Bad crushing responsible for 55% eff. ????

What went wrong? Was this supposed to happen? Should I throw it out? What do I do now?

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kabbo
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Bad crushing responsible for 55% eff. ????

Post by kabbo »

Hello. I'd like to know if an inadequate crushing can have such an impact on extraction or if I did something else wrong !

Just did my first all-grain today and everything went very well exept for the resulting OG. The traget was 1.047 (75% efficiency calculated in BTP) and I got 1.034 which represents around 55% efficiency !!!!

I'm pretty sure the grain was not cracked enough so it couldn't expose enough sugars in the mash. The recipe contained wheat malt which is supposedly pretty hard and when the grain got crushed at the HBS, they mixed all the grains together before cracking it. The other grains were ok but the wheat malt was almost untouched... But it was too late, the grains were mixed together and crushing them a second time would have probably get the pils malt into powder... :x arrg....

Here's a detail on my recipe, setup and techniques used.
I was doing a Belgian Witbier 6 gal recipe :
5 lbs German Pils
5 lbs Wheat Malt
1.1 lbs Flaked wheat

Equipment:
10 gal round beverage cooler
Copper manifold (carefully designed following John Palmer's rules..)
Gate valve for lautering flow control
Split boiling in two 5 gal brewpots on the stove
2 immersion wort chillers

Procedure :
Seperated 20 mins. protein rest (100F) for the Flaked wheat in 2 quarts of water
Added strike water and grain and flaked wheat into cooler, mixed everything together, 1.5 qt/lb ratio
20 minutes 141F
Grainbed was 6-8 inches, pH seemed to be between 5 and 6 (pH test papers...), stirred every 15 minutes to help extraction and prevent cold spots
Water chemistry was calculated in BTP, nothing over standards
50 mins 153F (added 4 quarts boiling water to reach this
Decoction mashout, removed 6 quarts (only liquid) took 10-15 minutes to reach boiling temp and returned to mash to reach 170F (I did this to avoid stuck sparge)
Recirculated 3 times (3 qts)
Started sparge at a approx. 1qt/min rate
When only 1 inch left over grainbed, started adding 170F sparge water (previously treated with phosphoric acid to reach around 5.5-6.0 pH)
Lautered to collect the needed 8 gals of wort.
Runoff started to be very clear when I had only 4-5 gals so I continued even tough it was looking like water, cause I needed the 8 gals to do the batch.
I was careful not disturbing the grainbed when adding sparge water (coffee lid trick).

I don't think I sparged too quicly because it took about 45 mins to collect the wort. Should I have stirred more often ?? Could that be the cause of 12 gravity points under what expected ??

I hope it is only the crushing since it can be done better for the next recipes and I don't have to change my equip and/or techniques.

So is the bad crushing responsible alone for 12 gravity points lower, or I did something wrong in the techniques ?

Thanks a lot guys !
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Push Eject
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Re: Bad crushing responsible for 55% eff. ????

Post by Push Eject »

First of all; GREAT TECHNIQUES.

You are describing a first-rate brew session and obviously know what to look for and what you are doing (I haven't bothered checking my pH in years).

I really think your crush is responsible for your lower than expected efficiency. Truth be told mine is usually 65%, but 55 does seem pretty darned low.

Reading your post there aren't many other variables to consider. Your process was sound, IMHO.

Our of curiosity, was the wheat malted or flaked?

However, if you aren't going to crush your own (I don't either) consider uping your grain bill or keeping (ugh) extract around to boost a low OG if needed. Grain is cheap and could keep you using your LHBS's mill for years.

How's the batch taste?

Cheers,
Charlie
kabbo
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Re : Bad crushing responsible for 55% eff. ????

Post by kabbo »

Thanks for the reply.

I'm glad to hear my techniques are good, I was kind of concerned and discouraged.

To answer your question about the wheat, there was 50% german pils, 50% malted wheat (almost uncrushed...) and 1lb of wheat flakes.

The beer seems to ferment well and smells awesome. I tranfered to the secondary after 7 days and acticity increased (like a new primary). It has been 24 hours and bubbling is still steady, I think and hope it will get down soon for secondary.

I will try another recipe next week, this time no wheat, just crushed malt and some flaked rice. I will then have a better idea of my real extraction rate.

I will keep some DME just in case I need to boost the OG.

Thanks a lot !
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Push Eject
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Re: Re : Bad crushing responsible for 55% eff. ????

Post by Push Eject »

If you are considering adding DME why not just throw 25% highly-modified (North American) two-row in the mash. The enzymes are SCREAMIN in those things and will give you a big boost all around.

Cheers,
Charlie
kabbo
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2-row

Post by kabbo »

Thanks for the advice,

I will try without DME for the next batch, to know exactly my natural extraction rate, I will then see if I should use more grains in the future to achieve the target OG.

I'm pretty confident about the next batch, I will try to sparge more slowly and to correct the pH with precision, and I'll be really careful about heat loss and keeping the exact temp for the conversion.

I'll let you know,
Thanks again Charlie,

Kabbo
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