Predicted OG 1.069 - Measured OG 1.054! Why?

[jmacker]

If anyone has any ideas about why my eficeincy was so bad today, and how I might salvage this beer, I would love to hear...

I just wrapped up a brew day for 10 gallons of a rye IPA. The grain bill was:

14 lbs Pale Ale Malt
4 lbs Rye malt
3 lbs C-60 (too much I think but it's the least of my problems)
2 lbs Carapils
1 lbs Aromatic

I checked my mill gap and it is a little bigger than I expected - .042" instead of .037".
I measured the OG with a refractometer which I then checked the calibration and it is good. I also used a hydrometer and got the same reading.
I had to mash a little thick at 1:1.19 instead of my normal 1:1.33.
I mashed at 150 for 60 minutes. Double batch sparge with 170F water to get 11.5 gallons of preboil wort.

I just can't imagine why my efficiency suffered so much. I was expecting around 74% and it looks like I may have ended up with something like 24%!

The original recipe had calculated IBUs of 63. Now I don't know what it will be. It is bittered with Pearle and the rest Amarillo at 30, 10, and whirlpool. Planning to dry hop to but at this point I don't know what to do.
I have already pitched some S-05 (since my conan starter was another fail today). Does it make any sense at this point to try to add some malt extract to one of the 5 gallon buckets to try to salvage this batch? btw I've already tried to RDWHAHB. No luck there either.

 

[kh54s10]

The crush probably had some effect on the result. Did you end up with the proper volume? If you ended up with too much it didn't concentrate enough.

You might also have to check the amounts of loss you get with your system. If you lose too much (wort left in the tun) is may lower the efficiency.

You could make up some extract wort and add it to the fermenter. It will change the recipe, although it is already not as intended.

For me I would leave it alone and try to adjust things so the next one is closer. The result will be beer. It will not be as high in ABV as the recipe called for but I would wager it will be good. (If your previous brews were good.)

 

[jrgtr42]

I don't know much about efficiency, but my back of the hand math doesn't quite put it at 24%...
Presuming you ended up with around 10gallons going in, it's mid - 60s somewhere, I would presume.
I think that it's a combination of all of the above factors that brought your OG down. The 3lbs of the c60 probably didn't change it much compared to an equivalent weight of 2row, it's more the unfermentables that would create.
More so the rougher crush and thicker mash are the biggest factors IMO. Mash temp and length is fine, as long as you confirmed conversion, I will also presume you know your equipment that 1.5 gal of boiloff is right.

 

[jmacker]

You're right about the efficiency. I originally got the 24% from messing around with brewtoad until it hit my measured OG. I never bothered to calculate it.
That honestly makes me feel a lot better.
Thanks for the replies and for talking me down from the ledge. This homebrewing stuff gets pretty intense.
Once again looking forward to my next batch and the many small adjustments I need to make to improve.

 

[RM-MN]

So you have a lot of experience with rye? The kernels are smaller and harder than barley so even if you had your crusher set right for barley it won't crush the rye as well as it should. I just ran into that with a roggenbier and I use a Corona style mill set as fine as I can get it (BIAB lets me have a very fine crush/grind). Since I crank my Corona mill by hand it was really obvious how much harder the rye was.

 

[dankbeer]

Jmacker, I found this information very helpful when it comes to questions about efficiency with a single infusion mash: http://braukaiser.com/wiki/index.php?title=Effects_of_mash_parameters_on_fermentability_and_efficiency_in_single_infusion_mashing.

His results suggest your gap settings for milling the grain reduced your efficiency, but the thick mash most likely had no effect on efficiency.

Hopefully that page helps you out.

Cheers!

 

[stevehardt]

I agree that your crush was at least a part of the problem, especially with a rye.

Was your wort evenly mixed when you took a reading?

 

[EarlyAmateurZymurgist]

Even if you were using all base malt and the analyzed maximum hot water extract for the bag of base malt was 36 points per pound per gallon, your extraction efficiency would be better than 24%.

total_gravity_points = (1.054 - 1.0) x 1,000 x 10 = 540

total_volume = 10 gallons

extraction_rate_in_points_per_pound_per_gallon = 540 / 24 = 22.5

extraction_efficiency_as_all_base_malt = 22.5 / 36 = 62.5%

As we all know, specialty malts tend to have lower maximum hot water extraction rates; therefore, your actual efficiency was higher than 62.5%.

With that said, did you ensure that there were no dough balls in your mash? Did you check to see if conversion was complete?

 

[chri5]

Its almost always due to the crush from my experience. Tighten that gap and you should be good.

 

[JLem]

I've never used rye, but whenever I use a large proportion of wheat my efficiency drops. I have narrowed it down to the fact that the smaller, harder wheat malt doesn't get crushed as well as the barley.

 

[Stubblejumper]

I run ry through the mill 2 or 3 times first on its own. A protien rest wouldnt hurt either.

 

[jmacker]

I agree that your crush was at least a part of the problem, especially with a rye. Was your wort evenly mixed when you took a reading?

I took several different readings just to be sure it was accurate.

 

[jmacker]

I have adjusted the gap on the mill so I hope to be back in the 70s with the next batch. Maybe next weekend I'll put a 5 gallon batch together and see what happens.

Thanks again to everyone for the replies.