Funky post-fermentation beer-like smell

[Stressbaby]

A few of my wines have finished and cleared with a funky smell. I first noticed this with persimmon. I had trouble identifying the smell, it was clearly not a yeasty "bread-like" smell but it was not pleasant and definitely not "wine-like." It persisted for months, despite degassing and completely clearing the wine, and seemed to gradually improve and nearly go away. I concluded that it was unique to persimmon, bottled my wine, hoping the persimmon wine might "do the dandelion," and emerge as a wonderful wine in a year.

Two things happened yesterday to make me post today. Wood1954 posted here about an apple wine he made that smelled like beer for a year. I said, "Beer! That's it! That funky smell is just like beer!" My wife confirmed. The second thing was that after I backsweetened my Valencia orange wine, I identified that same smell in the orange. The taste is great, the wine is clear, but it has that smell.

Two questions:
1. How do I prevent this? One thought I had was to try lower fermentation temps. I thought I was starting to get this in a batch of loquat last week. I cooled it from 78F to ~68-70F and it seemed to resolve, but I don't know.
2. Will this resolve in the bottle or do I need to keep these wines in carboys, racking periodically, until it resolves?

I appreciate any and all replies.

Robert

 

[Turock]

Are you using nutrient? HOW are you using it? If you're using it, do you pitch it all at once?

Fruit wines and whites should be fermented at cooler temps---down around 70-72 degrees. But a fermentation should not have "off" odors. A lot of this can be due to improper nutrient. Also what cultures are you using? Some cultures need the more complex nutrients like Go-Ferm.

 

[Stressbaby]

I have been using generic yeast nutrient at around 1t/gallon. I have been adding it at the beginning, usually prior to pitching the yeast, sort of based on standard Keller recipes and variations thereof. I also wondered about the nutrient issue, and so I've purchased Go-ferm and Fermaid-K in preparation for my next batch of persimmon (which I haven't started yet).

I have done the persimmon with both D47 and Red Star Pasteur Champagne, and is seemed to occur with either. I have made 3 batches of persimmon with D47, some more remarkable for the smell than others. The orange was also with D47. But it can't be solely the yeast. I've made what I think are some really good wines with D47, no smell whatsoever.

Any suggestions as to a remedy? Think it will improve in the bottle?

 

[Stressbaby]

One more thing, I don't know if this helps or not...with the persimmon, the smell developed during fermentation. With the orange, it seemed to develop later. I didn't notice the smell at all when racking it previously, just this time. Crazy...

 

[Stressbaby]

In an effort to answer my own question, I opened one of the bottles of persimmon. This was started just over 9 months ago and bottled in May.

The smell is completely gone. The wine is decent, drinkable...over-oaked maybe, but entire absent of "le funk."

 

[Arne]

This is just my own opinion. I have had the same thing happen and have had it go away with time. I think it is from the yeasts being stressed and it comes from them giving it off during ferment. If you hold your breath before and while tasting, it tastes ok, but leaves a bit of an aftertaste. Once it sits long enough the oder goes away and the wine is fine. I have been step adding the nutrients lately, and since then have not experienced the problem. Arne.

 

[Stressbaby]

Thanks. The consensus seems to be that it is nutrient related. Is there any benefit to Go-Ferm + Fermaid over step additions of plain yeast nutrient?

 

[Turock]

That's why I asked you how you're using nutrient. When the yeast doesn't have enough nutrient support thruout the fermentation, it gets stressed like Arne said and produces off odors.

To avoid this problem in the future, get used to dividing the nutrient into 3 batches. This keeps the yeast fed as they produce new generations so that everyone is fed properly. Your fermentations should have nice aromas.

As I said, some yeast, like 71B, need the more complex nutrients. Scott Labs always recommends Go Ferm with 71B. But if you're using D47, Pasteur,etc. you should be fine with standard nutrient. Your whole problem seems to center around not dividing the nutrient. Start doing that on your next fermentation and you'll see the difference.

 

[Stressbaby]

Will, thanks as always, Turock.

 

[salcoco]

some standard nutrients actually stress the yeast if added at the beginning of fermentation but okay after fermentation starts. conventional protocol is using go ferm to hydrate yeast then add fermaid k after 1st day of fermentation start. second batch of fermaid k added at 1/3 depletion of sugar. I use a refractometer to monitor fermentation and use the conversion calculation on Valley Vitners site for conversion to true brix and sg. calculation takes in affect of alcohol in refractometer reading.

 

[Stressbaby]

Update:
I have 6 gallons of persimmon. I changed the following:
Go-Ferm with yeast hydration
K1-V116
Fermaid-K at 1/4 SG drop
Rotating ice packs around the bucket to keep the temp down <22C.
Bentonite day 3.
Stepped sugar additions

It is a nice, slow, even fermentation; hardly any foam, and no smell whatsoever.

I found my persimmon formula! THANK YOU!