Malted Oats

[Jeltz]

Do those who use rolled oats do a glucan rest or just dough in dry with the rest of the grain at the start of the mash?

[WishboneBrewery]

Just let it mash for a little longer, 90 should be fine and I normally do 60-90mins.

[raiderman]

Ah well, I've just mashed 200g of malted oats with around 6kg of Belgian pale rounded off with willamette and simcoe.

[jonewer]

So could I make a mash of 2 kg oat malt, 2kg rye malt, 0,5kg rolled oats and 0.5kg torry wheat? Or would this be a recipe for a stuck sparge?

[seymour]

So could I make a mash of 2 kg oat malt, 2kg rye malt, 0,5kg rolled oats and 0.5kg torry wheat? Or would this be a recipe for a stuck sparge?

Yes, it would be a very sticky mash. Including rice hulls or oat hulls would help. I would also recommend a substantial portion of Maris Otter or Six-Row Pale...some kind of high enzyme pale malt which is better equipped to convert the non-malted ingredients, leading to a much higher efficiency overall. I like the way you think, though. Best of luck!

[zgoda]

German made rye malt has diastatic power comparable to pilsner, it will easily convert additional 50% of its weight adjuncts.
With that high amount of rye and oat malt stuck sparge is to be expected. I doubt any husks could help here, because the problem comes from high wort viscosity.

[jmc]

So could I make a mash of 2 kg oat malt, 2kg rye malt, 0,5kg rolled oats and 0.5kg torry wheat? Or would this be a recipe for a stuck sparge?

Yes, it would be a very sticky mash. Including rice hulls or oat hulls would help. I would also recommend a substantial portion of Maris Otter or Six-Row Pale...some kind of high enzyme pale malt which is better equipped to convert the non-malted ingredients, leading to a much higher efficiency overall. I like the way you think, though. Best of luck!

It would be interesting to see if a stepped mash with a Glucan rest (37-46C) would reduce glucans and viscosity

See extract from Palmer's How to Brew - 14.4 The Protein Rest and Modification

The other enzymes in this temperature regime are the beta-glucanases/cytases - part of the cellulose enzyme family, and are used to break up the beta glucans in (un)malted wheat, rye, oatmeal and unmalted barley. These glucan hemi-celluloses (i.e. brambles) are responsible for the gumminess of dough and if not broken down will cause the mash to turn into a solid loaf ready for baking. Fortunately, the optimum temperature range for the beta glucanase enzyme is below that for the proteolytics. This allows the brewer to rest the mash at 98 -113°F for 20 minutes to break down the gums without affecting the proteins responsible for head retention and body. The use of this rest is only necessary for brewers incorporating a large amount (>25%) of unmalted or flaked wheat, rye or oatmeal in the mash. Sticky mashes and lauters from lesser amounts can usually be handled by increasing the temperature at lautering time (Mashout). See Chapter 17 - "Getting the Wort Out - Lautering" for further discussion.

When I do wheat beers I follow a 40 50 62 68C step mash with the first step primarily to reduce glucans.
Typically wheat beer I do would have 37% unmalted flaked wheat & oats, but I find I don't need to add rice/oat hulls as long as I use the 40C step.
I don't have a problem with (batch) sparging with a simple copper manifold.

It really amazes me each time watching the wort colour / opacity change in these lower steps as the enzymes kick in.
Example wheat beer recipe
Lager Malt, Flagon 2.7 EBC 2000 36.7%
Flaked Wheat 4 EBC - UK2 (bal) 1500 27.5%
Wheat Malt 3.5 EBC (bal Uk1) 1000 18.3%
Oat Flakes 2.5 EBC - UK2 550 10.1%
Cara Munich II 120 EBC - Non-UK1 (bal) 200 3.7%
Acid Malt 2.5 EBC - Non-UK1 80 1.5%
Carabelge 300 EBC - Non-UK1 70 1.3%
Cara Munich III 150 EBC - Non-UK1 50 0.9%


Pics below from Saison #2 - AG78 (+ pics)

Recirculation at 40C . Ratio 1.9:1. Really thick at this stage

No pic recirc at 50. This at ~ 62C. Final ratio 3.5:1. Almost clear at this stage

The 40C step breaks-down loads of the glucans from wheat & rye, so no need for oathusks / rice hulls.
Run off was fine.

[6470zzy]

With that high amount of rye and oat malt stuck sparge is to be expected. I doubt any husks could help here, because the problem comes from high wort viscosity.

You will have a tendency for a stuck mash when using a good portion of Rye Malt I agree, however with Oat Malt there is no such problem whatsoever. Oat Malt has loads of husk material.

Cheers

[zgoda]

Except that German made oat malt (e.g. Steinbach) is huskless.

[6470zzy]

Except that German made oat malt (e.g. Steinbach) is huskless.

Thanks for that information. I am unable to purchase that brand here (apparently good for me )

I use Thomas Fawcett & Sons ......maybe we all should

Cheers

[TC2642]

Clive La Pensee's recipe for Oat Ale is as follows

1/2kg Pale malt
1 1/2kg crushed Jumbo oats
1 Gal soft water
30gms Goldings.

He suggests starting off at 35oC and leaving it to stand for two hours before ladling off a third of it and bringing it to the boil then returning it to the mash so the temp gets to around 70oC. Sparge until you get around 3 1/2 gals and boil with hops for 15mins. Ferment as usual.

Sounds interesting but I may do as Seymour suggested and do about 1/3 oats to 2/3 pale malt with a full boil for 60mins. I would step mash this though.

[raiderman]

The idea has now made it into the pubs. I was drinking Siren Crafts Under Current Oatmeal Pale Ale on Thursday at the craft beer co. Excellent brew.