Using too much Mash water
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pricelessbrewing
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You'd likely gain some effeciency, but at a steep cost imo. You'd have to add quite a bit of acid to keep your mash ph in range. Adding too much strike water might eventually risk tannins similarly to oversparging but not sure at what point that would happen..
You'd have to boil off for an extra couple hours depending on your setup to get down to the proper preboi volume.
You'd have to boil off for an extra couple hours depending on your setup to get down to the proper preboi volume.
I ran a Bru'nWater calc on 10 lbs 2-row with 10 gal of strike water for a 5.5 (to fermenter) batch. Starting with RO water and adding 2.5 g gypsum, 2.0 g Mg sulfate, 4.0 g CaCl, and 5.5 ml 88% lactic acid, produced a projected mash pH of 5.36.
So, acid addition doesn't seem excessive.
The biggest issue will be boiling off the excess water (as priceless said). At a 1.2 gal/hr boil off rate, you would be looking at a 3 hr boil (using priceless' calculator.)
Edit: Forgot to note that if you start with high alkalinity water, you will need lots more acid to bring the mash pH down.
Brew on
So, acid addition doesn't seem excessive.
The biggest issue will be boiling off the excess water (as priceless said). At a 1.2 gal/hr boil off rate, you would be looking at a 3 hr boil (using priceless' calculator.)
Edit: Forgot to note that if you start with high alkalinity water, you will need lots more acid to bring the mash pH down.
Brew on
pricelessbrewing
Brewer's Friend Software Manager
I ran a Bru'nWater calc on 10 lbs 2-row with 10 gal of strike water for a 5.5 (to fermenter) batch. Starting with RO water and adding 2.5 g gypsum, 2.0 g Mg sulfate, 4.0 g CaCl, and 5.5 ml 88% lactic acid, produced a projected mash pH of 5.36.
View attachment 301250
So, acid addition doesn't seem excessive.
The biggest issue will be boiling off the excess water (as priceless said). At a 1.2 gal/hr boil off rate, you would be looking at a 3 hr boil (using priceless' calculator.)
Brew on
interesting idea. Instead of adjusting your mash ph by adding acid, could you just add additional strike water or mash thicker.
Bellybuster
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Hmmmmm, BIAB
It's a lot of water even for BIAB. Using 10 lbs of grain with 1.2 gal/hr boil off and 0.08 gal/lb absorption to get 5.5 gal into fermenter, a full volume mash only requires 7.6 gal of strike water.
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Bellybuster
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yes it is but...
why anyone would even have a reason to mash a gallon per pound I have no idea
why anyone would even have a reason to mash a gallon per pound I have no idea
I ran a Bru'nWater calc on 10 lbs 2-row with 10 gal of strike water for a 5.5 (to fermenter) batch. Starting with RO water and adding 2.5 g gypsum, 2.0 g Mg sulfate, 4.0 g CaCl, and 5.5 ml 88% lactic acid, produced a projected mash pH of 5.36.
View attachment 301250
So, acid addition doesn't seem excessive.
The biggest issue will be boiling off the excess water (as priceless said). At a 1.2 gal/hr boil off rate, you would be looking at a 3 hr boil (using priceless' calculator.)
Edit: Forgot to note that if you start with high alkalinity water, you will need lots more acid to bring the mash pH down.
Brew on
Ok, ran this calc again using hard water (171 ppm total alkalinity, 120 ppm RA.)
So, now it takes 15 ml of lactic acid to get to the same 5.36 projected mash pH.
Brew on
I wasn't planning to use a gallon per pound but I mentioned it just to serve as an example. So it looks like the primary reason for not going more than 1.5 quarts per lb of grain is to avoid having to boil off a lot of water.
Oh. Yes, 4 qts/lb would be crazy thin. Taking the ratio that high wouldn't be wise. However, you could work with something up to around 2 qts/lb and that should be feasible. I routinely target between 1.5 and 1.75 qts/lb when I brew with my RIMS.
For full volume (no sparge) mashing (typical of BIAB), ratios of 3.0 - 3.25 qt/lb (or a little higher) are not unusual. No reason to go much higher than that. Good results are still obtained.
Brew on
MannyEdwards
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I believe the problem with a very thin mash is that the concentration of enzymes and other reagents gets too low, and they don't their job of conversion as well, so you actually have less efficiency.
That's the theory but in practice it takes a very thin mash before that becomes a problem. My efficiency didn't seem to change for a mash at 4qts/lb. Most people would never want to go that thin.
MannyEdwards
Well-Known Member
Good to know. One more factor I can eliminate in my quest for better efficiency. Thanks!
That theory has been refuted with experimental evidence (http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness.)
The problem with the theory is that it takes into account only one factor (enzyme concentration), but ignores what turns out to be a more important factor which is molecular mobility. The molecular mobility has a greater effect on saccharification rate than does enzyme concentration.
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MannyEdwards
Well-Known Member
That theory has been refuted with experimental evidence (http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness.)
The problem with the theory is that it takes into account only one factor (enzyme concentration), but ignores what turns out to be a more important factor which is molecular mobility. The molecular mobility has a greater effect on saccharification rate than does enzyme concentration.
Brew on
Interesting. So do you get essentially the same results whether using 1 qt/lb or 2?
MannyEdwards
Well-Known Member
That theory has been refuted with experimental evidence (http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness.)
The problem with the theory is that it takes into account only one factor (enzyme concentration), but ignores what turns out to be a more important factor which is molecular mobility. The molecular mobility has a greater effect on saccharification rate than does enzyme concentration.
Brew on
Interesting. So do you get essentially the same results whether using 1 qt / lb or 2?
And any savings you may get from a tiny bit of extra efficiency will be thrown out the door with all the extra gas you will need to boil off the extra water.
Makes sense!
At 2 qt/lb you usually get faster conversion than at 1 qt/lb (this was Kai's result.) Faster conversion gives you a better chance of getting complete, or at least more, conversion in your alloted mash time.
Brew on
Not an issue. You shouldn't be using more water than needed to achieve your target pre-boil volume, so you shouldn't have any extra water to boil off. If you do end up with excess water, you've done something wrong.
12.5 lbs of grain for a pre-boil volume of 6.7 gal with a grain absorption of 0.12 gal/lb and no sparge gives you a mash water to grain ratio of:
4 qt/gal * (6.7 gal + 12.5 lb * 0.12 gal/lb) / 12.5 lb = 2.624 qt/lb
If you were doing a lower OG beer or a beer requiring a 90 minute boil, then you water to grain ratio would be even higher.Brew on
MannyEdwards
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At 2 qt/lb you usually get faster conversion than at 1 qt/lb (this was Kai's result.) Faster conversion gives you a better chance of getting complete, or at least more, conversion in your alloted mash time.
Brew on
Thanks, glad I asked. I'm brewing today, and going to give it a shot. My efficiency needs improving. The larger volume of water will help keep a more even temp in the mash tun -- nice bonus.
Yes it will. I'll have to remember to include that with the list of "pros" for thinner mashes. Thx for bringing it up.
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MannyEdwards
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I had my efficiency set at 65% on Brewers Friend and nailed it. I know it's not that great, but it's pretty good for me. I have no doubt the extra volume and steadier temp helped.
Since it seems like there is nothing negative with using a lot of water in the mash besides having to boil all that water off, I will use three or four gallons of water for my partial mash recipe that uses only 4 lbs of grain.
I'm not aware of any data using more than 1 gal/lb (4 qt/lb.) You would be in uncharted territory. You will definitely need to be very careful with mash pH (to avoid tannins), and you may be past the point where more water improves conversion rate (there's no guarantee that the "more is better" extends into the range you are talking about.)
Brew on
MannyEdwards
Well-Known Member
I've done two batches now with 2 qt/lb and about 3 stirs during the hour. I did note that the temperature of the thinner mash seems to stratify -- the thermometer drops a little, but the temp rises again when it's stirred. It's about a one degree difference, so no big deal, but I suspect that if it were much thinner the fluctuations would increase.
Temperature stratification indicates you are losing much more heat from one part of the mash tun (probably the top) vs. other parts. The mash will be cooler near where the heat loss is greatest.
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bigdongsr94
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Didn't respond as I thought the first 20some had taken care of it but I guess not. I would never add a gallon per pound, never again anyway. I started brewing with full volume biab. I would have about a pound per gallon and ended very tannic due to pH. Many dumped batches based on the fact that "many people do it" on the web. Maybe but it doesn't work for me. I have good water but using all light grains there wasn't enough acidity.
Adjusting the water chemistry to keep the mash pH in an acceptable range is even more important with thin mashes. Proper mash (and sparge) pH adjustment will avoid tannin extraction (and the resulting astringency.)
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chickypad
lupulin shift victim
Not trying to be a jerk, but it seems like this whole thread is about pH being the primary issue with very thin mashes and the fact that you'll likely have to add some acid.
QuadConPana
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FYI.
I came to this thread because my false bottom is quite tall and leaves almost 10 quarts of dead space under the grain bed. Since I don't have an unlimited supply of kegs, I can't always do a 10 gallon batch. So at 1.25 quarts per gallon, 12 pounds of grain would be sitting in 5 quarts of water. At 2.5 per, the grain would have 20 quarts to move around in. And, that would pretty close to the amount of wort I would want to start my boil with.
So, as for the "why would you want to?" question, that's one reason.
I came to this thread because my false bottom is quite tall and leaves almost 10 quarts of dead space under the grain bed. Since I don't have an unlimited supply of kegs, I can't always do a 10 gallon batch. So at 1.25 quarts per gallon, 12 pounds of grain would be sitting in 5 quarts of water. At 2.5 per, the grain would have 20 quarts to move around in. And, that would pretty close to the amount of wort I would want to start my boil with.
So, as for the "why would you want to?" question, that's one reason.
