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View Full Version : Fermentation appears to be slow/stuck at 1.065



jamisonia
10-20-2014, 09:59 PM
Making a 1 gallon batch of Mead on 9/21/2014

3.5 lbs Honey
1 package 71B-1122
1/2 tsp Wyeast Nutrient Day 1
1/4 tsp wyeast nutrient day 2
1/4 tsp wyeast nutrient day 4
OG 1.121

I oxygenated with pure O2, dissolved with an aeration stone. Initial fermentation was vigorous. Subsided after a week.

10/7 the gravity was 1.068. 10/14 it was the same. I then added 1/4 tsp of Potassium Bicarbonate, and a 1/2 tsp of yeast energizer.

Checked the gravity today (10/20), it was 1.065.

This seems painfully slow. From reading it seems I made a mistake not Oxygenating it more after initially pitching the yeast. But have I already passed too far where I may encounter oxidation issues if I oxygenate some more? Also it seems I should have added the yeast energizer and potassium bicarbonate earlier, but I hadn't read about these things originally. If you can't tell I come from homebrewing, so I honestly though oxygenating with pure o2, and pitching a ton of yeast would carry me through.

Thanks in advance.

Chevette Girl
10-20-2014, 10:54 PM
I suspect another little blast of O2 wouldn't hurt it at this point, but if it's still moving, it's still fermenting. And you don't want to add energizer at this point, that should be added at the very beginning of the fermentation when the yeast is increasing its colony size.

Beer, huh? I came from a winemaking background, there are differences both ways :)

First, adding 3.5 lb honey and using 71B as your yeast, I don't expect this to go dry. I'm too lazy to run the numbers throug the mead calculator for you but I'm guessing that's at least 18% potential alcohol and if I recall correctly 71B usually taps out around 14%.

Second, because you're using so much more fermentable than when making beer, and you're generally working so much closer to the yeast's alcohol tolerance that it's tough for the yeast the closer you get to the end of a ferment, so it's pretty common for the SG drop rate to drop off.

Third, you know with your beer that yeast makes acidity... well, more fermentables means more acid, and it's possible that the pH is too low for the yeast, it's a common problem with traditional meads. Additionally, honey contains its own kind of acid as well, which you don't see with beers, and doesn't have any kind of buffering ability like fruit does and I imagine grain might. If you can check the pH with strips or a meter, you'll want to add more potassium bicarb if it's below about 3.8.

If you're going to start with a high initial gravity (I consider anything over 1.115 to be on the high side, your mileage may vary) you might want to make an acclimated starter when you pitch your yeast, it gets them used to the high sugar content as well as giving it a headstart on colony growth.

If you're convinced that the 71B has given up and you want the SG down more (wouldn't blame you, 1.065 is pretty syrupy to drink), you may need to make an acclimated starter with some EC-1118, it's good for restarts and has a tolerance of 16-18%, just be warned, it's kind of a beast once it gets going and may well take your batch dry.


Oh, and where are my manners?? Welcome to Gotmead (and the meadmaking addiction the rest of us seem to suffer from)!!!

jamisonia
10-21-2014, 12:33 PM
Thank you.

I chose 71B on purpose to crap out at 14% so it ends around 1.015. I wanted the Mead to be Semi-Sweet, as I made Mead one time before using Red Star Champagne yeast, and that stuff was way too dry for my liking. I know I could backsweeten, but I was hoping to maybe avoid that by choosing the yeast appropriately. Also 14% alcohol seems about right for me.

I was thinking I should dissolve more O2. will do and report back.

Pepe
10-21-2014, 01:17 PM
Welcome! I don't happen to see what temperature you are fermenting at? That could play a role if it has gotten sluggish.

jamisonia
10-21-2014, 04:42 PM
Originally at least 70 degrees. i didn't keep tight control over it, but I know the area was around 70. It had cooled down significantly around me, so I moved it upstairs, my house is now only about 65, but I'm not ready to turn the heat on yet!

Spatik
10-24-2014, 10:44 AM
You are still ok. Add 2 g of DAP and 2 g of nutrients ( I use ferm k). Stir it and get all on that co2 released. Keep that process up until half of your sugar is fermented. As far as temp. I try to keep it at 64 to 68. Anything above 70 and I think you start getting off alcohols.

Medsen Fey
10-26-2014, 01:04 PM
At this point DAP is not going to help. You are half done and the yeast won't be able to assimilate DAP, and it may drop the pH lower. Check the pH. If it is below 3.3, raise it to 3.5. Add yeast hulls or boiled bread yeast 1-2 g/gal. Aerate it again. If that doesn't work, you'll need to pitch a different yeast.