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Mashing malted oats

PostPosted: Thu Jan 03, 2019 20:13
by jonnymorris
Hi,
I've been absent from this forum for a long while so, hello again fellow brewers. :cheers:

I'm planning an Oatmeal Pale Ale that calls for 625g of malted oats which amounts to c.15% of the grain bill. I've not brewed with oats before so am wondering if I'm going to have problems when it comes to the sparge... i.e. do I need to include husks to avoid a stuck sparge as I would with a significant amount of wheat?

Grain bill
Maris Otter 3,195g
Malted Oats 625g
Wheat 312g
Carahell 312g
CaraAroma 48g

Thanks,

Jon

Re: Mashing malted oats

PostPosted: Sat Jan 05, 2019 11:58
by jonnymorris
For what it's worth, I included 150g of oat husks in the mash and had no problems at all with the sparge. Don't know if they were necessary but better safe than sorry.

Re: Mashing malted oats

PostPosted: Tue Jan 08, 2019 23:59
by john luc
Building an Oatmeal stout recipe ATM and was wondering if you had considered using toasted oats in this brew. :hmm:

Re: Mashing malted oats

PostPosted: Wed Jan 09, 2019 10:54
by PeeBee
I'm planning on a recipe with 850g "naked oat malt" (Simpsons) in a 20L batch and have 1Kg of oat husks to add! But then it has 2.2Kg of rye malt too. Guess its going to be stodgy. It's this recipe https://www.themadfermentationist.com/2 ... u.html?m=1.

I'm trying the recipe to add a few more ideas to my "low-alcohol" brewing repertoire. As it stands at about 2% ABV it doesn't fit in with what I call "low-alcohol" (i.e. <0.5% ABV) but it has a few ideas to try. I was going to use BIAB techniques, but as I've just acquired a Grainfather I'll use that (using 3.5L/Kg mash thickness instead of the usual 2.7, and probably not fitting the top perforated plate 'cos there won't be enough grain to support it, and skipping the "sparging").

Re: Mashing malted oats

PostPosted: Sat Jan 12, 2019 20:26
by PeeBee
"Beer" done! Actually at 5.6L/Kg (very dilute; full brew length's water in mash so no sparge) and top perforated plate used by fixing to the GF overflow pipe with a hose clip ('cos there wasn't enough grain to support the top plate). The top plate diffused the recirculated wort and so couldn't dig up the grain bed; or that's what I guessed would happen so I opted for not doing without the plate.

There was no suggestion of the mash being excessively stodgy (there was 20% oat husk added). Perhaps this gummy oats (and rye) suggestion is a bit exaggerated?

Re: Mashing malted oats

PostPosted: Sun Jan 13, 2019 13:22
by john luc
there is a micro pipe you can get for the grainfather to allow for smaller grain bills

Re: Mashing malted oats

PostPosted: Sun Jan 13, 2019 18:06
by PeeBee
john luc wrote:there is a micro pipe you can get for the grainfather to allow for smaller grain bills

I know, I've got the "micro pipe". I was sort of emulating a BIAB technique 'cos the means of heating a sparge quantity of water is "off-line" just now. And I had heard horror stories about brewing a 100% rye and oat beer. It's a "lower alcohol" batch to try some new techniques before brewing my next "low alcohol" batch with the micro pipework ("low alcohol" is 0.5% ABV to me, whereas this oat and rye batch, which mashed so successfully, is predicted to be over 2% ABV - err, I do brew real beers too). Cheers.

Re: Mashing malted oats

PostPosted: Sun Jan 13, 2019 23:16
by john luc
interested to hear how you get on with your low alcohol beer

Re: Mashing malted oats

PostPosted: Tue Jan 15, 2019 01:13
by PeeBee
50 hours on and my "low(-ish) alcohol" beer has started showing signs of ferment. Now my "is it doomed" anxiety is replaced with worrying "will it explode before I get up in the morning?". I guess all my low-alcohol brews are a bit tardy getting going, it is just clearer to me this time.

Explanation: I ferment low-alcohol beers in the serving keg - avoids all the intermediate steps including "priming" which would significantly increase the alcohol content. To ferment in a keg I have to use "spunding" valves to keep the pressure under control. For "spunding" valves I use secondary relieving regulators (not all regulators have relieving mechanism that are suitable for use as "spunding" valves - I use Shako NR200s) but they do need some static back-pressure to function. And this time I've not yet supplied that back-pressure or even fitted the "spunding" valve. What all that gobble-dee-gook means is I get to see clearly how tardy these low-alcohol beers are to start fermenting, plus, I've got 20L of fermenting beer in a sealed keg.

Eeek. Wonder if I'll get any sleep tonight before dealing with it in the morning?

Re: Mashing malted oats

PostPosted: Tue Jan 15, 2019 22:29
by PeeBee
No explosions! Well the keg has a PRV - I remembered that prior to sleeping. Spunding valve now fitted:

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The Sodastream bottle provides the back-pressure, nothing else; looks as if it really is being used as a regulator, but it's not. You can see fermentation is under way because the gauge on the regulator/spunding-valve is reading, and maintaining, 12PSI - as a regulator it's set to 7-8PSI, the 4-5PSI extra is the over-pressure needed to trigger the relieving mechanism. The two bottles (loose caps!) are because this style of keg holds exactly 19L and I brewed 20L (plus the keg is only holding 18L for some breathing space). The dry hop cages ain't in yet; they normally would be for the usual low-alcohol attempts.

Got a taster and it is surprising how alike to a full bodied beer it tastes at this stage. Whether that's the malted oats, the malted rye or the 73-4C mash temperature I can't say … probably all three. Starting gravity 1.026, currently 1.019, a lot stronger than my usual sub-1.010 "low alcohol" beers but this is an experiment and the best techniques will be scaled down for future.

I brewed 23L of 1.061 beer today; I'm not a saint!

Re: Mashing malted oats

PostPosted: Thu Jan 17, 2019 15:30
by PeeBee
Couple of days later and fermentation seems to have levelled off at 1.016. Dry hops been in a day but no impact on samples yet. 1.016 is very high but this is good as it indicates that when scaled down to 0.5% ABV the increase in body the rye/oats give will still have an impact. The low fermentability also allows more grain to be added (flavour) without exceeding 0.5% ABV. Picture shows little change over previous, but does show the "spunding" valve is holding things steady. Also shows tap connected for SG readings and sneaky samples.
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I probably need to move all this babbling to its own thread instead of hijacking this thread..