Home Distiller

Top of the morninig (afternoon) to everyone,
I'm looking for an explanation and possible solution to whats going on with my current fermentation. So, I Followed an AG recipe very closely that is outlined on the parent site by Tarvus. I used 25 lbs wround white corn, 5 lbs ground wheat and 17 lbs malted 2 row. Everything went great with the cook and mashing session. I ended up with a SG of 1078 corrected from 1070 at 125F. Topped up with filtered rainwater to the 30 gal mark to acheive sg of 1050. Let cool overnight and pitched yeast (60g of distillers yeast) the next AM (Sunday) at 91 deg F.
Im fermenting in a 55 gal food grade drum with a blow off tube on top. By the end of the day it was bubbling solidly. Continued like that till Mon afternoon then I noticed the bulling had stopped. Opened the lid and there was a THICK cap and the Co2 about knocked me on my ass (which is fine). There is a slight funky smell mixed in with the normal smells. Kind of lactic and sour. Not overwhelming though. I checked the SG and it was at 1013. Put the top back on and observed no more bubbling action.
Am I stalled or is it done? If stalled how would yall reccommend kickstarting it, maybe yeast bomb? I believe the initial conversion went well so i dont think available sugar was an issue. Also is a slight funk smell normal for yall? This is my first AG ferment of this size.
I reeeeally appreciate any advice!

It's not done but almost. The acid is normal with an AG. The yeast doin their job release CO2 which acidifies the wash. The cap is also normal. The CO2 hooks onto the grains and make them float. With an AG they more often than not finish at an SG above 1.000. Wait until the cap falls, then have at it.

Big R

rtalbigr,
Thats reassuring man I was hoping it didnt get infected. It sure seems a little quick to be almost done though right? Pitched yeast Sunday morning and quit bubbling hard by Monday evening.....
I know the cap, Co2, acid etc. is normal but what about the funky lactic smell? Just slightly pukish. Not overwhelming though.

Well, first of all your OG of 1.050, while not unreasonable, is just a little low, I wouldn't have add so much water. Second, for a 30 gal ferment at that OG I would have added no more than 30 gm of yeast. So, a low OG and Lots of yeast, a fast ferment. Some here prefer a fast ferment but I don't, I prefer a more steady ferment for an AG.

Lactic souring is pretty common with AG's and not anything to worry about, per se. If the wash sours too quickly however, it can affect yeast health. Some yeast do well in low pH washes, some don't. Distiller's yeast doesn't do well if the pH drops below 4.8.

Note: if you plan on using the backset in a future mash make sure you check the pH.

Big R

That all makes good sense. I wouldn't have added so much water but that is what the recipe called for so I went ahead with it. I chose 60 grams of yeast because the recipe didn't specify a type or amount so I referred to the parent site (which is what alot of the veterans of this site would avise me to do). There it says 2-4 grams of dried yeast per gallon of mash. Maybe I shouldnt have included the ten gallons of water i added into the equation. I find that many recipes will be very precise on the cooking and mashing method the just say "pitch yeast" without specifying what kind or how much.
Anyhow, I'm going to run it all this weekend if I find the time. Thanks a ton for the help!