Stuck or just slow?

[kevinb]

I have my first mead in my primary fermenter. It is plain mead, just Honey from my LHBS. I used about 10.5# of honey and enough water to get to about 3.25 gallons. I oxygenated it with pure oxygen, did staggered nutrient additions (Fermtek) and stirred to degas for the first few days. I used one packet Lalvin 71-b that I rehydrated. I have it fermenting at about 64°F. My starting gravity two weeks ago was 1.118. I just took another gravity ready and I am at 1.037. Based on this yeasts alcohol tolerance I expect this mead to ferment down to about 1.012 based on a 14% alcohol tolerance. It looks like the fermentation is very slow or might have even stopped. Finally my question, do you think I have a stuck fermentation or do I just need to give it more time. I am used to beer that ferments relatively quick so I am not sure how long this takes to finish. Second question, when do I rack to the secondary to start clearing?

 

[Complete_Amateur]

That sounds like a lot of honey for 3.25 gallons. I think your starting gravity was higher than you thought. Honey is difficult to dissolve in water, especially as the concentration of honey increases. If your honey was not completely dissolved when you took your reading, your reading will turn out low. If that is the case, you could already have reached terminal gravity for your yeast strain.

There are also calculations for determining what your gravity "should" be based on the amount of sugars you are adding, but honey is not 100% consistent (varying moisture content). I have read that it contributes 42 Gravity Points per pound. If this is true, your starting gravity was closer to 1.136. With your current gravity, that gives you 13% alcohol, approaching terminal for 71-B.

Check again in a few days, and if it hasn't progressed it could be stalled. You could pitch a more alcohol tolerant yeast that is reliable for restarting stuck fermentations (EC 1118 - which also has a significantly higher alcohol tolerance). You could also have a sweet mead.

 

[kevinb]

Thanks for the great explanation. Can you explain what you mean by gravity points to determine the 1.136?

Looks like a trip to my LHBS this afternoon. I don't mind a little sweet, but 1.037 seems a little too sweet.

 

[Complete_Amateur]

Thanks for the great explanation. Can you explain what you mean by gravity points to determine the 1.136?

Looks like a trip to my LHBS this afternoon. I don't mind a little sweet, but 1.037 seems a little too sweet.

There is a great explanation of it here somewhere, but a Gravity Point is the contribution to the total gravity of the must/wort of a sugar. It is measured in points per pound per gallon. To calculate the expected gravity, you multiply the points of your sugar by the pounds used, and divide by the volume of your must:

42 points * 10.5 lbs / 3.25 gallons = 441/3.25 = 135.9 total gravity points

(Gravity Points / 1000) + 1 = Expected Gravity (original)

~ 1.136

 

[kevinb]

When I re-pitch do I need to use any more nutrient or energizer?

 

[Complete_Amateur]

When I re-pitch do I need to use any more nutrient or energizer?

At this point in the fermentation I would hesitate to make any non-flavor additions (but then I lean on the side of adding less stuff in the first place). What you might want to look into is making a starter for the new yeast, and adding some of your must to acclimate it before pitching.

Others may have more helpful info on adding nutrients at this point, but I would wait a few days, taking readings every day. If it goes several days without dropping, you can conclude it has stalled, and decide what to do from there.

 

[kevinb]

Thanks that is what I am going to try. Just left my LHBS and they suggested the same thing.