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Horrible Efficiency


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#41 codemonkey

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Posted 14 April 2014 - 07:30 PM

Is the gravity of the liquid in the MT higher towards the bottom? My first runnings were only 1.079, so would the leftover wort in the deadspace be significantly higher? Still not sure what my deadspace is, but my initial estimate seems a bit high. 20 lbs of grain absorbs a lot of liquid.



#42 positiveContact

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Posted 15 April 2014 - 03:21 AM

Those numbers look good, Guv.  Thanks for the data.  Similar to mine.  Looks like your efficiency is pretty constant up to a gravity of around 1.065, same as mine.  1.065 seems to be the natural cutoff for the definition of a big beer, beyond which efficiency will suffer a little unless special measures are taken to prevent losses.

 

I, too, tilt my mash tun.  Part of maximizing efficiency, for those who care, is to collect every last drop possible.  To those who might be losing a gallon, you're losing a butt-ton of fermentable sugars and efficiency.

 

another variable is almost all of those batches were 10 gallons and very often my runnings are not equal simply b/c i don't feel like dumping in a large sparge amount.  i could probably gain a little bit there as well.  but my main point is that even when not doing a lot of the little additional things that people often suggest i can still get pretty good efficiency.



#43 pods8

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Posted 15 April 2014 - 05:46 AM

20 lbs of grain absorbs a lot of liquid.

.6-.7qt per lb in my experience.

#44 positiveContact

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Posted 15 April 2014 - 06:28 AM

.6-.7qt per lb in my experience.

 

is that really the number?  i've been using 0.4 qt (0.1gal/lb).



#45 HVB

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Posted 15 April 2014 - 06:50 AM

is that really the number?  i've been using 0.4 qt (0.1gal/lb).

For my system I am at 0.136gal/# with the manifold I have been using.  I was at 0.126gal/# when I had a braid on.



#46 pods8

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Posted 15 April 2014 - 07:03 AM

is that really the number?  i've been using 0.4 qt (0.1gal/lb).

 

Mine 48qt igloo with PVC manifold and a large load of grain (20-30lb) seems to be ~.6 conservatively, when using less grain the amount lost to the system verse grain adsorption would be higher so I padded the upper end number because also an extra quart of water is hardly noticeable.



#47 positiveContact

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Posted 15 April 2014 - 07:04 AM

For my system I am at 0.136gal/# with the manifold I have been using.  I was at 0.126gal/# when I had a braid on.

 

strange.  it's rare that i don't hit my preboil volume.  sometimes i even get an extra half gallon.

 

i figured grain absorption was pretty much the same for everyone.


Edited by TheGuv, 15 April 2014 - 07:04 AM.


#48 matt6150

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Posted 15 April 2014 - 07:04 AM

I have been at 0.13 with a manifold in a cooler.

#49 HVB

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Posted 15 April 2014 - 07:07 AM

strange.  it's rare that i don't hit my preboil volume.  sometimes i even get an extra half gallon.

 

i figured grain absorption was pretty much the same for everyone.

I guess I should have clarified.  I have my number set up for grain absorption and dead space. So it may be skewed a bit.



#50 pods8

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Posted 15 April 2014 - 07:13 AM

I guess I should have clarified.  I have my number set up for grain absorption and dead space. So it may be skewed a bit.

 

Same, sorry should have clarified earlier.  I don't recall what my fixed deadspace is and then apply the grain on top.  I tend to find just using a .6qt/lb assumption works for me.



#51 3rd party JKor

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Posted 15 April 2014 - 07:49 AM

I always had low efficiency in the past and now that I'm getting back into brewing I'd like to address this. Today's mash was 10 lbs of Rahr 2-row and 10 lbs of Rahr wheat. 5 gallons pre-boil clocked in at 1.073, which according to the web calculators is something like 48% efficiency. Yikes!

 

I batch sparge with one of those blue igloo ice cubes with SS braid. My first infusion was 6.25 gallons - 1.25 qt/lb. I mashed for 90 mins and the iodine test was clear. First wort was 3 gallons at 1.079. The second batch was 2 gallons for a total of 5 gallons in the kettle.

 

My pH seems a bit high. My strike water was 6.49. After 15 mins, the mash pH was 5.90 @ 32.8 dC, which I think means I was still about 0.4 points high at mash temp.

 

I don't expect to be able to get 80% with beers this big, but surely I should be able to get closer to 60%, no? What about a pro brewery, how do they get good efficiency with big beers?

 

Is the gravity of the liquid in the MT higher towards the bottom? My first runnings were only 1.079, so would the leftover wort in the deadspace be significantly higher? Still not sure what my deadspace is, but my initial estimate seems a bit high. 20 lbs of grain absorbs a lot of liquid.

 

You definitely have a conversion efficiency issue.  1.079 first wort for a 1.25qt/lb is about 82% conversion efficiency.  You should be seeing >95%.  Likely culprits:  crush, pH, poorly hydrated mash, temperature variations. 

 

I've used crushes from multiple LHBS's and varied my own crush levels to try to effect efficiency and the effect has been minimal at best.  I've never had any kind of issue with efficiency related to the crush.  I think people go to the crush as the problem solver for efficiency way too quickly.  In most cases people tighten up their crush and it improves efficiency and they think 'problem solved!' but the original problem is still there.

 

OTOH, i have had very noticeable efficiency loss due to pH.  5.9 is quite high.  How were you measuring that number?  If you were using ColorpHast strips, did you take into account Kai's offset?  if not, that would be a true reading of 6.2-6.3.  That would certainly kill your conversion efficiency.

 

You were brewing a very high gravity beer, it looks like your target OG was over 1.100.  With beers in that range, even with my system which regularly exhibits 85% efficiency on beers <1.060, I would only expect 70% efficiency.  On a less dialed in system, 60-65% is more likely.  So even in the case of good conversion efficiency (95%), lauter efficiencies for that size brew are ~65% (Conv. Eff * Lauter Eff = Brewhouse Eff.; 95%*65%=62%).  In your case you appear to have had ~82% conversion efficiency.  If you were to assume a 65% lauter efficiency it would give you a brewhouse efficiency of 53%.  So it also looks like your lauter efficiency is sub-par.

 

To me it looks like you are fighting multiple issues.  I'm generally not one to jump on crush as the main efficiency culprit, I think it's an overused solution since it's easier than attacking the other problems.  I think pH and lautering should be the two areas you look at.  I'd hold the crush as a constant and attack that last if the pH and lautering methods don't make significant improvements.



#52 codemonkey

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Posted 15 April 2014 - 07:57 AM

I used the brewersfriend recipe calculator and set the efficiency at 60%. I was targeting 1.085ish, which I think is a bit too high now, but hindsight and all. 

 

I have a Milwaukee MW102. I pulled a sample 15 mins after doughing in and cooled it to 32.8 dC and took the reading then. The pH of the first drain was 5.64 at 22.9 dC, which should translate pretty close to 5.2 at mash temp.

 

What do I do to address lauter issues? 


Edited by codemonkey, 15 April 2014 - 07:57 AM.


#53 3rd party JKor

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Posted 15 April 2014 - 08:01 AM

I missed the part about 1 gallon of dead space.  That's a killer if you're leaving 1 gallon of first wort behind.  Did you end up checking it?



#54 positiveContact

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Posted 15 April 2014 - 08:06 AM

I guess I should have clarified.  I have my number set up for grain absorption and dead space. So it may be skewed a bit.

 

that's a bit of an issue since your mash tun dead space won't scale with the amount of grain and should just be a constant.  in the end though it's not a huge deal if you are okay with slightly more/less wort going into the fermentor.  it's always going to make delicious beer :)



#55 codemonkey

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Posted 15 April 2014 - 08:19 AM

I missed the part about 1 gallon of dead space.  That's a killer if you're leaving 1 gallon of first wort behind.  Did you end up checking it?

No, not yet. I'm brewing again this weekend, though, so I'll get around to it... :D



#56 denny

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Posted 15 April 2014 - 08:20 AM

I was more concerned about aeration from mash to kettle. Tipping the mash tun to get the last bit out is going to cause air bubbles/gaps in the transfer line. The last time I brewed the jury was still out on whether or not this was a concern.

 

Don't worry about that at all.



#57 denny

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Posted 15 April 2014 - 08:22 AM

Codemonkey, I get my highest efficiency when I step mash or decoct. I also infusion mash in a blue ice cube. If I step mash, I get 85-90% efficiency. If I don't step mash I like to stir every 15-20 mins and get 70-75%. On a recent brew I did a single infusion and never touched it--no stirring. Got 60%-- worst I've gotten in years.Someone recently brewed one of my recipes with a 144/158F multi rest infusion. He reported his highest efficiency yet, 82%.I dont know if its extra time at mash temps, attacking beta and alpha amylase separately, extra stirring, raising temp at the end of the mash allowing for more sugar soluability or all of the above, but multi rest infusions really work to boost my efficiency.

 

FWIW, I average 83% with a single infusion, single batch sparge.  If a multi step mash made better beer, I'd consider it.  But I haven't found that.  My effieincy is good enough that I have no incentive to do a more complicated process just for the sake of efficiency.



#58 Steve Urquell

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Posted 15 April 2014 - 08:35 AM

FWIW, I average 83% with a single infusion, single batch sparge.  If a multi step mash made better beer, I'd consider it.  But I haven't found that.  My effieincy is good enough that I have no incentive to do a more complicated process just for the sake of efficiency.

I wish I could say the same. I've tried just leaving my mash alone over the mash period and it always comes up 10-15% low on efficiency. 60% is not acceptable to me when the only cost to raise it to 70-75% is stirring.



#59 denny

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Posted 15 April 2014 - 09:48 AM

I wish I could say the same. I've tried just leaving my mash alone over the mash period and it always comes up 10-15% low on efficiency. 60% is not acceptable to me when the only cost to raise it to 70-75% is stirring.

 

Wow, that's bizarre.  I wonder why it works like that for you?  For me, stirring does nothing but make me lose heat when I open the cooler to stir.  I've tried constant mash recirculation, too, and found no difference.



#60 positiveContact

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Posted 15 April 2014 - 10:10 AM

I wish I could say the same. I've tried just leaving my mash alone over the mash period and it always comes up 10-15% low on efficiency. 60% is not acceptable to me when the only cost to raise it to 70-75% is stirring.

 

do you think that perhaps you aren't mixing enough in the beginning?  are you checking to make sure there are no dough balls or anthing?  are you finding any part way through when you do the additional stirring?




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