25% efficiency....is that even possible?

So I've been wanting to make an oatmeal stout for quite sometime now. Problem is I've always done steeping grains/extract. I've never tried a PM batch. I honestly didn't think I even had the equipment for it, but then I realized I had a cooler, and a colonder that I use for straining sphagetti, and that was pretty much all I needed for a cheap, quick PM. Anyway, I threw together the following recipe:

5.5 lbs LME
6 oz roasted barley
8 oz chocolate malt
1 lb crystal 80
8 oz crystal 10
1 lb flaked oats
2 lbs 2 row
1 oz EKG
Nottingham

I put all the grains into my cooler, added 7 qts of 175 degree water, then stirred for a minute or two, and this brought my mash temp to 156 degrees. Pretty much what I was aiming for. So far so good. I put the lid on the cooler, put some blankets over it, and let it sit for just over an hour. While this hour was going by I realized my first mistake. I should have been sparging with at least 3 gallons of water, but with my brew pot the size that it is I would only be able to use 2 gallons of water. No biggy I thought to myself, I would just lose some efficiency. I knew my system wasn't that great anyway, and this was my frist PM, so I was only estimating 55% efficiency anyway. So after just over an hour goes by I take the lid off the cooler, and take the temp. 149 degrees. 7 degrees of loss isn't great, but I can deal with it. I put the collander over the brew pot, dump the grains in, and proceed to sparge with 2 gallons of water at 170 degrees.

So all the PM runnings are now in the brew pot (I haven't added any of the LME yet). It's about 3.5 gallons of wort. So I take a small sample, cool it down to around 60 degrees and take a hydrometer reading. 1.013!!! I put these numbers into promash and it looks like I only got around 25% efficiency. So, given the steps that I took above any ideas why that number is so low? The grain was crushed by the folks over at Realbeer.com. It smells great boiling, and I'm sure it will come out to be a fine beer anyway, but I'm still curious as to what could have gone wrong. I would think that just following the basic, correct steps I should be able to get 50% without even trying.

I dont have much experience with PM but I think you have to much specialty grains and not enough base malt, so inadequate enzyme power to convert all the starches.

The problem is that you needed some base malt in with the other grains....Those grains had very little Diastatic power on their own, so they didn't really convert from starch to sugar. What you ended up doing was just steeping the grains in a different place.

Hence the fact that you got such a low efficiency...on their own, those grins don't really give you many points of fermentables, they mostly just give you color and flavor.

In a true partial mash you are replacing an amount of extract with a conversion of base malt.

Take a look at this recipe of my brown ale, It is an extract with grains recipe, that was also formulated for various sized partial mashes as well as all grain; see how the extract amount and the 2-row amount changed depending on the size of the partial mash, all the way to the AG, yet the other grains, the ones like you used, stayed the same....

Note, this can be done either as a Partial Mash or an extract with special grains, as the vistory can be either mashed or steeped.

For partial mashes, I use an unmodified cooler with a wire folding steamer in the bottom and a large grainbag affixed with a rubber band. The steamer lifts the grainbag above the level of the spigot and helps prevent stuck sparges.

Basic Info (What the recipe should be, not what I got when I made it the first time (Numbers according to beercalculus.)

O.G. 1.072 (1.064 to 1.075)
F.G. 1.019 (1.017 to 1.021)
25° SRM (Brown to Dark Brown)
35.2 IBU
7.1% A.B.V.


Extract w/grains.
6# Light DME
1lb Victory
1lb Special Roast
1lb Crystal 60L
.25 Chocolate
1oz Cascade 6.3% AAU (@60)
.25oz Galena 13.4% AAU (@60) (Can use warrior, nugget or any high AA substitute depending on availability)
.5oz Fuggles 4% AAU (@20)
.5oz Fuggles 4%AAU (@5)

1 tsp Irish Moss at 15

Partial Mash in a 2 gallon cooler (4.25lbs. grains)
5lbs, 6oz Light DME
1lb 2-row
1lb Victory
1lb Special Roast
1lb Crystal 60L
.25 Chocolate
1oz Cascade 6.3% AAU (@60)
.25oz Galena 13.4% AAU (@60) (Can use warrior, nugget or any high AA substitute depending on availability)
.5oz Fuggles 4% AAU (@20)
.5oz Fuggles 4%AAU (@5)

1 tsp Irish Moss at 15

Partial Mash in a 3 gallon cooler (6lbs. grains)
4.25lbs Light DME
2.75lbs 2-row
1lb Victory
1lb Special Roast
1lb Crystal 60L
.25 Chocolate
1oz Cascade 6.3% AAU (@60)
.25oz Galena 13.4% AAU (@60) (Can use warrior, nugget or any high AA substitute depending on availability)
.5oz Fuggles 4% AAU (@20)
.5oz Fuggles 4%AAU (@5)

1 tsp Irish Moss at 15

Partial Mash in a 5 gallon cooler
3lbs Light DME
4lbs 2-row
1lb Victory
1lb Special Roast
1lb Crystal 60L
.25 Chocolate
1oz Cascade 6.3% AAU (@60)
.25oz Galena 13.4% AAU (@60) (Can use warrior, nugget or any high AA substitute depending on availability)
.5oz Fuggles 4% AAU (@20)
.5oz Fuggles 4%AAU (@5)

1 tsp Irish Moss at 15


Mash for 90 minutes @ 155 degrees (Heated the water to 170 and added to 69 degree grain) with 1.25 quarts of water/pound of grain. Batch sparge with 2 gallons. Add DME as you normally would.

All Grain Version
9lbs, 6oz 2-Row
1lb Victory
1lb Special Roast
1lb Crystal 60L
.25 Chocolate
1oz Cascade 6.3% AAU (@60)
.25oz Galena 13.4% AAU (@60) (Can use warrior, nugget or any high AA substitute depending on availability)
.5oz Fuggles 4% AAU (@20)
.5oz Fuggles 4%AAU (@5)

1 tsp Irish Moss at 15

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OOPs I didn't notice the 2-row....(customarily in a recipe base malts are listed first, that's why I didn't notice it.) I'm leaving work soon...if someone doesn't solve this before tonight, I'll run the numbers myself to see what happened....

He's got 2 lbs of 2-row in there, and the only grains or adjuncts that need conversion are the oatmeal (one pound). I would have to disagree and say he had plenty of diastatic power to do the conversion.

Personally, I think you measured/calculated something wrong. Just steeping the specialty grains alone should have dissolved enough sugars to get you to 25%.

Something isn't adding up here.

Revvy said:

The problem is that you needed some base malt in with the other grains....Those grains had very little Diastatic power on their own, so they didn't really convert from starch to sugar. What you ended up doing was just steeping the grains in a different place.

Hence the fact that you got such a low efficiency...on their own, those grins don't really give you many points of fermentables, they mostly just give you color and flavor.

In a true partial mash you are replacing an amount of extract with a conversion of base malt.

Take a look at this recipe of my brown ale, It is an extract with grains recipe, that was also formulated for various sized partial mashes as well as all grain; see how the extract amount and the 2-row amount changed depending on the size of the partial mash, all the way to the AG, yet the other grains, the ones like you used, stayed the same....

Click to expand...

I did use 2 lbs of 2 row Revvy. Are you saying the problem (as k1v1116 just stated) that I didn't use enough enough base grains?

FlyGuy said:

Something isn't adding up here.

Click to expand...

Pretty much what I'm thinking too. Maybe I did miscalculate something, but I have no clue where that miscalculation may have come from.

Ooompa Loompa said:

I did use 2 lbs of 2 row Revvy. Are you saying the problem (as k1v1116 just stated) that I didn't use enough enough base grains?

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I just edited my post.....I didn't see the 2-row originally....(customarily base malts are listed first in the grainbill.) I thought you just mashed your steeping grains...

I'm leaving work soon, if noone solves this I will run the numbers tonight.

Sorry....I thought I had it...

FlyGuy said:

He's got 2 lbs of 2-row in there, and the only grains or adjuncts that need conversion are the oatmeal (one pound). I would have to disagree and say he had plenty of diastatic power to do the conversion.

Personally, I think you measured/calculated something wrong. Just steeping the specialty grains alone should have dissolved enough sugars to get you to 25%.

Something isn't adding up here.

Click to expand...

Yeah, since he had it in the bottom of the grainbill I missed it....I think it's a math or measurement problem as well...

You should have been around 30 points for that 3.5 gallons if my brain is functioning properly now.

No it's still not functioning 44? I did everyone a favor and deleted my spaced out posts.

I just entered the grain bill into promash, if your hydro reading and wort volumes are accurate then it is around 25-26% efficiency.
After you added the LME and topped up to 5 gallons did you take another hydro reading? was it around 1.048 because thats what promash says it should be if you only got 25% on the partial mash.

Just took a reading and it came in at 1.051. Very odd.

Did you actually measure the final volume or just guesstimate it? From what I read, you mashed with 7 qts and sparged with 8 qts and say that you have about 14 quarts left over.

The only other thing I can think of is if the grains weren't crushed properly.

k1v1116 said:

I just entered the grain bill into promash, if your hydro reading and wort volumes are accurate then it is around 25-26% efficiency.
After you added the LME and topped up to 5 gallons did you take another hydro reading? was it around 1.048 because thats what promash says it should be if you only got 25% on the partial mash.

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This sounds right. You didn't have all of the sugars in the pot yet. Kind of like first runnings. Seems like you tried to calculate efficiency with the whole recipe not with just the first runnings.

I just guesstimated the final volume, however even if I only had 3 gallons (12 qts) left that would still only put me at around 30% instead of 25%. I think at this point it could be determined to be anything. Probably the best thing for me to do is make another PM batch (oh no!!! I have to make more beer.....oh man the sacrifices we must make sometimes) of something and see what kind of results I get from that. If it comes out at 25 to 30% again then I'm definately doing something wrong, if it comes in at 50% or above, then this was a fluke batch possibly caused by any number of things (grain crush, incorrect readings, incorrect measurements, very incorrect temps, old grain, etc).

When I do a PM, I always add up ALL of the specialty grains and use the same amount of 2-row. You have a lot of specialty grain there and although only the oats have to be mashed, all of the other grain will divert enzymes from the 2-row. That reduces the concentration and lowers the conversion rate. More mash water and a longer mash would have helped.

Also, my experiences with batch sparging, doing a single sparge really cuts into the efficiency.

Given your limit on boil volume, I would have mashed the oats, C10L and 2-row and steeped the rest in the sparge water while waiting for the mash to finish.

I would suspect that you have a number of things going on here.
Assuming the grain absorption figures that I get, you should only collect about 3g wort which will bump you efficiency to almost 30%. That's assuming that the strike and sparge water measurements were accurate. If they were short as well, your efficiency could be greater.

David made an interesting contribution about the enzyme concentration which makes a lot of sense to me.

I think the main problem however is your sparge. You dumped the grains into the colander, and rinsed them with the sparge water. This is effectively a fly sparge (you add water to the top, and it comes out of the bottom), but without giving the water a chance to dissolve the sugars. This will result in lousy efficiency.

With a batch sparge, you add the sparge water and stir to dissolve the sugars, and when the sugars are dissolved, you can drain. In your case, as you add the sparge water, it drops out of the bottom of the colander giving you no chance to dissolve the sugars.
If you get a grain bag, you could improve matters greatly. A 5g paint strainer bag from the hardware store should work well. Put the grains in the bag.

At the end of the mash, dump the grain bag into the colander on top of your kettle, and let it drain. You should also dump any liquid left in the mash tun (cooler) on top of the grain bag and let it drain into the kettle.
When it's completely drained, put the grain bag back into the cooler, and add 1/2 your sparge water at 180F, stir the crap out of it (nobody wants crap in their beer), put the grain bag in the colander, dump any liquids left in the cooler on top of the grain bag, and let it drain into the kettle.

Repeat this procedure for the second 1/2 of the sparge water, and your efficiency will improve dramatically.

-a.

Yup, AJF nailed it. Pouring through a colander is a horrible sparging technique.

Gotcha. Makes sense to me now. Thinking back on it now I should have know that, but for whatever reason it just didn't click in my head. Oh well, like I said it was my first PM, and it will still come out just fine, so no worries now. Live and learn as they say.

I would also try lowering the temp for the dough in. You poured in at a mashout temp.. adding 175 degree water in the beginning probably reduced the diastatic power by killing enzymes before they got started.

You can get decent efficiency in partial mashes with an umodified cooler, a grain bag and a folding steamer...I do it all the time with my little 2-gallon cooler, when I don't have a large grainbill and feel like wrestling with my larger cooler...

This is what I mean my a folding steamer, They can be found at any grocery store.



(You need to unscrew or break off the post in the center.)

Put the steamer in the bottom of the cooler, put in a grainbag and rubberband the bag to the top of the cooler.



The steamer simply lifts the grainbag above the spigot of the cooler, which creates a bit of a false bottom and also keeps the sparge from getting stuck.

Revvy said:

You can get decent efficiency in partial mashes with an umodified cooler, a grain bag and a folding steamer.

The steamer simply lifts the grainbag above the spigot of the cooler, which creates a bit of a false bottom and also keeps the sparge from getting stuck.

Click to expand...

I have used exactly the same setup, and it works very well. I also recommend it.

budbo said:

I would also try lowering the temp for the dough in. You poured in at a mashout temp.. adding 175 degree water in the beginning probably reduced the diastatic power by killing enzymes before they got started.

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Hey man, how's life? Beers on me the next time you're in town. Anyway, I used this calculator to determine the dough in temp. I was shooting for a mash of 156 degrees, and according to the calculator the strike water needed to be 174. I hit my mash temp almost right on, but is there another way I should have gone about getting there?

FlyGuy said:

I have used exactly the same setup, and it works very well. I also recommend it.

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The cooler that I have at the moment is just a regular square lunch cooler with no spigot, otherwise I probably would have gone that route. And the next cooler I buy won't be a 2 gal, it will be a 10 gal, and I'll convert it to a MLT, and just go straight all grain. Looking to do that by the end of the year anyway.

Ooompa Loompa said:

Hey man, how's life? Beers on me the next time you're in town. Anyway, I used this calculator to determine the dough in temp. I was shooting for a mash of 156 degrees, and according to the calculator the strike water needed to be 174. I hit my mash temp almost right on, but is there another way I should have gone about getting there?

Click to expand...

Life is good I'm in town 8-12 September How's Monday night (8th) sound?

Revvy said:

You can get decent efficiency in partial mashes with an umodified cooler, a grain bag and a folding steamer...I do it all the time with my little 2-gallon cooler, when I don't have a large grainbill and feel like wrestling with my larger cooler...

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Revvy!! You da man!!! I'm gonna mash a 3 gallon batch this week, and I was trying to figure out how I could do it in a small(ish) cooler.. You saved the day.

Ooompa Loompa said:

Gotcha. Makes sense to me now. Thinking back on it now I should have know that, but for whatever reason it just didn't click in my head. Oh well, like I said it was my first PM, and it will still come out just fine, so no worries now. Live and learn as they say.

Click to expand...

It probably still good beer make.

Saccharomyces said:

Revvy!! You da man!!! I'm gonna mash a 3 gallon batch this week, and I was trying to figure out how I could do it in a small(ish) cooler.. You saved the day.

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I do a lot of 2.5 gallon AG batches on my stovetop for tests...Go look about 3-4 pages from the back in the Mr Beer thread for info on my process...I was showing that you can do it and ferment in a mr. beer. I also posted a bunch of scaled recipes..

I prefer doing 2.5 as opposed to 3 gallon batches, because that is exactly 1 case, and it can be fermented in 3 gallon better bottles or water bottles with plenty of headspace. And it is easy for n00bs to scale any 5 gallon batch to 2.5 without software.

I'm going to ferment in a corny keg. I'm trying the pressurized fermentation technique. I could probably go up to 4 gallons.. depends on how much I can stuff into my grain bag.

I really should do another batch in the Mr. Beer. I did a lager in it with my neighbor thought totally rocked... It had enough diacetyl to appease a Red Hook addict though.

So, you're gonna try it huh Sacc? Let me know if you need any questions answered. I love fermenting that way. You should be able to get 4 gallons with no mess at 12-15psi @65*F.