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-   -   *$&%*$ Efficiency (http://www.homebrewtalk.com/f36/efficiency-49170/)

ohiobrewtus 12-27-2007 11:53 AM

*$&%*$ Efficiency
 
I normally hit about 75% efficiency with all of my brews and until I can get a BC and do my own I'm happy with the crush that I get from AHS, but the last 3 brews I've done were just weird.

I did an Amber with a TG of 1.060, I missed my target volume so I only had 4.5g into the fermenter causing me to have to top off, but I missed my OG by 13 points - 58%

Then I did an IIPA with a TG of 1.093. Preboil was 1.068 so I added 1 lb. dextrose. I hit my volume but ended up at 1.082 - 66%. I really wanted this one to be higher in alcohol to balance out the 12 oz of hops that were in it so I cooked up .5 gal of 1.080 wort with DME and pitched after 3 days. (Two packets of rehydrated Nottingham dropped this from 1.082 to 1.016 in 36 hours)

Then I did a sweet imperial stout. I took into account the sucktitude of the last 2 mashes and went into beersmith a dropped my estimated efficiency to 65% giving me a TG of 1.072 - 11 points lower than the 1.083 that 75% would have given me.

I decided to mash this one for 75 minutes rather than 60, with no other changes in procedures or equipment. I ended up with a full 6 gallons in the fermenter at 1.090 for 88.66% efficiency.

Could the additional 15 minutes of mash time really have made that much difference? I could see it improving efficiency a bit, but not this much.

It's been driving me crazy as to why the two brews above were so low. I've been through all of my notes and I can't pinpoint anything in particular that would have caused it. Could a poor crush be responsible for most of the deficiency of these two batches?

Orfy 12-27-2007 12:02 PM

I was brewing consistently in the mid 80's and I changed the supplier of my pre crushed grain.
My effieciency dropped to mid 60's, nothing else changed. It took me a few brews to dial in the new figures so I just brew with more grain. No biggy, the grain was half the regular price.

It's about consistency.

Kaiser 12-27-2007 12:04 PM

Quote:

Originally Posted by ohiobrewtus
Could a poor crush be responsible for most of the deficiency of these two batches?

It could have as you are not crushing your own grain. Also, do you check for conversion? Maybe your water chemistry was off. But the latter is an unlikely source of your problem if you have brewed similar beers with good efficiency before.

Kai

jdoiv 12-27-2007 12:04 PM

Are you testing for conversion? If not, then the additional 15 minutes may have had something to do with it. Also, from what I have found, the higher the gravity I'm shooting for, the lower the efficiency. The only way to really up the efficiency, for me at least, on high gravity beers is to sparge longer and boil longer. Could be the Amber was just not converted.

ohiobrewtus 12-27-2007 12:22 PM

I currently do not test for conversion, as I was happy with 75% using someone else's crush. I will see how the next few brews go and if I continue having this issue I'll begin testing for conversion - and add a couple more pounds per recipe.

Chriso 12-27-2007 01:33 PM

I didn't test on my first 3 or 4 batches, now I do every time. My gravities have been much closer to TG since using it. For two bucks, Iodine lasts ages and ages, and is a great test tool that keeps me from sparging too early. Highly recommended.

brewt00l 12-27-2007 01:55 PM

Quote:

Originally Posted by ohiobrewtus
I normally hit about 75% efficiency with all of my brews and until I can get a BC and do my own I'm happy with the crush that I get from AHS, but the last 3 brews I've done were just weird.

My last few batches from AHS w/ their crush have been all over the place too. The first two or three previous batches exhibited a drastic reduction in efficiency. The last one was crushed too fine and resulted in a massive stuck sparge. I was satisfied with their crush before these batches..now, I am not so.

fifelee 12-27-2007 02:13 PM

How old was the grain that got good efficiency versus the poor efficiency?

Another possible theory.... I have been wondering if efficiencies will start taking a hit from poorer ingredients. Because of the grain shortage the malt companies have been calling the farmers in our area looking for barley. My father had some that was only suitable for feed in past years, but this year they gladly took it.

ohiobrewtus 12-27-2007 02:23 PM

Quote:

Originally Posted by fifelee
How old was the grain that got good efficiency versus the poor efficiency?

Another possible theory.... I have been wondering if efficiencies will start taking a hit from poorer ingredients. Because of the grain shortage the malt companies have been calling the farmers in our area looking for barley. My father had some that was only suitable for feed in past years, but this year they gladly took it.

The malt I used in the Amber was crushed about 14 days before I used it. The other two batches were crushed less than 6 days before being used.

Reverend JC 12-27-2007 03:00 PM

Make sure the thermometer is calibrated. I used one i thought was right for three batchs until i realized it was off five degrees and that caused my eff. to take a dump on me into the upper 50s. back to the original thermometer and im back to 78% eff.


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