AGs stalling at 1.15...?

[Almtngoat]

Not really stalling but really slowing down, I hit this point after about 10 days and have to wait another 15 days for the cap to fall. I use DADY yeast and nutrient, and enzymes. This is happening with my last few batches. Granted my recipes are very grain heavy , 2.5# per gal., so my caps are huge and dense. My question is, should I bust that cap with my giant egg beater to give the yeasties more oxygen or just drain and run and let the piggy back take care of the rest?

[NormandieStill]

Is your OG 1.150? If that finished dry you'd have almost 20% abv in the wash.

Or are they reaching 1.015 and slowing down? What temperature are they at? You could check the pH although on-grain ferments usually buffer themselves (in my experience).

If it's the latter then I'd refer you to the numerous lines here about patience. Put your ear to the fermenter and listen if it's still active. Even if it's quiet, you can just leave it alone to clear. The longer you can leave the yeasties to do their thing, the cleaner the final result will be. Patience in this hobby starts with the ferment, not just the time on oak. If you wait another 2 weeks before distilling then you'll have to wait another 2 weeks on top of the year or more of aging. At that point it's peanuts.

[Almtngoat]

I put my giant egg beater in there and gave it a good stir and the yeasties burped happily... My meter read at 4% still in the mash.

[NormandieStill]

I put my giant egg beater in there and gave it a good stir and the yeasties burped happily... My meter read at 4% still in the mash.

The highlighted bit in your post makes me wonder if you know how to read a hydrometer correctly.

If you want to go by the numbers and you haven't run the identical recipe hundreds of times to have a feel for the possible variance, then you need to take a reading every couple of days. If the readings differ, it's still going. If you get the exact same reading at least twice, two days apart, then your wash has probably reached the end of it's fermentation. The "potential alcohol" value on your hydrometer is just that, "potential". Whether you get that depends on the proportion of fermentable sugars, the alcohol (and temperature) tolerance of the yeast, and the available nutrients.

Have patience young padowan. Yeast have been doing their thing quite successfully since long before your ancestors discovered that cooked food made fewer people die, and without any intervention on our part. Resist the temptation to intervene. Unless you know exactly what you are doing, you risk making things worse rather than better.

[Homebrewer11777]

I'm pretty sure issue here is that gravity reading. Was this taken with a hydrometer or refractometer?

If refractometer did OP use calculator that corrected for presence of alcohol in the mash? This is really common issue in the homebrewing forum for new brewers with concerns about their "stuck" fermentations. A proper calculator for converting a refractometer reading of a fermenting wash will require you to input original gravity and current reading (usually in brix) to calculate the gravity.

The NB calcuator linked in this board's wiki is free and located here: https://www.northernbrewer.com/pages/re ... calculator
It is kind of a pain to use because it wants you to know the brix of your mash pre fermentation and most hobby brewers (either for beer or distilling) think in terms of gravity. Brewer's Friend has a free and IMO better calculator here: https://www.brewersfriend.com/refractometer-calculator/ a bit overcomplicated with the wort correction factor but just leave it at 1 and you will be ok...

For unfermented wort a reading of 4 brix indicates SG of 1.016
For fermenting wort that had an OG of 1.072 a reading of 4 brix indicates SG of 0.984

[still_stirrin]

This comment makes me wonder if the Alabama Mountain Goat really understands how the yeast work:

… should I bust that cap with my giant egg beater to give the yeasties more oxygen…

If the yeast has fermented down to a SG=1.015, then it is likely near flocculation as the process completes final consumption of the sugars. But, oxygen is NOT needed for the yeast to work because during the process of fermentation, the yeast consumes sugars and produces the oxygen needed for respiration. Agitation by stirring “with the eggbeater” only caused CO2 to break out of suspension in the beer, creating the “burping in the bubbler” noted. And when you stir the beer, producing the “gush” of bubbles, there is usually a period of no bubbling as the slow activity tries to replenish the dissolved CO2 into suspension.

The bottomline is that 1) the beer is almost done, and 2) this last part of fermentation is the slowest, often taking longer than the fermentation has taken to get to this point. As an example, this chart shows the relative lifecycle of yeast during fermentation:

Yeast Lifecycle

Notice how the activity asymptotes as it approaches the end, or termination of fermentation. You simply need to wait on it to finish.
ss

[The Baker]

Almtngoat wrote, 'My question is, should I bust that cap with my giant egg beater to give the yeasties more oxygen or just drain and run and let the piggy back take care of the rest?'.

Winemakers using open tanks press the cap down so it doesn't dry out.
You should probably do the same.
Just press it down, do not use an eggbeater!
Oxygen is not needed.

Geoff