Oat Malt Specifications

[macgruffus]

I did that just to check the pppg of oat malt since I have heard a wide variety of opinions on what figure to use.

Wayne, did you figure out all the numbers you'd need to add the oat malt to ProMash?

Gravity potential? I'm assuming from your post in this thread that it should be 1.047 but that seems pretty high compared to the numbers on Fawcett's website (http://www.fawcett-maltsters.co.uk/specif.htm).

Lovibond? I've seen 4 deg on the Fawcett site.

Can anyone make heads or tails out of their specifications? http://www.fawcett-maltsters.co.uk/specif.htm

[DannyW]

Noonan can help makes sense of it all.

http://brewingtechniques.com/bmg/noonan.html

[macgruffus]

Noonan can help makes sense of it all.

Thanks Danny. Excellent resource. And after I read that, I knew enough to figure out that I could just go into ProMash, change my system settings, and plug the numbers in exactly!

From all that plus a couple more searches I was able to get these figures...



As Bugeater can attest the max per batch can be 100% but I saw some references that more than 20% "can affect the flavor" ... and by that I guess they mean "can make the beer taste like oats"! Not a bad thing in my opinion.

The only thing I'm not sure about is the diastic power so I just took a stab at that one.

David

[Bugeater]

I used 1.033 for the oat malt and think it was a bit high, but then I had a bunch of other problems unrelated to the malt and got pretty crappy efficiency in my mash. I ended up only getting about 60% instead of my normal 75%. I tasted it when I racked it to secondary and it was pretty bland even though it should have tasted overhopped due to higher utilization due to lower gravity. I still haven't finished doing a full write up on the project but will post it when I get it done.

I plan to keg the thing next week and may decide to dry hop the crap out of it with a bunch of Amarillo hops that I need to use up.

Wayne
Bugeater Brewing Company

[jager]

I've gathered a little information about oat malt from emails with Thomas Fawcett.

(I deleted a portion of this post because it was suspected of being false)




Oat malt is under modified ie it has an extremely low S/T ratio (Kolbach index). In an email they listed it as having an S/T ratio of 27.8 (their website lists 30-34) which is probably the lowest of any malt available. European chit malt is the only malt that might be lower but it's not available in the states and I haven't been able to gather any specifications on it.

Index of modification, S/T ratio, Kobach index are all the same thing. They give you a rough idea of how modified the malt is. The more modified the less rigorous your mash schedule has to be.

If you look at the index of modification or TF&S malts you'll notice that the numbers are very low. North American malts are usually in the 45-52 range where a lot of TF&S malts are in the 30's.

You can overcome the under modification by milling it finner than you would normally mill your barley malt or you could undertake a more rigorous mash schedule ie decoction.


Dave

[drewbage1847]

Now that's interesting because that contradicts the information I got directly from James Fawcett when I wrote up my article for Zymurgy a few months back.

Oat malt will self convert and I've done recipes up to 60+% (And they really claim that you shouldn't normally use more than 5-10% if you want clarity.) Bosh!

[jager]

This is Fawcetts reply to someones email.


"Oat malt laboratory worts are normally slightly hazy rather
than clear. Oats are not normally low in protein and are quite
difficult to modify from a protein viewpoint, which could well
explain this. Our current stock gives values of 11.8 % total protein
with an index of modification of 27.8%.

As far as mash schedules are concerned we would suggest you
ensure temperatures are between 63 degrees C and 68 degrees C during
mashing in with a one hour minimum stand after mashing in a grist
composed of 50% oat malt and 50% lager malt.

You should aim at a liquor/grist ratio of between 2.5:1 and 3:1.

Oat malt needs very close mill settings to achieve an
acceptable grist. For normal malts our standard mill setting is 62
thou top and 58 thou bottom- for oat malt we drastically reduce these
settings to 48 thou top and 42 thou bottom. Certainly a point to
watch to produce an optimal grist for mashing."




I had thought that TF&S stated that there wasn't enough enzymes in Oat Malt and that it needed to be mashed with something that did. I was unable to find where they had said that though. So apparently I was incorrect.


Drew, can you post the highlights of the article?

[drewbage1847]

I had thought that TF&S stated that there wasn't enough enzymes in Oat Malt and that it needed to be mashed with something that did. I was unable to find where they had said that though. So apparently I was incorrect.


Drew, can you post the highlights of the article?

Here's what I've got...

The key quote that I've got was in response to a question about using Oat Malt in a high percentage mash...

"We believe that the DP of Oat Malt is sufficient for self conversion
but suspect that it it would not be enough to convert low DP malt."

The rest of the article covers a quartet of recipes:

Mac's Gone Oat Malt Stout
Haver Another AK Mild (I lurve this beer. Hell, I lurve them all, but this one I cycle through on my mild tap)
Amarillo Oater XPA
Brouwerij Van Citters Haarlem Bokbier (The recipe presented in the article is about 50% Malted Oats plus Rye and Wheat malt, but the original brewer has done one up to 75% Malted Oats)