Horrible efficiency - is it the recipe?

I've been averaging efficiency into the boiler in the 80% - 83% range for several brews now, but tonight I threw in a real stinker - 68%

The recipe is a new one I put together - an oatmeal stout. It has way less base grain per pound of specialty grain than I've ever used before. I'm wondering if I don't have enough for conversion??

Recipe:
6 lbs UK 2-row
2 lbs Crystal 60
2 lbs flaked oats
1 lb cara-pils
3/4 lbs roasted barley
1/2 lb chocolate malt
and then about half a pound of rice hulls.

I mashed 15.5L at 158 for 45 minutes and mashed out at about 168 with an additional 6+L for a few minutes before draining, then sparged with 3.5 gallons of 175ish water. I hit all the numbers, but initially the mash temp was high - about 162. I stirred and got it down in about 5 - 7 minutes or so. I did not add cold water.

I was shooting for 1.048 into the kettle and got 1.041. I'm boiling now.

Any thoughts?

Brewhouse efficiency clocked in at just over 57%. Awful I've been getting 68% - 70%.

It is also more of a dark brown than the black color I was hoping for.

On the bright side, I may have made a very good Bare Knuckles clone:fro:

Your grain bill looks fine, that should convert OK. First thing I'd look at is your crush. To me that seems to be the biggest contributor to efficiceny suckage. You say this is your first recipe on your own, have you been buying kits before?

Quit stressing on the efficiency. Just do the best you can on each brew.

EvilTOJ said:

Your grain bill looks fine, that should convert OK. First thing I'd look at is your crush. To me that seems to be the biggest contributor to efficiceny suckage. You say this is your first recipe on your own, have you been buying kits before?

Click to expand...

It's the first time with this recipe, but I've done several of my own. I'm pretty sure it isn't the crush, although I can't say I'm absolutely sure. The only thing really different other that the base/specialty ratio is rice hulls. I've never used them before. I'm at a loss.

Oh well, at least I get to try again I'm working my way towards a standard house stout. This is version/tweak #2.

you used a fairly high mash temp but on its own I dont think that would do it. maybe the water chemistry and Ph was off. did you do an iodine conversion test?

The important thing is that it's a one time fluke. Since you regularly and consistiently get higher numbers, I wouldn't sweat this one.

Double check your crush next time, otherwise, keep doing what you're doing since it works well.

I just got a 59% eff into primary. Grrr

I have been hitting 69-71% with the last 3, and this IPA is exactly as I did before. I don't get it.

This stuff is going to have to age a while... 1.052 OG and 78 IBU. Don't think I'll even bother tossing 2 packs of US-05. One should be fine.

Arrrrgggghh.

I adjusted my gap tighter on the BC, hoping I'd go up from the 70% with the stock setting. I definitely closed the gap, but the eff. went down. Guess I'll go back to original setting and see what happens on the next batch.

Stinking hot in my garage too, so I'm sweaty and mad.

With that high of an adjunct to base malt ratio, I would have mashed longer or used 6-row