Humiliatingly low efficiency

[cladinshadows]

I just finished my third AG batch today, and my brewhouse efficiency was ridiculously low. I calculated it at 55%.

Can somebody help me diagnose the problem?

I use a home depot 10 gal beverage cooler as my MLT with a steel braid over vinyl tubing, per flyguy's great how-to.

Grain bill consisted of 9 lbs. or pal 2-row, 9 lbs. of vienna and 1/2 lb. of cara-pils and a backup addition of 3 lbs of DME.

Mash was a two-step infusion, first at 133 degrees with 1.25 qt/lb of grain for 30 minutes, second at 151 degrees with a total ratio of 1.65 qt/lb of grain for 60 minutes. I did an iodine test to confirm conversion at that point. I drained all of the runnings and batch sparged with 6.5 gal of 170F (even though I should be using about 9 gallons, I doubt that can account for this big of a discrepancy). First runnings went into an IPA, second runnings went to a very mild pale ale. I preheated the tun as well.

Based on my experience with my apparent lack of skill, I figured I'd miss my intended gravity by a lot, so I added 1.5lbs. of DME to each.

In the end, I collected 5 gallons of 1.072 wort for the IPA, and 4 gallons of 1.033 wort for the PA. When I calculate that out as if it were a single batch, I get 9 gallons of 1.055 wort, from 18.5 lbs of grain and 3 lbs of DME. That comes to a 55% brewhouse efficiency.

I hit my temps, checked for conversion, everything seemed fine. I don't believe the crush is an issue, as I had my LHBS mill it twice. Does anybody have an idea of where I'm going wrong? I am getting frustrated as all three of my AG batches have had similarly low efficiency!

 

[mbird]

what do you mean, steel braided over vinyl tubing? I have a s.s.braided hose in my mash tub. No vinyl.
mark
Beer Diary...

 

[cladinshadows]

It's food-grade vinyl tubing with slots cut into it, inserted into the SS braid and attached to a barbed hose bib and ball valve. The point is to prevent the SS braid from collapsing in the mash and causing a stuck sparge. The wort flows easily, and it is unlikely that this assembly had an impact on my efficiency. I was able to collect all the wort I wanted through it...

 

[eriktlupus]

when batch sparging.

the first runnings will contain roughly 1/2-2/3 of your total sugars
the second will get out roughly half of the remaining
and a third will get out most of the rest

now by cutting your sparge water by a third your also going to leave probably 1/4 of your total sugars behind

when i plug your numbers into my extrction calculator i get

(18.5 x 36)+(3 x 44) /9= @88
55/88=62%

now going by that 1/4 of your total sugars would be 22 points

 

[mbird]

5 gal. at 72 is 360 + 4 gal. at 33 is 132 (132+360=492 divided by 9gal=1.055

18.5 lbs. x 37 = 684 divided by 9gal=1.076 x 73% efficiency = 1.055

this is of course before the addition of malt extract

mark
Beer Diary...

 

[mbird]

I just have the s.s.braid and it doesn't collapse. I have had as much as 24lbs of grain on it, then again I fly sparge so maybe that helps.
mark
Beer Diary...

 

[cladinshadows]

when batch sparging.

the first runnings will contain roughly 1/2-2/3 of your total sugars
the second will get out roughly half of the remaining
and a third will get out most of the rest

now by cutting your sparge water by a third your also going to leave probably 1/4 of your total sugars behind

when i plug your numbers into my extrction calculator i get

(18.5 x 36)+(3 x 44) /9= @88
55/88=62%

now going by that 1/4 of your total sugars would be 22 points

This neglects the fact that a good portion of this is malt extract. The 100% efficiency from the DME increases my brewhouse efficiency significantly (albeit still to just 62%!).

5 gal. at 72 is 360 + 4 gal. at 33 is 132 (132+360=492 divided by 9gal=1.055

18.5 lbs. x 37 = 684 divided by 9gal=1.076 x 73% efficiency = 1.055

this is of course before the addition of malt extract

mark
Beer Diary...

The DME makes a big difference:

18.5 lbs. x 37 = 684 / 9gal x 55% = 1.041 + 3 x 44 x 100% = 1.055

My concern is how low my extraction from the mash is.

I just have the s.s.braid and it doesn't collapse. I have had as much as 24lbs of grain on it, then again I fly sparge so maybe that helps.
mark
Beer Diary...

I'm not suggesting that a SS braid won't work on its own. I followed flyguy's how-to, some people reported issues with their braid collapsing, so I decided to incorporate that as part of the initial design, rather than getting a stuck sparge and being (even more) SOL on brewday!

Thanks for the replies, hopefully someone can still give me an idea of why my eff is so bad!

 

[ajf]

I think your sparge water was too cool. If you were mashing at 151, and drained your first runnings, your sparge temperature with 170 degree sparge water would be well below the optimum 168. I would suggest at least 185 for the sparge water temp.

When you added the sparge water, did you give it a good stir? This is necessary to dissolve the sugars.

-a.

 

[cladinshadows]

I think your sparge water was too cool. If you were mashing at 151, and drained your first runnings, your sparge temperature with 170 degree sparge water would be well below the optimum 168. I would suggest at least 185 for the sparge water temp.

When you added the sparge water, did you give it a good stir? This is necessary to dissolve the sugars.

-a.

I actually let the sparge sit for awhile and gave it several stirs in the meantime, because I was busy working out a gravity reading for the first runnings. I probably let it sit a good 10 minutes with 3 stirs during that time. The actual temp of the water in my MLT was 167 during the sparge.

 

[GreenwoodRover]

What were the efficiencies in yout first two batches? Was the equipment the same?

I agree with the sparge water temp brough up by ajf, but that shouldn't account for the sub 60%.

Another question, the way I read it it looks like you added the the DME to the mash tun, is that correct?

 

[cladinshadows]

The efficiencies were similary bad/worse. #1 was a stovetop all grain half-batch where I hit about 65%. #2 was the first time I used my MLT and I hit 49%. Today I hit 55%.

DME was a late addition, added to the boil at t-minus 15 minutes.

Another note: batch #2 I used campden tablets to dechlorinate the water. Today I used an in-line carbon filter for my water.

 

[The Pol]

I am a little confused about the need for a two step mash...

 

[Bernie Brewer]

I think your sparge water was too cool. If you were mashing at 151, and drained your first runnings, your sparge temperature with 170 degree sparge water would be well below the optimum 168. I would suggest at least 185 for the sparge water temp.

When you added the sparge water, did you give it a good stir? This is necessary to dissolve the sugars.

-a.

+1. When fly sparging (which you are NOT doing) a mash-out of 168-170 will boost efficiency. Since you are batch sparging, you don't need to do this, because adding sparge water will raise temps. BUT your sparge water needs to be higher than the 170 in your HLT since it will lose temp in the transfer. So your sparge water needs to be 180-185 in your HLT to hit the 168-170 in your mash tun. Make sense???

 

[ajf]

I actually let the sparge sit for awhile and gave it several stirs in the meantime, because I was busy working out a gravity reading for the first runnings. I probably let it sit a good 10 minutes with 3 stirs during that time. The actual temp of the water in my MLT was 167 during the sparge.

OK, that brings up some other points.

Have you calibrated your thermometers?

If you mashed at 151, and drained all the runnings, your grain would cool to substantially less than 151 by the time you added your sparge water. Even assuming it stayed at 151, you would need over 17 gallons of sparge water to raise the mash temperature to 167 assuming that you drained it all (no dead space) and assuming 1 pt / lb for grain absorption. You will have some dead space, but not enough to make that sort of difference, and the grains will have cooled considerably. There is a serious temperature discrepancy here.
The next thing is that you appear to have done a single batch sparge. This is very inefficient (especially with a large grain bill and relatively small amount of sparge water) as the wort trapped in the grains and the dead space will have a gravity equal to that of the collected wort. If you do two batches of approximately equal value, the first batch will have a much higher gravity than the second, meaning that you leave much less sugar behind.

-a.

 

[Yankeehillbrewer]

I actually let the sparge sit for awhile and gave it several stirs in the meantime, because I was busy working out a gravity reading for the first runnings. I probably let it sit a good 10 minutes with 3 stirs during that time. The actual temp of the water in my MLT was 167 during the sparge.

Like others have said sparge with 185* water, I saw a huge increase in my efficiency with that alone, that put me into 80's. I used to always sparge with water at 170*, never again.

When you add your sparge water, stir it really well once, and then let it sit for 10-15 mins to let the grain bed settle again. Vorlauf, Drain, repeat.

There's my 2 cents

 

[eriktlupus]

if youre only sparging once your still leaving sugars behind. split your total sparge volume into two equal sparges. this will increase your efficiency to respectable levels.


when i plug your numbers into my extrction calculator i get
grains + dme / 9 =total possible sugars
(18.5 x 36)+(3 x 44) /9= @88
55/88=62%

 

[cladinshadows]

I am a little confused about the need for a two step mash...

There's no need...I just enjoy the process and I figure it isn't going to hurt the result.

OK, that brings up some other points.

Have you calibrated your thermometers?

If you mashed at 151, and drained all the runnings, your grain would cool to substantially less than 151 by the time you added your sparge water. Even assuming it stayed at 151, you would need over 17 gallons of sparge water to raise the mash temperature to 167 assuming that you drained it all (no dead space) and assuming 1 pt / lb for grain absorption. You will have some dead space, but not enough to make that sort of difference, and the grains will have cooled considerably. There is a serious temperature discrepancy here.
The next thing is that you appear to have done a single batch sparge. This is very inefficient (especially with a large grain bill and relatively small amount of sparge water) as the wort trapped in the grains and the dead space will have a gravity equal to that of the collected wort. If you do two batches of approximately equal value, the first batch will have a much higher gravity than the second, meaning that you leave much less sugar behind.

-a.

I have three thermometers (a regular "analog" style, a digital instant meat thermometer, and another digital) that read within 1 degree of each other...hopefully they're ok! The sparge water temp is a great point.

Like others have said sparge with 185* water, I saw a huge increase in my efficiency with that alone, that put me into 80's. I used to always sparge with water at 170*, never again.

When you add your sparge water, stir it really well once, and then let it sit for 10-15 mins to let the grain bed settle again. Vorlauf, Drain, repeat.

There's my 2 cents

Thanks a lot for all of your responses. Next time I'll be using 185F sparge water and more of it. For anybody who batch sparges, how many times should I do it? The single batch sparge was based on the fact that I only have so much space to boil what I've collected...Would I be able to collect less wort but achieve greater efficiency if I decide to start fly sparging rather than batch?

I think I was getting ahead of myself trying to brew up 6 gallons of 1.080 wort by batch sparging with only an 8 gallon and a 5 gallon pot to boil down with. At any rate, thanks for the helpful responses!

 

[HughBrooks]

What type of themometer do you use? I had a similar problemwith my partialmash wit. target OG was and I ended up with 1.038-39. I was using a digital thermometer and I think tha it was reading anywhere from 10 to 20 high. so my mash temp was actually 130 instead of 150. and so on. Its just a thought hope you work it out

 

[HughBrooks]

Oops didnt see the one about the thermos till a second ago. Nevermind

 

[bob1852]

My views on efficiencey are now this after struggling with it myself:

1) accurate temperature measurement
2) accurate volume measurement
3) accurate gravity measurement

your technique looks good - just make sure your measurements are accurate.

and get your sparge water way hotter than you think you'll need - after listening to Bobby_M for awhile - I'm now sparging at 188-190, have seen a 10+ % jump in my efficiency and the grain bed doesn't get about 170...

 

[nchomebrew]

how does the beer taste?