Author Topic: Mash Efficiency Problem  (Read 11765 times)

Offline kramerog

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Re: Mash Efficiency Problem
« Reply #120 on: September 16, 2013, 11:13:40 AM »
I usually loose 1 degree F during a 1 hour mash for a 10-gal mash after the water and grains are thoroughly mixed.  Your 6 F temp loss is not normal unless you left the lid off the mash tun for 1 hour.

However, I heat up my strike water 6-8 F hotter than what I calculate which compensates for evaporation and cooling during the water transfer and mixing, and heating the mash tun.
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Offline denny

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Re: Mash Efficiency Problem
« Reply #121 on: September 16, 2013, 11:15:09 AM »
So I brewed and I think I figured out the problem. I still had an efficiency problem, though not quite as bad, did have double crush and it improved but not by a ton.

I use a 10 gallon round rubbermaid mash ton, and I am brewing 5-gallon batches so I am getting about 7.3 gallons of wort for boil. I did use 1.75 qt/pd for my mash in, but was still getting temperature drops from mash in at 153 drop to about 147 by the end. I have a fair about amount of deadspace above my mash because I have a big cooler. Could that be a big part of my efficiency problem?

How can I better insulate my cooler to stop this significant drop in temp?  Towels on bottom of tun and at the top?  Towel around the ball valve? How can I fill up some of that deadspace inside?  Foil inside my mash tun?

I am open to any and all ideas, particularly from those with experience with round mash coolers.

The temp drop could affect your fermentability, but it's very unlikely that it affected your efficiency.
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Offline nicosan1

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Re: Mash Efficiency Problem
« Reply #122 on: September 16, 2013, 11:23:02 AM »
Should I just bump up my strike water temperature to start at a higher fermentation temp bring it down a bit ?

I took a temperature in two spots right after stirring (152 F) then closed the lid, but by 75 minutes was down to 146. Could it be that I need to wait about 5-10 minutes after first stirring to get a true temperature reading of the mash after heat exchange?

Offline nicosan1

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Re: Mash Efficiency Problem
« Reply #123 on: September 16, 2013, 11:30:23 AM »
Denny, so major change in temp doesn't effect the enzyme activity in the mash? Just that you get more fermentable sugars at lower temps (146) and more unfermentable at higher temps (156)? 


Offline kramerog

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Re: Mash Efficiency Problem
« Reply #124 on: September 16, 2013, 11:36:28 AM »
I looked at your plan.  Step 3 involved opening the tun and adding Midnight Wheat.  If you mixed the Midnight Wheat in well, you probably lost the bulk of your 6 degrees at that time.  Because you had already mashed for nearly an hour, the consequences of a temp drop at that time would be inconsequential.
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Offline nicosan1

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Re: Mash Efficiency Problem
« Reply #125 on: September 16, 2013, 11:47:16 AM »
Thats true, I did add that, and opening and briefly stirring may have resulted in some of that. I was just wondering, if you stir at begging of mash in and you take temp, it will still drop more correct given that it takes time for strike water and grain to mix and create one solid temp. Should I strike slightly high with a reading of 154 if I want to hit 151? given it takes time for grain/water mix.

Online morticaixavier

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Re: Mash Efficiency Problem
« Reply #126 on: September 16, 2013, 12:06:24 PM »
Thats true, I did add that, and opening and briefly stirring may have resulted in some of that. I was just wondering, if you stir at begging of mash in and you take temp, it will still drop more correct given that it takes time for strike water and grain to mix and create one solid temp. Should I strike slightly high with a reading of 154 if I want to hit 151? given it takes time for grain/water mix.

If you have stirred everything in really well the temp should not drop much more than your measurement. Do you see steam escaping around the lid on cold brew days? if so cover the whole thing in some heavy blankets and see if that helps. Add the midnight wheat right before you sparge instead of in the middle of the mash and it will matter even less than KRAMEROG stated.
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Offline nicosan1

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Re: Mash Efficiency Problem
« Reply #127 on: September 16, 2013, 12:11:20 PM »
I did not see any steam. I have one these coolers as my mash tun: http://www.homedepot.com/p/Rubbermaid-10-Gallon-Water-Cooler-Orange-Cooler-FG1610HDORAN/202260809#.UjdXedK-q2E

The lid seems to be solid plastic, not necessarily insulate. But no steam escaped. When I would go to touch the lid, you could feel the plastic was hot. However, I am wondering if I should put towels over the lid and below the cooler and around the ball valve to limit any exchange of heat that could contribute to heat loss.

Offline kramerog

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Re: Mash Efficiency Problem
« Reply #128 on: September 16, 2013, 12:19:51 PM »

If you have stirred everything in really well the temp should not drop much more than your measurement.

+1.

I had a mash tun from the same Rubbermaid cooler.  I would loose only 1 deg F over an hour for 10-gal batches.  The lid should be fine.
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Offline nicosan1

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Re: Mash Efficiency Problem
« Reply #129 on: September 16, 2013, 12:42:20 PM »
kramerog, if I was brewing a 5 gallon batch from say 13.5 lbs of grains and about 5.9 gallons of strike water in that 10 gallon MLT, would I lose more than 1 degree in heat?  Just wondering because I read a lot on blogs that if you are doing 10 gallon batches you should lose little, but more dead space on top of mash you lose more temp.

Thanks again.

Offline denny

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Re: Mash Efficiency Problem
« Reply #130 on: September 16, 2013, 12:49:29 PM »
Denny, so major change in temp doesn't effect the enzyme activity in the mash? Just that you get more fermentable sugars at lower temps (146) and more unfermentable at higher temps (156)?

Correct.  You'll still get conversion at the lower temp.  I think it's likely you didn't stir enough.
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Offline kramerog

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Re: Mash Efficiency Problem
« Reply #131 on: September 16, 2013, 12:55:15 PM »
I'm not aware of any correlation between heat loss and headspace.  I suspect that your 5-gal batch looses about the same amount of heat as a 10-gal batch but since your batch is smaller you would get a bigger temp drop on the order of 1.5 deg F.  In any case my mash volumes were not dramatically bigger than yours because I used to mash at 1.25 qts/lb until I got a bigger cooler.

If you are really worried about temp loss and headspace, use still more water!
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Offline VinS

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Re: Mash Efficiency Problem
« Reply #132 on: September 16, 2013, 01:03:36 PM »
Nicosan 1, Did you increase temp of strike water for loss of heat because of temp of the grain? also do you pre heat cooler.
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Offline nicosan1

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Re: Mash Efficiency Problem
« Reply #133 on: September 16, 2013, 01:14:52 PM »
Denny - I tried to get my strike temp too be 170 in my kettle so that when I transferred it using a one gallon metal jug I would lose a few degrees to be about 166 so that I could get it to 151 after adding grain. I was at about 156 after stirring for half a minute, then I stirred some more and added some pieces of ice to lower to about 152, after stirring for another half a minute.

VinS, I did pre-heat my cooler with 1 gallon of boiling water that left in sealed, emptied just before adding strike water.

Kramerog, I used 1.75 qt/pd so I guess I could go to 2 qt/pd to limit, though I probably won't have to do much of a sparge on that I suppose.



Online morticaixavier

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Re: Mash Efficiency Problem
« Reply #134 on: September 16, 2013, 01:20:36 PM »
Denny - I tried to get my strike temp too be 170 in my kettle so that when I transferred it using a one gallon metal jug I would lose a few degrees to be about 166 so that I could get it to 151 after adding grain. I was at about 156 after stirring for half a minute, then I stirred some more and added some pieces of ice to lower to about 152, after stirring for another half a minute.

VinS, I did pre-heat my cooler with 1 gallon of boiling water that left in sealed, emptied just before adding strike water.

Kramerog, I used 1.75 qt/pd so I guess I could go to 2 qt/pd to limit, though I probably won't have to do much of a sparge on that I suppose.

I stir for about 5-10 minutes till I am getting consistent temp readings throughout the mash. Actually I stir till I am not seeing any more dough balls and that also tends to result in a consistent mash temp. If you are adding a couple degrees to your strike temp you don't really need to pre-heat with separate water, add the strike water and close up the tun for a couple minutes. Plastic will pre-heat very quickly.
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