Author Topic: Mash Efficiency Problem  (Read 11669 times)

Offline malzig

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Re: Mash Efficiency Problem
« Reply #45 on: August 04, 2013, 10:50:27 AM »
As for the dead space in my tun is a 10 gallon rubbermade with a mesh screen tube as the filter, 2/3 a gallon is what you would calculate my dead space to be?

A lower mash temp say of high 140s will slow down my conversion correct?
I estimated your dead space from the volume you added to the tun, minus 0.12 gal/# absorption rate, and your collected volume.  There seems to be about 2/3 gallons unaccounted for.

It's common for brewers to mash longer when they mash in the 140s.  I've never measured the effect, but below 150 F+ you are pushing the lower limit of efficient starch gelatinization.
I'd recommend a stir right before running off the first runnings, too.  When I have forgotten to do this I got reduced efficiency.
It's fascinating to hear about different techniques that people use.  For me, stirring before run off makes no difference.
I can only draw a correlation between lower than expected gravity on a few batches and realizing that I hadn't stirred.  It wasn't a solid data set, and the effect was minor, but it seemed to be reproducible and it threw me off my usually very predictable efficiency.  It's been a while, though, and it isn't really a variable in my current system, since I almost always do an alpha rest.   I saw a larger effect by forgetting to stir in the sparge water.  Not that I'm forgetful or anything...

Offline ynotbrusum

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Re: Mash Efficiency Problem
« Reply #46 on: August 05, 2013, 03:03:37 PM »
Does anyone out there add water after the mash period is ended, just to attempt to equalize the batch sparging volumes to be run off in the two batch sparges?  If so, that would impact the calculation, using Denny's system - maybe just have a lot of extra sparge water just in case and brew tea with it?
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Offline mtnrockhopper

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Re: Mash Efficiency Problem
« Reply #47 on: August 05, 2013, 03:10:22 PM »
Does anyone out there add water after the mash period is ended, just to attempt to equalize the batch sparging volumes to be run off in the two batch sparges?  If so, that would impact the calculation, using Denny's system - maybe just have a lot of extra sparge water just in case and brew tea with it?

Yes, that is the recommended way. Somebody (maybe Denny) did tests and found it provides the best efficiency. Just use the same total sparge water for both additions. I heat the full amount at once since they are used within a short time frame.
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Online morticaixavier

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Re: Mash Efficiency Problem
« Reply #48 on: August 05, 2013, 03:13:04 PM »
Does anyone out there add water after the mash period is ended, just to attempt to equalize the batch sparging volumes to be run off in the two batch sparges?  If so, that would impact the calculation, using Denny's system - maybe just have a lot of extra sparge water just in case and brew tea with it?

not just for that reason but I will often add some hot water before runoff because I do no-sparge and I don't want the actual mash ratio that high.
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Re: Mash Efficiency Problem
« Reply #49 on: August 05, 2013, 03:13:47 PM »
I've been doing it lately.  I think I get the most consistent efficiency that way.  I usually mash 1.5 -1.75 qts/lb, so whatever volume of water I need to run off exactly 3.5 gallons from the mash is what I add at the end of the mash. It's easy then to use exactly the same volume of sparge water each time.
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Offline denny

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Re: Mash Efficiency Problem
« Reply #50 on: August 05, 2013, 03:24:21 PM »
Does anyone out there add water after the mash period is ended, just to attempt to equalize the batch sparging volumes to be run off in the two batch sparges?  If so, that would impact the calculation, using Denny's system - maybe just have a lot of extra sparge water just in case and brew tea with it?

Yes, that is the recommended way. Somebody (maybe Denny) did tests and found it provides the best efficiency. Just use the same total sparge water for both additions. I heat the full amount at once since they are used within a short time frame.

Actually, I got the info from Ken Schwartz, but I believe he derived it mathematically rather than empirically.  But in truth, it doesn't matter all that much.  Having runoffs within a gal. or so of each other has so little impact on efficiency that you likely would never notice.  These days, I usually mash with enough water that I don't have to do the addition before I run off.  Save some work and it's pragmatic!
« Last Edit: August 09, 2013, 09:08:04 AM by denny »
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Offline narvin

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Re: Mash Efficiency Problem
« Reply #51 on: August 05, 2013, 06:47:24 PM »
Mash thinner!  If you're considering adding extra water to your mash tun before the sparge to equalize volumes, just use it all in the mash.  At the homebrew scale, 1.5 - 2.0 qts/lb isn't too much.   I've found that with just an average crush and 1.25 qts/lb, I don't get 100% mash conversion in 60 minutes.  A lower mash temperature (it sounds like you stabilized at 148) exacerbates the problems with a thick mash.  Stirring or extra time would help, but a thinner mash just works better.  As it was mentioned above, an iodine test won't tell you if all of the starches have been extracted; you need to measure the gravity.
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Offline ynotbrusum

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Re: Mash Efficiency Problem
« Reply #52 on: August 05, 2013, 07:10:22 PM »
Mash thinner!  If you're considering adding extra water to your mash tun before the sparge to equalize volumes, just use it all in the mash.  At the homebrew scale, 1.5 - 2.0 qts/lb isn't too much.   I've found that with just an average crush and 1.25 qts/lb, I don't get 100% mash conversion in 60 minutes.  A lower mash temperature (it sounds like you stabilized at 148) exacerbates the problems with a thick mash.  Stirring or extra time would help, but a thinner mash just works better.  As it was mentioned above, an iodine test won't tell you if all of the starches have been extracted; you need to measure the gravity.

Yes, that's what I do typically (1.5-1.75 qts/lb) - plus it makes Denny's approach all the easier to implement - the pragmatic way!  Thanks for the input and I apologize to the OP for the threadjack.
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Offline klickitat jim

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Re: Mash Efficiency Problem
« Reply #53 on: August 08, 2013, 12:42:01 PM »
I will try it once, just for you

Lemme know if it makes any difference.  I may owe ya an apology and a beer!

Just finished a 90 min mash, 5 gallons with 12lbs, no stir after doh in. 20° or 1.080 so once again Denny is the Master!
I also didn't lose much temp, about 2° in 90 min with my stainless MT and yoga mat insulator
« Last Edit: August 08, 2013, 12:55:43 PM by klickitat jim »

Offline nicosan1

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Re: Mash Efficiency Problem
« Reply #54 on: August 08, 2013, 01:13:24 PM »
great so no little loss on heat and hitting target OG, sounds good. Are folks typically covering their mash tun coolers to insulate heat? Does everyone typically pre-heat mash tun cooler with boiling water prior to adding strike water and mashing in?

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Re: Mash Efficiency Problem
« Reply #55 on: August 08, 2013, 01:26:09 PM »
great so no little loss on heat and hitting target OG, sounds good. Are folks typically covering their mash tun coolers to insulate heat? Does everyone typically pre-heat mash tun cooler with boiling water prior to adding strike water and mashing in?

I cover my mash tun if it's colder and I'm outside.  I use a thick wool blanket to help keep it from falling too  much.  Otherwise I just let it be and only lose a degree or two over a 60 minute mash.

I do preheat my mash tun with boiling water, but then my recipe is configured that way.  If I don't preheat, I will undershoot my mash temp unless I heat my water a bit more and then it's a guessing game.  Preheating makes it easier for me to hit my temp within a few tenths of a degree.
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Offline dmtaylor

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Re: Mash Efficiency Problem
« Reply #56 on: August 08, 2013, 01:43:31 PM »
I don't preheat my mash tun with boiling water.  I just heat the water an extra 12 F than my calculator says.  Works really well.  I always boil an extra couple of quarts of water on the stove at the same time just in case the mash gets too hot.  Only very rarely have I needed to use it.  And rarely I need to stir or add cold water because it got too hot.  Typically no adjustments are required because it's within a degree or two of desired.  With experience you'll learn how many extra degrees are needed to heat your mash tun so that you don't need to precondition.
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Offline kramerog

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Re: Mash Efficiency Problem
« Reply #57 on: August 08, 2013, 02:27:23 PM »
I don't preheat.  I add 6-8 degrees (8 in winter, 6 in summer) to the calculated mash temp to compensate for evaporation while mixing the water and malt.  I cover the tun because evaporation is the biggest source of heat loss.
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Offline scottNU

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Re: Mash Efficiency Problem
« Reply #58 on: August 08, 2013, 02:51:41 PM »
I don't preheat my mash tun with boiling water. 

Is there any downside to preheating the mash tun? Equipment issue perhaps?

Offline kramerog

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Re: Mash Efficiency Problem
« Reply #59 on: August 08, 2013, 03:08:01 PM »
I don't preheat my mash tun with boiling water. 

Is there any downside to preheating the mash tun? Equipment issue perhaps?

Preheating is an unnecessary step.  I believe most of my heat loss is due to evaporation and not to my cooler/mash tun anyway.

You don't have to preheat with boiling water; you could preheat with water at 150 F if you are worried about damaging your mash tun.. 
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