Will Oats ferment into alcohol?

I thought oats (flaked, rolled, steeped, toasted, or otherwise) were non-fermentable when used in a cider, but it appears that my champagne yeast is eating them up. It's been almost 2 months.

Is it possible that my apple wine is getting a boosted ABV from the oats?

Ingredients so far:

5¼ gal pasteurized apple juice
6 x 12 oz cans apple juice concentrate
1¾ lb rolled oats, boiled 35 min in 1 gal of the apple juice
½ lb toasted flaked oats, baked 20 min @ 300˚
3 lbs light brown sugar
1 c dark brown sugar
≈4 lbs granulated sugar
Lalvin EC-1118 Champagne Yeast

OG 1.110 (≈14% potential ABV). Current SG 0.999. Vinometer reading: 20-25% ABV, and tastes like it might be not far off. (The oats have been moving all over the place, like drifting sand dunes.)

Intended outcome: Maple & Brown Sugar Oatmeal Applewine 15-18%.

oats need to have their starches converted to sugar before they will lend any fermentables. I don't know what's going on in your cider, but the oats are not fermenting directly.

I see. Is it possible that any part of the oats somehow got converted to maltose or some other fermentable by enzymes, or molds, or some other thing?

From your ingredients list, the 5.75 gallons of AJ, 7+lbs of sugar and 6 cans of concentrate would give you an OG of 1.110 easily.

Not sure what kind of rolled oats you used, but it doesn't sound like you did a full mash on them and they probably don't have the enzymes to convert starch to sugar.

14% sounds right, I'm pretty sure the vinometer reading is off.

pimento said:

14% sounds right, I'm pretty sure the vinometer reading is off.

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I hope so.

I'm now contemplating whether I should rack off of the oats ASAP, or let it go as an experiment. The airlock has been bubbling around 8 seconds per bubble since I stirred it 24 hrs ago to hopefully settle the oatmeal stalagmites. Before then there was very little airlock activity, yet the SG has remained the same at 0.999. If it continues to bubble steadily yet stay at 0.999, should I let it go and see what happens? (Perhaps is it possible to have sugars fermenting that don't show up on the hydrometer reading?)

Seven pounds of sugar will take quite some time to ferment out completely. My last batch of cider had five pounds of fermentables and champagne yeast and it took a month to quit fermenting. I've had it in the secondary for a couple of months and plan on kegging it in September.

Thanx for the reassurance. I'm guessing that boiling the oats in apple juice caused them to soak up sugars, hide those sugars from hydrometer readings, and take longer to ferment. (Hence all the CO2 activity and no SG changes; and oat movement.)

Will the oats give a better mouthfeel if they haven't been converted by amylase? I understand they have that effect in beer, but will it work in cider??

As I understand it, if the oats are gelatinized they'll contribute to mouth feel. If they haven't been rolled or flaked (or cooked and/or pressurized into rupturing, i.e. gelatinized) it's necessary to steep (or boil) them to draw out the creaminess. And mashing will bring out even more mouthfeel, as well as create fermentables. Hopefully someone will correct me if I'm wrong.

I'm still very green, but my experience has been that gelatinized oats impart mouthfeel immediately to the brew, and bitter/tannin/astringency over time if left in (like a few weeks or more). Toasted oats will impart an oaty/nutty flavor, sort of oatmeal cookie-ish (and some bitterness if not allowed to rest for several days first - like in a paper bag).

My friend and I steeped 3 lbs of rolled oats (from grocery store bulk food section) for 55 min in apple juice and water, and poured only the liquid into his apple wine. This added noticeable mouthfeel, but we threw out a lot of good oatmeal. Local HBS owner later told me we could more efficiently use 1 lb pre-gelatinized oats, steep or boil for 5 min to pasteurize, and add the liquid & oats to the primary for a week, then rack off to avoid bitter flavors.

There seems to be some speculation that boiling the oats creates more bitterness than steeping them (not sure what that temperature threshold is though). Personally, I enjoy a touch of bitter notes.

I am going to make some oat-tea when I back-sweeten my apple brew, because lack of mouthfeel is one of my biggest complaints with fermenting apples. Thanks for the info and personal anecdote!!

I'd expect it to drop 3-4 more points, but very slowly. Probably a good time to rack it.

I agree.

So I racked it to secondary, added AJ concentrate, sugar, and apple juice to top it off. This took my potential ABV up to just under 18%. I plan to add maple syrup until the yeasts are pickled, leave it slightly sweet, and let it sit for a loooong time.

Observations after tasting it tonight: Very bitter and alcoholy, needs lots of time to mellow, could become very good - already full and complex. (SG 1.005)

I'm really impressed with the thick body, creamy mouthfeel, and complex flavor profile that's happening with my oatmeal experiments.

Good luck Justibone & others who are exploring this area too!

DrJerm said:

Good luck Justibone & others who are exploring this area too!

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I decided to do oats on the next batch, I just used glycerin to help this batch out a bit.

I fermented my 3 gallons cider for 2 weeks, then yesterday I added 1 pound of rolled oats that was boiled in water for ~5 minutes. It seems to have picked fermentation back up. Has this affected the OG of the cider? How can I tell how much its changed? The oats had 0 grams of sugar in them..

octo said:

I fermented my 3 gallons cider for 2 weeks, then yesterday I added 1 pound of rolled oats that was boiled in water for ~5 minutes. It seems to have picked fermentation back up. Has this affected the OG of the cider? How can I tell how much its changed? The oats had 0 grams of sugar in them..

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Only your hydrometer knows if the OG picked back up. Maybe your yeast were tuckered out because of some other limiting factor, like nitrogen or something, and perhaps the oats are providing that. Maybe it didn't ferment to dryness (did you taste it?) but adding the oats gave the yeast a stimulus, almost as if they were, as it were, "feeling their oats".

I know, it's a terrible, terrible thing to say.

I should be embarassed at my so-called sense of humor.

Without a sugar measurement before and after, there's not really any good way to guess whether or not the yeast are making more alcohol... but if they are fermenting more sugar it's not sugar they got from the oats, I'd wager.

Justibone said:

Without a sugar measurement before and after, there's not really any good way to guess whether or not the yeast are making more alcohol... but if they are fermenting more sugar it's not sugar they got from the oats, I'd wager.

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alright, thanks. It probably just stirred up some yeast. How long should the oats stay in to add to mouth feel? would ~ 2 days be adequate?

2 days might be perfect. I'd taste it each day and see.

Probably no more than a week though, unless you want it to develop bitter flavors.

Oats have a lot of nutrients and complex starches that fermentative bacteria like. When left at room temperature for several days, the oat liquid naturally ferments. It turns into a refreshing beverage full of probiotics and easily digestible nutrients, both from oats and bacterial metabolism. I did a lot of research about oat fermentation and health benefits in this post, if you’d like to check out more science. These days folks add a touch of sugar and raisins. The oldest versions use only water and oats, and sometime dried fruit or berries. Either version is fine since there is none, or very little, residual sugar remaining after fermentation. You can add a touch of honey, although it does change the flavor and almost dominates it. Simple oat kvass is very mild and pleasantly oaty. It can be slightly tangy, or quite tart if left to sour for a longer period. It does develop traces of alcohol, but insignificant enough quantity to mention. I don’t have any official data about it, but folks in Russia say it’s about the same amount of alcohol as in kombucha. http://www.beetsandbones.com/russian-fermented-oat-kvass/