Questions on milling grains

[CJ-3]

Hi all,

I have three questions on milling grains at home as opposed to buying ones pre crushed/milled.
1) the grain shell just needs to be cracked open, as opposed to actually grinding the grains - is this correct?
2) i see people list their 'efficiency' in ranges from 60% to 90% how do you measure the efficiency of your milling?
3) in my readings I saw that some grains, such as black malts, should never be milled - is this also correct?


Any help with this is appreciated as I am getting confused.

 

[Oginme]

1) you are correct. An ideal crush has the hulls nearly intact and the kernels inside crushed into particles less than 1/8".

2) Efficiency is a misleading and often misused term.

There is extraction efficiency, which is the amount of sugars extracted from the grain compared to an expected amount. This is done by comparing the ideal points per pound per gallon (ppg) of the grains times the amount of grain times the volume to the volume of wort produced times the specific gravity of that wort before lautering. Most people do not actually measure this value.

Next is lauter tun efficiency, which is a measure of the ideal amount of sugar to the actual amount after removal of the grains. This is calculated using the ideal amount of sugars as calculated above as compared to the volume of wort after lautering times the specific gravity of the lautered wort. The difference between this calculation and the previous one is the realization of volume loss of fluid to the grain absorption and any dead volume of the lauter tun. This number is more useful to brewers as it represents the actual usable amount of removed sugars from the grains.

After that is efficiency into the fermentor, which is the actual amount of sugars that make it to the fermenting vessel. It is calculated similarly to the efficiency numbers above, but uses the volume of the wort into the fermentor times the specific gravity of the wort as compared to the ideal value.

3) Never say never. If you are looking for color only and very little taste impact, you may wish to leave your black or highly roasted malts intact. On the other hand, you are giving up some of the fermentable materials that are in the malts. Personally, I mill my black malts to get what I can out of them. If I don't want the highly roasted taste, I grind them to flour and sprinkle on top of my grains just before I sparge.

 

[cabron99]

Uh...what he said.

 

[CJ-3]

Thank you!

That makes it much easier to understand. I think I was on research overload and I was confusing myself.