Stuck fermentation?

[kbreezy]

Hey, all - new here. Great resource site you have going.

I have a fermentation question: I recently made a batch of Ben and Becky Starr's Starrlight Mulled Apple Cyser. The recipe calls for Lalvin Narbonne yeast, and I rehydrated it and pitched it without making a starter. The fermentation stopped at 1.032 and does not appear to want to go any further. I made a starter with an additional two packets of the Narbonne yeast and pitched it a month after the first pitching, but there was no change in gravity at all - still stuck at 1.032.

To me the mead tastes a bit thick on the tongue, even for a sweet mead - like it could stand to lose another 10 points at least, and the recipe specifies a FG of 1.014. Could someone suggest a way to jumpstart the fermentation another 10-18 points? I was thinking about adding a champagne yeast but then I'd have to use bisulfate to stop it before it dried out too far, and I've been thinking of bottle carbonating it. The bisulfate would prevent that, but it's not essential that I carbonate it, I guess.

Suggestions to a) jumpstart fermentation or b) thin the mead a touch? Any help would be appreciated. Thanks!

Kbreezy

 

[wildaho]

Hi kbreezy and welcome to the mean green (but friendly) GotMead? Machine!

Can you give us more details on your recipe and process so far in a list format? Please include all ingredients, volumes, temperatures, gravities at various points, yeast strains, re-hydration methods, nutrient types and additions, times, etc.

Without these we are shooting in the dark. This is not a recipe I'm familiar with although I do a lot of cysers. If you can list your recipe and your procedure and results, we're more likely to able to pin point how to help.

:cheers:
Wade

 

[kbreezy]

Sure. here's the recipe:

Ben and Becky Starr's Starrlight Mulled Apple Cyser
O.G. = ~1.120
F.G. = 1.014

Ingredients:
16 lbs Wildflower Honey
5 gal Apple Cider – no preservatives, sulfites
4 Tbsp Cinnamon, ground
1 Tbsp Clove, ground
2 Tbsp Allspice, ground
2 Tbsp Nutmeg, ground
2 Tbsp Orange peel, dried
6 seeds Anise (optional)
1 tsp Yeast Nutrient (DAP – diammonium phosphate)
Potassium Sorbate (optional)
10 g (2 packages) Lalvin Narbonne Yeast (71B-1122)

I warmed the honey in about a gallon of the cider and added the spices, and then poured it into the carboy on top of the rest of the cider. I rehydrated the yeast and pitched it, and added the nutrient to the carboy a couple days later. OG was 1.128 and the fermentation temperature fluctuated between 68-72 degrees Fahrenheit (my temp control is poor).

I checked the gravity a couple times over the next few weeks, and noted that fermentation appeared to have stopped entirely (at 1.032). At six weeks, I made a starter with a couple more packets of the 71B and some light dry malt extract I had on hand, and a day later I decanted the spent wort and pitched the slurry back into the mead for another try. There was no apparent activity after a couple days, and I measured again this week and found it still at 1.032.

If there's an efficient way to ferment this another 10-18 points I'd be in favor of that, but it does taste very good (though a bit thick), so if thinning it with a bit more unfermented cider or water is another option I might consider that. Any other suggestions? And thanks for the quick reply.

 

[Teufelhund]

You could try Uvaferm 43 @ 8 g. The 71-B is rated for 58*-85* so your temp fluctuations shouldn't be the factor.
Try racking and add the Uvaferm & see what happens.

Cheers!

DD

 

[wayneb]

You should also take great care to rehydrate your re-start yeast according to the manufacturer's recommendations, using Go-Ferm if you can get your hands on some, and also acclimate the new yeast to their new alcoholic environment by adding small amounts of the stuck must to your rehydrated yeast several times over the course of a day or two before pitching that acclimated starter into the main must. With a fermentation that has progressed this far before sticking (you're already over 11% ABV), re-starting will be a challenge for any strain of yeast.

 

[Medsen Fey]

Hello kbreezy,

I'm curious - did you aerate this batch during fermentation?

It looks like you are at about 12.5% ABV and so restarting will not be easy. Adding more 71B will be an effort in futility. You can try using yeast that are known to be able to restart fermentation such as EC-1118, K1V, Uvaferm 43. With these yeast you will need a starter and to acclimate the yeast to your must.

Also, keep in mind these yeast will likely take this batch dry, so you will end with higher ABV, and will need to backsweeten to get to the gravity you were looking for. If you do manage to get it restarted, you will have a devil of a time trying to stop it with sulfites (You can sterile filter it, or you might be successful if you cold crash it first,) so plan on backsweetening.

There are also the Pro-restart encapsulated yeast that are already primed for the harsh conditions of a restart. They are kind of pricey, and will also take it dry, but may be easier than a starter for some folks. It is possible that pulling the yeast out will allow you to keep it sweet, but I haven't tested that yet.

Your best bet might be to keep this batch sweet, and make another batch completely dry then blend the two to get the sweetness just where you want it. If you rehydrate with GoFerm, the yeast are more likely to reach their alcohol tolerance.

Endeavor to persevere!
Medsen

 

[kbreezy]

Thank you all for the suggestions. I'm much more familiar with beer brewing than mead making so some of this info is brand new. If I can't get this restarted I may cut it with a bit more cider, or make another batch with champagne yeast and blend, but I have to give this a shot first.

I'd never heard of Go-Ferm because I use almost exclusively Wyeast smack packs in brewing. I'll definitely pick some up and try it on the repitch.

Acclimating the yeast to the alcohol level is something I wouldn't have thought of but seems obvious now that I know about it. Thanks for the tip. I don't see Uvaferm 43 available at my local suppliers but both the Lalvin yeasts are readily available so I'll probably try one of them.

A few specific questions:

1. I did not aerate during fermentation...why? This typically isn't done with beer - is it advisable with mead?
2. Sulfites don't necessarily stop the fermentation?
3. If I should find that the mead has gone too dry, what is a typical way to backsweeten?

 

[Medsen Fey]

1. I did not aerate during fermentation...why? This typically isn't done with beer - is it advisable with mead?

It is not only advisable, it is essential to reach maximal alcohol tolerance. For beer brewers this often seems to be total heresy but for wine and mead, the yeast need oxygen to form the most alcohol tolerant cell membranes possible. Check the link in This Threadfor more reading.

2. Sulfites don't necessarily stop the fermentation?

Sulfites (and Sorbate) are much better at keeping fermentation from restarting once it has stopped than they are at stopping an active fermentation. This is especially true of Champagne yeast which have been selected over time to be more SO2 tolerant than other strains.

3. If I should find that the mead has gone too dry, what is a typical way to backsweeten?

I let it completely clear, then I rack, and stabilize using sulfites and sorbate. Then I dissolve honey in water to make it easier to mix in somewhat like what Wayneb describes in This Thread. I add it gradually to get it to the right level of taste.

I hope that helps.

And by the way,

Welcome to the new and improved* GotMead!​

Medsen​

*With pink hearts, yellow moons, orange stars and green clovers... err, I mean green honeycombs! ;D​