH too much. In the end you see that alkalinity is the problem and not mash thickness.

Personally I like using thin mashes where I use about 50-60% of the total water in the mash and the rest for sparging.

Kai

Offline richardt

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Re: Water to grain ratio for mash tun.
« Reply #43 on: March 16, 2011, 03:19:36 PM »
Like KGS, I tend to fill my 10 gallon round Rubbermaid cooler with the grist, and then add the water.

Doing it the other way (i.e., adding the grist to the water in the cooler) raises two concerns for me:
1.)  I may not be able to get all the grist in the 10 gallon cooler

I tend to brew high-gravity brews and/or 10 gallon batches, so it is not unusual to see 7 or 8 gallons of dry grist filling the cooler before the water is added.

2.)  More enzyme damage may occur if I add the initial amounts of grist to the entire mash volume of hot water.

High initial "strike" temp of water in the mash cooler could have a disproportionate effect on the first addition of grist and lead to enzyme denaturation.  On the other hand, a quicker drop in strike water temp should occur if strike water is added to the entire amount of grist, and less damage occurs to the enzymes.

What say you?

Offline Will's Swill

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Re: Water to grain ratio for mash tun.
« Reply #44 on: March 16, 2011, 05:08:38 PM »
I'd say that you'd not see much enzyme damage because you won't remain at high temp all that long even when adding grist to water.


If the conversion efficiency between both mashes is the same a thin mash will have a better efficiency into the BK due to the larger amount of sparge water available in thick mashes.


Was this a typo?  I would think that more sparge water would lead to higher efficiency so that if you see any effect at all it would be that thicker mashes are more efficient.  Or am I missing a secondary effect here?
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