Oats: how much is too much?

As reported, you can brew a 100% oat malt beer as the diastatic power of TF oat malt is above self-conversion threshold but can't seem to find that value currently. Couple things to keep in mind though is that oat malt doesn't have the diastatic power of barley malt, so you can't add as much adjuncts such as flaked wheat or flaked oats. Also it is not as acidic as barley malt resulting in a higher pH mash and finally there is less starch per pound when comparing oat malt vs barley malt, so can't remember if it results in lower yields or higher fg as a result.

So if you want to go bigger with oat malt mixed with smaller amounts of unmalted...just don't go overboard with the unmalted as the Lintner value is considerably lower if I remember correctly.

 

I can't remember who the interview was with, but on one of the BeerSmith podcasts Brad's guest said you want at least 40L for your minimum diastatic power as a mash average. I incorporated this into a spreadsheet I made, but usually try to stay above 50L to be safe.

 

And what value do you utilize for Oat Malt in your spreadsheet?

Cheers!

 

I have done mashes as far down as 25L and got the efficiency and attenuation I was expecting. I'm not saying it's necessarily a bad idea to play it safe, but I wouldn't feel bound by some arbitrary threshold based on what some guy said on a podcast.

 

I did one with 40% and it was horrible squezzing the bag. Ended up with low efficiency of course. The head on the beer were crap and the carbonation was like it was never went into the beer even tho it did. But you should try for yourself for the sake!

 

Did you use oat malt or is that flaked oats?

Cheers!

 

How long did you mash?

I have thought about diastatic power quantitatively since I tried a Munich plus oatmeal stout about 10 years ago. I ended up adding a little 2 row or 6 row for the added DP, but in retrospect, I probably could have mashed longer, or even just let it ride, but the resulting beer did not inspire me sufficiently to give it another try.

 

Vikeman posted a link to this article yesterday in a different thread but it is worth re-linking: http://byo.com/stories/item/621-fabulous-foam

Specifically:

• Fats and oils -- oats, coffee, chocolate, potato chips, and the like all contain fats and oils. Avoid the use of such ingredients if you want good foam. If you want chocolate porter more than foam, then don't worry -- you may get lucky and have good foam.

 

60 minutes. It might be safer to go longer, but 60 minutes has worked for me.

 

My experience with flaked oats and malted oats has been that they are probably "foam neutral" at best. Didn't kill foam but didn't enhance it either as far as I could tell. I suspect that with oats it's a tradeoff between the foam positive proteins and the foam negative oils/fats.

 

I'm with you on this one. I just brewed an IPA with ~16% oats and I'd say I had head for awhile but dissipated pretty quick. I'm looking at throwing some carapils in there to counter act the oils... for some reason I think I'll come up short on that one...

 

If you use malted oats and mill your own make sure to mill at a much smaller gap. Those suckers slide right through at .04

 

late reply but regular store bought oats. dont know what you call that in the us.

 

The type of oats sold in US grocery stores are rolled oats (flaked oats).

Cheers!

@Crusader

 

Hello, in my spreadsheet I take a weighted average of the DP of all the grain/adjuncts based on their contributed %s of the overall bill. If you mean what is the DP of malted oat, well I've never used oat malt (I use flaked), but all forms of oats have a DP of 0 and rely on the diastatic enzymes of the base malts to convert their starches to fermentable sugars.

 

That is incorrect. Oat Malt has Diastatic Power. The question I was asking is what value of DP do you utilize for Oat Malt in your spreadsheet tool.

Cheers!

 

As @JackHorzempa said, Malted Oats have DP. I think the "0 DP" for malted oats myth got started because Thomas Fawcett (a major producer of malted oats) says "Adjunct, 5% - 10% of grist" in their specs. People have successfully made 100% malted oat beers.

Note that we're talking about oat "base malt" here, and not something like Simpsons Golden Naked Oats, which are also technically malted oats but are a crystal malt, so the process destroys the DP.

 

The the Alpha and Beta enzymes (DP) that make the sugars we use to ferment, are the same that are used to convert starch to sugar in the kernel, and the grain embryo then uses for energy. If oats have no naturally occurring enzymes, there would be no oats!

Edit - those enzymes are denatured or destroyed in the hot rolling operation used to make flaked oats and the kilning to make Golden Naked Oats. I agree with Vikeman.

 

IIRC, Alpha Amylase is produced during germination (i.e. malting) and while Beta Amylase does exist in the raw grain, much of it is bound in larger compounds and is released by germination (malting).

 

We have a bag of the TF oat malt in the shop. I was looking at the malt and there is a good about of hull on the oat malt. I was consider doing a 100% oat beer and or a 50%-50% oat malt/wheat malt. I really do not think there would be any sparge water flow issues with the oat malt. I was thinking it may let the water through too fast since there is so much hull. That is where the wheat idea came in the picture.