Help with wine taste and fermentation!

[Landwaster]

So I made some wine from Chilean Malbec juice with my cousins for the first time on our own last spring. The fermentation didn't quite finish (4 5-gallon carboys around 1.008 - 1.010). The wines taste slightly sweet. We'll probably throw in some yeast to try to finish them up.

This past fall we were late to the game and got a variety of Italian juices that were already naturally fermenting (Merlot, Sangiovese, Lambrusco). So we pitched in Lalvin RC212 and let them go. We tasted them recently after 3-4 months aging in the carboys and they also seem slightly sweet like the last batch (to varying degrees). Now, the carboys were split between me and my cousin. The carboys my cousin has are at 1.000 - 1.008, the temperature in his cellar is a chilly 55 though I believe he had a space heater running during fermentation. The carboys I have at my house were upstairs at 58-68F for about 4-weeks as they fermented and as I added ML bacteria. According to my notes from when I racked them, they were down to .996 and .998. The other day I tasted one of these carboys and it also seemed slightly sweet!

So now I'm really confused because all these different batches seem to be coming out with the same sort of sweet taste. For the first batch from last spring, I thought it was because they weren't fermenting to complete dryness, but that theory seems to be out the window since my own recent batch tastes similar. Am I just uneducated as to what young wines taste like? Or is there something else afoot?

 

[kevinlfifer]

I am experiencing the same thing with a Red Zin juice bucket. Its been fermenting since 12/20 FINALLY down to .998 and is a bit sweet. I'll wait til .992 even if it takes til June. My ambient temp is 74-76 F and it is still that slow.

 

[dangerdave]

"Landwaster"? Your first name wouldn't be Kevin, would it?

As for your story/question, I'm affraid you've got me on this one. A year fermenting? Have you check the calibration of your hydrometer?

Young wines (particularly reds) are most usually rather tart.

 

[Turock]

Well, I'm suspecting that your nutrient feeding schedule wasn't quite right. When you have a low YAN must, you can either get H2S problems or the ferment becomes stuck. What kind of nutrient did you use and what kind of schedule did you use when pitching the nutrient?

Don't throw in more yeast. The best protocol is to add yeast hulls because they will absorb the toxins that are keeping the yeast from finishing. You sure don't want any nutrient in the ferment NOW---especially the one under MLF!! You can find yeast hulls just about anywhere, or at www.morewine.com

 

[Landwaster]

Lots of questions, thanks for the advice:

Could you explain what YAN is an acronym for and what I should know about it? I added super ferment (whatever the recommended amount was on the bottle) when I pitched the yeast. Never added nutrient after that. What do you recommend adding as the fermentation goes along?

So you would throw in hulls for both batches, the year old and the 3 month old? Both batches were racked once, would that make a difference as to whether there is enough yeast left over to finish up the fermentation? Should I bring them upstairs to a warmer temp and stir them a bit to get some air in there for the yeast?

For a dry red should my goal be .990? My cousin was in charge of the year-old batch and didn't take the OG measurements, and the 3-month batch was already half-way fermented so I don't know what they started out at.

 

[sour_grapes]

YAN stands for "yeast-assimilable nitrogen." Lots more good information available here:
http://www.winemakingtalk.com/forum/f86/yeast-nutrients-39655/

 

[JohnT]

Seems to me that you might have cooled your wine down too much and too soon. Try bringing the wine up to about 75 degrees for a couple of weeks. This may kick off the fermentation again (unless you have added sorbate or finish levels of k-meta).

 

[Turock]

It's always wise to step feed nutrient instead of throwing all of it in at the beginning.

Super ferment is DAP and yeast nutrient. One large initial dose of DAP can delay or inhibit the uptake of amino acids by the yeast cells--adding nutrient like Fermaid K all at once leads to a fast ferment and an imbalance of uptake and useage of nitrogen compounds. You should always step feed nutrient so that you have a smooth ferment and the yeast has what it needs to go to completion. I'm sure this is what happened and why all the wines finished sweet. Ferments that are low on nitrogen can end up not going to dry. You always want your ferments to go to the dry stage.

Yeast hulls are safe even for the wine under MLF. Yes, MAYBE some warmer temp would help in some situations. In the 1 year old wine, I presume you have racked that down to where you have the bulk of the yeast cells racked off. I'm not sure if the hulls would help there. It would require some study, as I'm not familiar with using them so far from the ferment. But it should certainly help the 3 month old wine---once the hulls are used, the yeast might be able to finish off the fermnet and go to dry.

Study up on step feeding nutrient---it's the only way to run your ferments so that you don't get into these issues.

 

[Landwaster]

Thanks for the advice. I'll go ahead and give the yeast hulls a try. What's the time frame for that? Should I give them a few days, a few weeks, and check the gravity?

I had read up about the whole process before going out on my own, but never got the impression that step feeding was important. Of course, there's always a big difference between reading something and actually doing it.

 

[Turock]

I want you to go read this for yourself because the restart protocol depends on the brix your wine is stuck at. You'll get a big education on restarting a stuck ferment and about how important the nitrogen levels in you wine are, which is directly related to nutrient management. Go to www.lallemand.com and search for stuck ferment.

The yeast hulls will clean up the ferment so your restart will be successful. All the info you need is on that site.

 

[Landwaster]

That document is a ton of help, thanks. I'm going to try it this weekend. I'll use yeast hulls first and see if there's any action, and if not, then go ahead and do their procedures for reintroducing yeast. Here's a more direct link if anyone else is interested: http://www.lallemandwine.us/laboratory/stuck.php

 

[Turock]

I'm glad that you went and read that! Sometimes when I give people info like that, it seems so complicated to them that they just don't bother. I'm glad you're willing to take this on. You'll learn alot from this--and also how to prevent it in the future. I'm pretty sure you'll have to restart the ferm. Let me know how this works out in the end.