Author Topic: Naked Oats Info  (Read 322 times)

Offline andyn2001

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Naked Oats Info
« on: March 15, 2019, 03:21:44 PM »
I brewed today with Crisps Naked Oat malt (not Golden Naked Oats, just malted Naked Oats). Two things happened:

I used 5% in a Porter.

1. Mash efficiency dropped by 5%.
2. I ran out of sparge water and came up slighty short in pre boil volume.


So, just wondering, do Oats absorb more water than barley? Also, I added 50g Oat Husks, same question for them. The Oat husks were in the recipe grain bill.

Also, do I need to mash longer, I mashed for an hour as always, is that why efficiency was down?

I used standard infusion mash at 154F
« Last Edit: March 15, 2019, 03:23:47 PM by andyn2001 »

Offline brewfun

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Re: Naked Oats Info
« Reply #1 on: March 16, 2019, 11:17:15 AM »
In my experience, the solubility of oat starches and their conversion to sugar is just about what BeerSmith says it is. Crisp specifications show extraction at 75% typical. I use Thomas Fawcett, which is about 70%. But, in order to lose 5% wort extract from 5% of your grain bill, the oats had to contribute 0%, which isn't plausible.

Oats do absorb a bit more water than barley, because of the increased glucans and protein levels. I'm not sure that's the whole cause of why your volume came up short, but it could have contributed. Oats gelatinize perfectly at mash temperatures.

Pasting is what happens when oats are heated above about 163oF and get stirred vigorously or for a long period of time. The water absorption increases significantly the closer you get to boiling, which blocks water movement through the mash. Some brewers add glucanase to break down the gelatin matrix. I've found that just adding oats near the end of the mash helps lautering and I still get good conversion during recirculation.

The last thing about large percentages of oats (5% doesn't apply, so this is just info) is that the mash pH can rise above 5.6, slowing enzyme activity. That leads to a lot of gelatinized, but unconverted starch in the wort. 

Oat husks don't absorb any more water than barley husks or rice hulls. There's not a lot there to hydrate.
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Offline andyn2001

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Re: Naked Oats Info
« Reply #2 on: March 16, 2019, 11:37:21 AM »
Do I mash long enough, 1 hour? Should I increase to 90mins?

Offline brewfun

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Re: Naked Oats Info
« Reply #3 on: March 17, 2019, 07:50:26 AM »
Possibly. Not because you need more conversion, but because the wort may not be as saturated as it could be.

I use a refractometer to watch first wort gravity during recirculation. When it stops rising, then I'm ready to sparge. I'm usually looking for 21 to 24 plato (1.083 to 1.100). This is an especially good strategy for batch sparging if someone is looking for more efficiency.

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Offline Oginme

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Re: Naked Oats Info
« Reply #4 on: March 17, 2019, 07:55:23 AM »
Oat malt is a lot thinner than barley malt and should be milled separately with a narrower gap.   If you milled this grist together (or had them milled), I would highly suspect that you did not crush the oat malt enough to realize their potential.

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