Specialty Grains for Extract Brewing

Hello,

I have a question regarding the use of specialty grains for extract brews. Particularly, how do you calculate OG and color contributions for specialty grains? I've seen some other threads suggesting that specialty grains do not contribute to the OG, but this is incorrect since they do contain non-fermentable sugars even though there is no enzymatic activity occurring.

I've also seen some numbers that indicate steeping has an extraction efficiency on the order of 20-30%, so the formula for point contribution should be something like:

Points =

[Grain weight * Grain ppg * steeping extraction efficiency]/Boil volume

The efficiency should be a function of steep time, temp, and grain crush size, but I'm just wondering if there is any empirical data that could be used to calculate steeping efficiency as a function of these variables, or do I just assume something like 30%?

Also, this efficiency should just be in regards to sugar extraction; is there any other correlation to color contribution? Or is it assumed that the color contribution is 100% efficient? I'm using

Grain weight * Lovibond rating to get MCU, then using Morey's formula to estimate SRM.


Any help would be much appreciated!

I've never seen people claiming that specialty grains don't impact gravity, but if you have they are - as you say - incorrect. Some of the sugars in them are fermentable, too. There's a good thread around here comparing the fermentability of a bunch of different crystal malts.

20-30% sounds about right to me, and I doubt you are going to find more precise numbers than that as your extraction efficiency would depend significantly on the conditions of your set up. If you'd like something more precise and specific to your system, run a quick test. It should be easy enough.

I would be very surprised if sugar contribution extracts at 30% efficiency but color contribution does at 100%. It is possible that color compounds are extracted selectively, but not to that degree. If I had to guess, I would likely assume that color contribution is more in line with the 30% extraction rate. That jibes with my anecdotal experience, at least. In any case, this too could be tested if you wanted more precise numbers.

There are some numbers on specialty grain color and ppg on CP's brew chart.

https://www.homebrewtalk.com/f14/cps-brew-chart-2-0-a-221089/

Thanks for the feedback. Looks like I'll need to do some testing in my kitchen, but that gives me an excuse to brew some more (not that I needed the motivation).

Do you happen to know what the actual color compounds in malt are? If they are similar to sugars in molecular weight and solubility, then yes, I agree that they would diffuse into the steeping water at a similar rate.

Trial and error can be a lot of fun, but if you want a more direct route, check out Beer Smith or similar software.

mplsbrewer said:

Do you happen to know what the actual color compounds in malt are?

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Hmm...not off hand. I read an article a while ago that listed some. I think it was by Charlie Bamforth. Two that pop into my mind would be melanoidins in some toasted malts and burnt carbon in roasted malts.

Also check out Qbrew. It is a nice free software to use to start out with.

The percentage you'll get from the grain will depend on the method and volumes of water you use to steep and rinse the grain. 70% should be doable using the dunk method; i.e. steep in a certain volume of water for awhile, then dunk for several minutes in a similar volume of clean 160ish water. Obviously combine the 2 volumes, then add your extract and boil as your process requires.

Frodo said:

The percentage you'll get from the grain will depend on the method and volumes of water you use to steep and rinse the grain. 70% should be doable using the dunk method; i.e. steep in a certain volume of water for awhile, then dunk for several minutes in a similar volume of clean 160ish water. Obviously combine the 2 volumes, then add your extract and boil as your process requires.

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Interesting. I've never seen anything close to 70% extraction. Do you have a source?

MalFet said:

Interesting. I've never seen anything close to 70% extraction. Do you have a source?

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Is what I described much, if any, different than batch sparging? That's where I got the 70% from.

Frodo said:

Is what I described much, if any, different than batch sparging? That's where I got the 70% from.

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At least some specialty grains are not completely converted by the maltster, and thus use the diastatic power of the base malts they are mashed with to convert starches to sugars. In that instance, steeping wouldn't work. I'm now sure how this applies to different kinds of specialty grains, but I wouldn't say that what you are describing is the equivalent of batch sparging because steeping isn't the equivalent of mashing.

I wasn't talking about mashing. I was talking about rinsing the sugars from the grain a.k.a. sparging. If you dunk a bag of grain that's been partially mashed or steeped, that's a rinsing (sparging) process. I was assuming that the proper method would be used for whatever particular specialty grain used; i.e. if it's a malt that needs to be mashed that it would be included in a partial mash process with some base malt, and if it doesn't need to mashed to convert starch (eg. crystal malts) then steeping would be sufficient.

Frodo said:

I wasn't talking about mashing. I was talking about rinsing the sugars from the grain a.k.a. sparging. If you dunk a bag of grain that's been partially mashed or steeped, that's a rinsing (sparging) process. I was assuming that the proper method would be used for whatever particular specialty grain used; i.e. if it's a malt that needs to be mashed that it would be included in a partial mash process with some base malt, and if it doesn't need to mashed to convert starch (eg. crystal malts) then steeping would be sufficient.

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I understood that. And I certainly understand that dunking a grain bag in water is a rinsing process (give me a little credit here, ya? ) The point of yours that I was objecting to, specifically, was the claim that you can expect the same extract efficiency (70% is the number that you used) from steeped specialty grains as from mashed specialty grains. While the rinsing process might be the same for mashing and for steeping, a steeped grain doesn't have as many simple sugars to rinse off in the first place. Even with the same grain, mashing converts starches that steeping doesn't.

This idea that crystals, etc. are "pre-mashed" gives too strong of an impression. While the malting process of some types of specialty malts converts _some_ of the starches into things extractable by steeping (and thus useful to extract brewers) not all of the starches are actually converted when they leave the maltster. These unconverted starches represent a hard upper limit to your potential extraction without enzymatic mashing. While what you are describing is mechanically the same as a batch sparge, there just aren't as many sugars to rinse off.

The extent to which this happens certainly varies from malt to malt; a crystal-120 likely needs less help than a crystal-20. A honey malt, a special B, or a Munich needs a lot of help. The 30% that gets tossed around is a loose and fast average, but in my experience it's generally going to be a lot closer to the right answer than 70%.

There's an essay I read a while ago by Charlie Bamforth that explains this better than I can, but I can't for the life of me find the reference right now. Here's another article that says something similar.

I didn't see anything in the article indicating extract efficiencies in the 20 to 30% range, but easily could've missed it since I just skimmed. Either way, doesn't really matter to me enough to debate it. I re-read the OP though, and realize I threw out that 70% number and talked about rinsing the grains, thereby pulling some lauter efficiency discussion in and confusing the issue which was not intended... I realize the OP was in regards to extract efficiency. I seem to be in the 90% extract efficiency range when mashing; but that's with heaps of base malt though so not really comparable to steeping so much if there are starches to be converted in the specialty grains. If you have literature citing 20 to 30% extract efficiencies when steeping then obviously that's better info than my WAG 70% reply.