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First AG brew, terrible efficiency

Mashing
#1

So I finally got to try out my new AG equipment and my efficiency was horrendous (63.5%). Hoping someone can see what might have caused it. I brewed the Dead Ringer all grain kit (11lbs Rahr 2-row and 1lb C40). The crush looked exactly like all the pictures I’ve seen of grain considered a good crush. The grain was crushed about 2 months ago but was kept in double plastic bags so I don’t believe any moisture got to it.

I used brunwater to determine pH and was calculated at 5.4 at room temp. I heated my strike water (5 gallons) to 175 and poured it into my 70qt cooler and closed it to preheat it. This brought it down to about 165, then I doughed in and my temp went down to around 158. My target was 152 so I poured about half a gallon of 120* tap water and hit my target almost dead on.

After 1 hour I vorlaufed and drained the mashtun. I got 4 gallons of run off so I added 3 gallons of strike water at 175*, stirred like crazy, vorlaufed and drained again. Then something weird happened. After completely draining the mashtun I only got 2 gallons of run off. I’m not too sure where the other gallon went but the mashtun was drained. I heated 4 gallons of sparge water so I added the final 1 gallon and repeated the sparge process to get my final 1 gallon to put me at 7 gallons.

This yielded a wort of 1.040 which according to

is 63.49% efficiency.

After the boil I was at 1.049 so I added about 0.75lbs of sugar to get me closer to my 1.064 target OG. I didn’t have any DME on hand so hoping It doesnt come out too dry.

So any thoughts on what could have caused such a low efficiency?

#2

Did you use three gallons and three quarts of strike water? (1.25 x lbs of grain = quarts of strike water). I might be reading this wrong, but it looks like you used too much strike water in your initial mash and then sparged with too little. That doesn’t explain the missing gallon though. On further investigation, mash thickness doesn’t seem to play too much into efficiency as long as there’s enough water - which you had, but running less than 5 gallons of sparge water through the grain after conversion might have done it.

#3

5 gallons (actually 5.5) is a little bit much strike water, but not so much that I think that’s your problem. It comes out to a water:grain ratio of 1.83 which is high, but not so high that I’d expect such poor efficiency.

I think you are right in that the clue here is that you used 9.5 gallons of water and only yielded 7 gallons of pre boil wort volume. Even factoring it grain absorbtion and dead space in the MLT, there’s a gallon missing somewhere and I think that’s the clue to the source of the problem.

#4

I think NB’s kits are for 75% efficiency/5 gallons final volume, your OG would be around 1.055 @ 63% for 5 gallons.

Looks to me you over shot your boil volume, it takes a big pot to boil off 2 gallons.

#5

Yeah I like to have 1/2 gal left in the boil kettle to leave hops and break behind. My kettle is about 1.2 gallons boil off per hour. I try to shoot for 5.25 in the fermentor. So I hit my target for boil volume but I guess I should have thrown another lb of base malt at it. Still would like to understand why my efficiency was so bad. Maybe just a fluke.

#6

63 is not that bad. I still bet you could go tighter on the crush and squeeze out a couple more points. Also it helped me to stir a lot after adding the sparge water, stir till you think is good then stir some more.

#7

The crush of the malt…

I think bringing up the OG with sugar is a good idea, it will help balance the beer out. I use sugar quite a bit, it’s a cheap fermentable. I like to keep it under 5-7% though.

#8

Is your thermometer accurate?

#9

Yes it’s from thermoworks. Not a thermopen but a thermocouple. Tested against others that I know to be accurate just a few days ago.

#10

If I’m reading your post correctly, you used 5 gallons of water in the mash tun for the conversion rest, which is a bit much by my reckoning. If you used 10 lbs. of grain ( just to throw a ballpark figure out there that’s probably not too far off the mark), that gives a water to grist ratio of 2:1, which is well above the usual range of 1 to 1.5 quarts of water per pound. I’m thinking that the mash was just a bit too thin to achieve good conversion efficiency. Then again, recipes from commercial breweries regularly quote water to grain ratios of more like 2.5 or 3 to 1, but that’s with commercial equipment, so I don’t now. Maybe I’m totally off the mark here. That’s just my initial thought.

#11

I did a little follow up reading on this as my initial post was that the mash was too thin. From what little I gleaned, mash thickness doesn’t have much to do with efficiency - though having too little water/to thick a mash could be a problem - that’s not the case here. There might be a problem on the sparging end in not having enough sparge water to rinse the converted sugars off the grain.

#12

As a batch sparger, here’s how I would deal with a 12 lb grain bill.
Mash in with 15-16 quarts of water.
At the end of the mash, add 4 quarts of boiling water to help with runoff and to also squeak the last bit of conversion out (I find this usually brings me into the 158-164F range, depending on my mash temp, which isn’t enough to kill the enzymes so it’s not a true “mash out”)
Run off, which should give about 3.5 gallons of wort. Measure your gravity and volume here. I use Kai Troster’s “batch sparge simulator.xls” at this point to determine mash effeciency, just to make sure I got the conversion I was looking for. Your first runnings here should be in the 1.060-1.075 (15-19 P) range.

Then add 3.5 gallons of 180F water as your sparge. Stir well as you add it-- this is key! I find if I wait to stir the batch sparge, the grains have really compacted from the first runoff. Wait a few minutes, vorlauf, and run off. I like to measure the gravity of this wort as well and it typically is around 1.024-1.032 (6-8 P).

This should yield 7 gallons of wort of around 1.042-1.046, which when you boil off and account for dead space would get you to 1.058-1.062. You absolutely need to factor in the fact that you are not in fact brewing 5 gallons, but rather 5.75.

#13

I still would like to know where my mystery 1+ gallon of water went from my sparge run-off. It’s like the grain absorbed more water during sparging. Anyone ever had that happen?

#14

If there was a wad of grain that didn’t get mixed well enough when you doughed in, this could explain both poor efficacy and some of your vanishing water. I brew another batch and see if you have the same problems. As you get into a rhythm, your efficiency problems may go away.

#15

That actually makes sense. Now I need to decide to assume 64% efficiency when building my next grain bill or something a little higher. Maybe shoot for 70% and if miss it either way it won’t be too bad?

#16

2:1 is fine and will actually increase efficiency over a lower ratio.

#17

[quote=“mattnaik”]So I finally got to try out my new AG equipment and my efficiency was horrendous (63.5%). Hoping someone can see what might have caused it. I brewed the Dead Ringer all grain kit (11lbs Rahr 2-row and 1lb C40). The crush looked exactly like all the pictures I’ve seen of grain considered a good crush. The grain was crushed about 2 months ago but was kept in double plastic bags so I don’t believe any moisture got to it.

I used brunwater to determine pH and was calculated at 5.4 at room temp. I heated my strike water (5 gallons) to 175 and poured it into my 70qt cooler and closed it to preheat it. This brought it down to about 165, then I doughed in and my temp went down to around 158. My target was 152 so I poured about half a gallon of 120* tap water and hit my target almost dead on.

After 1 hour I vorlaufed and drained the mashtun. I got 4 gallons of run off so I added 3 gallons of strike water at 175*, stirred like crazy, vorlaufed and drained again. Then something weird happened. After completely draining the mashtun I only got 2 gallons of run off. I’m not too sure where the other gallon went but the mashtun was drained. I heated 4 gallons of sparge water so I added the final 1 gallon and repeated the sparge process to get my final 1 gallon to put me at 7 gallons.

This yielded a wort of 1.040 which according to

is 63.49% efficiency.

After the boil I was at 1.049 so I added about 0.75lbs of sugar to get me closer to my 1.064 target OG. I didn’t have any DME on hand so hoping It doesnt come out too dry.

So any thoughts on what could have caused such a low efficiency?[/quote]

Crjush is always the #1 factor in efficiency. Did you crush it yourself?

Your volume problems are puzzling. Did you tip the cooler to be sure all the wort got drained?

#18

When I first started doing AG I had terrible efficiency, much worse than yours. I tried fixing every aspect of it, but crush, in an attempt to avoid buying a barley crusher. I finally broke down and bought one and my efficiency went through the roof.

#19

[quote=“Denny”]

Crjush is always the #1 factor in efficiency. Did you crush it yourself?

Your volume problems are puzzling. Did you tip the cooler to be sure all the wort got drained?[/quote]

No I did not crush it myself I got it from NB pre-crushed. I’ve been eyeballing the captain crush but $280 is a hefty price tag. Of course if i keep getting crappy efficiency, it may pay for itself eventually.

I did not tip the cooler and it wasn’t till i cleaned out the mashtun that i realized that there was quite a bit of deadspace under the bazooka screen. This still doesn’t explain the loss of volume from sparge because that same volume would have been there after my first runnings.

#20

+1 to both of Denny’s comments. I routinely mash somewhere between 1.75 - 2qt/lb without any issues. I can actually confirm I get better efficiency then when I mash thicker like 1.25 - 1.5qt/lb.

Also completely agreeing on the crush. I ordered a few AG kits from NB years ago and my efficiency was around 65-70%. I switched to crushing my grain at my LHBS and was getting 70-75% on average. I finally got a grain mill back in October and am now getting 75-85% efficiency. Nothing else changed in my process. I did experiment with other BIAB methods over that time (no sparge, full volume mashing, etc) but am back to good old normal mash, batch sparge and again, I’m routinely between 75-85% efficiency depending on the size of the grain bill.

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