JohnnyO'
Active Member
- Joined
- Oct 13, 2020
- Messages
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- Reaction score
- 24
Posted this on FB - but ICYMI and are interested:
I know that the fellows at Brulosphy have done two exbeeriments relating to crush size. The first one compared 0.039” and 0.025” – which was pretty close to what I wanted to know – and the test did show a big difference in OG for what was supposed to be a large beer (which I do not brew). The second tested 0.030” to as close as he could get his rollers – and showed no difference in OG for a moderate gravity beer. Taken together you can make a good case that from 0.040” and higher down to 0.030”ish – you can realize a gain in efficiency. After that, not so much.
I decided to invest a little time and malt into trying to gauge where I should have my mill (Cereal Killer) set for the beers that are brewed in a lower ABV range. I have been running it at around 0.040”. And my last efficiency (no sparge, no squeeze) was in the low 60s on my Unibrau 10-gallon system. With sparging and squeezing I was getting low to mid 70s. The first beer I ever brewed on the system was before I had my own mill. I asked the LHBS to double mill those grains (mill set at 0.042”) – and ended up missing my OG way high on that batch. So, I also wanted to test the effect of a double crush.
I used 4 batches of 4 oz each Briess Brewer’s Malt and 20 oz of water. One batch single crush at 0.040”, one batch double crushed at the same setting, one batch single pass at 0.025” (lowest CK setting) and one double pass at the same. Each batch was contained in a HD 1-gallon paint strainer and mashed at between 150 and 160F for 20 minutes. I took gravity readings on a refractometer of the wort with no squeezing and then another post squeezing (an estimated 2 oz from the squeeze added back – and ignored the amount of liquid absorbed by the grain). Here are the results for what would be the pre-boil wort gravity and efficiency:
Single Crush, No Squeeze 0.040”
10.3 Brix – 1.041 – 62.33%
Double Crush, No Squeeze 0.040”
10.6 Brix – 1.043 – 65.37%
Single Crush, w/Squeeze 0.040”
10.6 Brix – 1.043 – 72.64%
Double Crush, w/Squeeze 0.040”
10.6 Brix – 1.043 – 72.64%
Single Crush, No Squeeze 0.025”
11.0 Brix – 1.044 – 66.89%
Double Crush, No Squeeze 0.025”
11.5 Brix – 1.046 – 69.93%
Single Crush, w/Squeeze 0.025”
11.0 Brix – 1.044 – 74.32%
Double Crush, w/Squeeze 0.025”
11.5 Brix – 1.046 – 77.7%
The wort collected in the finer crush batches contained a noticeably larger amount of sediment, once left to settle overnight – than did the coarser crush wort.
Later - at the request of someone to throw conditioned grain into the mix I posted this:
https://www.facebook.com/groups/744...meqbaPcqoBen8Y6zQwn6uew8wem1I-Bbc&__tn__=R]-R
"OK Norm, I did the conditioned grain batch. But I do not believe my results - as they are so far off from the others. I'd encourage you to do the experiment yourself. I reset the mill to 0.040" based on the recommendations I read to not mill too finely - so compare these numbers to the appropriate ones above:
No Squeeze - 7.8 Brix - 1.031 - 47.13%
w/Squeeze - 8.0 Brix - 1.032 - 53.97%"
I know that the fellows at Brulosphy have done two exbeeriments relating to crush size. The first one compared 0.039” and 0.025” – which was pretty close to what I wanted to know – and the test did show a big difference in OG for what was supposed to be a large beer (which I do not brew). The second tested 0.030” to as close as he could get his rollers – and showed no difference in OG for a moderate gravity beer. Taken together you can make a good case that from 0.040” and higher down to 0.030”ish – you can realize a gain in efficiency. After that, not so much.
I decided to invest a little time and malt into trying to gauge where I should have my mill (Cereal Killer) set for the beers that are brewed in a lower ABV range. I have been running it at around 0.040”. And my last efficiency (no sparge, no squeeze) was in the low 60s on my Unibrau 10-gallon system. With sparging and squeezing I was getting low to mid 70s. The first beer I ever brewed on the system was before I had my own mill. I asked the LHBS to double mill those grains (mill set at 0.042”) – and ended up missing my OG way high on that batch. So, I also wanted to test the effect of a double crush.
I used 4 batches of 4 oz each Briess Brewer’s Malt and 20 oz of water. One batch single crush at 0.040”, one batch double crushed at the same setting, one batch single pass at 0.025” (lowest CK setting) and one double pass at the same. Each batch was contained in a HD 1-gallon paint strainer and mashed at between 150 and 160F for 20 minutes. I took gravity readings on a refractometer of the wort with no squeezing and then another post squeezing (an estimated 2 oz from the squeeze added back – and ignored the amount of liquid absorbed by the grain). Here are the results for what would be the pre-boil wort gravity and efficiency:
Single Crush, No Squeeze 0.040”
10.3 Brix – 1.041 – 62.33%
Double Crush, No Squeeze 0.040”
10.6 Brix – 1.043 – 65.37%
Single Crush, w/Squeeze 0.040”
10.6 Brix – 1.043 – 72.64%
Double Crush, w/Squeeze 0.040”
10.6 Brix – 1.043 – 72.64%
Single Crush, No Squeeze 0.025”
11.0 Brix – 1.044 – 66.89%
Double Crush, No Squeeze 0.025”
11.5 Brix – 1.046 – 69.93%
Single Crush, w/Squeeze 0.025”
11.0 Brix – 1.044 – 74.32%
Double Crush, w/Squeeze 0.025”
11.5 Brix – 1.046 – 77.7%
The wort collected in the finer crush batches contained a noticeably larger amount of sediment, once left to settle overnight – than did the coarser crush wort.
Later - at the request of someone to throw conditioned grain into the mix I posted this:
https://www.facebook.com/groups/744...meqbaPcqoBen8Y6zQwn6uew8wem1I-Bbc&__tn__=R]-R
"OK Norm, I did the conditioned grain batch. But I do not believe my results - as they are so far off from the others. I'd encourage you to do the experiment yourself. I reset the mill to 0.040" based on the recommendations I read to not mill too finely - so compare these numbers to the appropriate ones above:
No Squeeze - 7.8 Brix - 1.031 - 47.13%
w/Squeeze - 8.0 Brix - 1.032 - 53.97%"