how "stuck" is stuck?

Five weeks for a red fermentation? You didn't say what strain of yeast you used, but it's certainly not very vigorous! Normal would be about a week to ten days. Could be you hit it pretty hard with SO2.

Anyway, if it's still bubbling it isn't stuck. How does it taste? Is it still sweet? BTW, what's the pH and how much sulfite did you use?

Tom S

I used RC212. Initially, it was in a relatively cold basement (about 68 degrees). For the last few weeks, it's been in a much warmer area...now up to about 80 degrees. The pH is perfect at 3.40. Yes, it tastes VERY sweet now, so although I'm never confident of my ML chromatograms, I'm sure it's still got a fair amount of sugar. To look at the neck of the carboy, it's got too numerous to count constant tiny bubbles. I plan to run a repeat ML test tonight, but the SG just doesn't seem to be budging much. I have some whites currently fermenting with a premier cuvee yeast, so I have a ready supply of actively fermenting yeast...plus I could always add new powdered yeast.

Tom, let me ask you another question: After you go through a primary on reds, and then you press, and then you have maybe 2 inches of sediment on the bottom of the carboy, how quickly do you rack to get rid of the sediment? I plan to run an MLF on this new batch of a combination of syrah, mourvedre, and grenache, but I'm concerned that without sulfite I'll get too much H2S. How soon would you rack?

Lee

Within a day. You want to get the main bulk off the gross lees ASAP. You can resettle that later and combine it into the good stuff if it doesn't develop the stinkies.

If you have an active, alcohol acclimated culture of Prise de Mousse (EC1118) going, I'd give that sweet Syrah a racking to give it some air and add that to it. If that doesn't ferment it out, nothing will.

Tom S

So, what's your preferred procedure for getting some fresh yeast ready and willing to dive into a nearly fermented wine and pick up the job where the old yeast left off?

What are your thoughts on still having a lot of the old yeast in suspension? Could these actually work against the new yeast by increasing flocculation and taking them out of the game? Would it be better to let the stuck wine clear out for awhile, then introduce some new yeast?

Brian

I doubt that clearing the wine would help any. My experience with stuck fermentations has been problematic at best. When a wine stops off dry like that, it's very hard to get it back on track without a substantial addition of fresh juice, and any delay gives spoilage organisms an opening.

Still, it is possible that the combination of low temperatures and high free SO2 basically suffocated the yeast, and a shot of air and an active culture could perk it right up again. The starting Brix wasn't all that terribly high.

FWIW I'd say it was a mistake to sulfite the must prior to fermentation. There's no reason to do that unless the fruit looks pretty funky to begin with. I realize that he was trying to inhibit ML, but I really don't see the point in that if he intended to put the wine through ML after blending anyway.

Tom S

That's a debatable issue Tom, and many would disagree with you! SO2 is often added to prevent polyphenol oxidase (PPO) enzymatic oxidation of the must (not just to stun native yeast and bacteria).

The premise behind the "brown juice club" is that the phenols oxidised by PPO enzymes are the same as those which will later be oxidised and browned in the wine. This may not be the case and, infact, many flavonoides are not oxidised fully through PPO activity.

Ben Improved Winemaking

When I read over my initial message, I realize that I wrote something inaccurate. My primary fermentation of this syrah proceeded well for about 10 days, with the SG dropping to about 1.010. I had sulfited to about 50 ppm before adding any yeast. While not completely dry, my schedule for the next few days was hectic, and I figured that I'd press at that point, and allow the primary to go to completion in carboys off of the skins. It was at that point, after pressing, that the SG stopped dropping. While I still see consistent tiny bubbles, the SG is dropping VERY slowly. After seeing no change for about

2-3 weeks, I moved it to a warmer area, stirred vigorously, added nutrient, added a little bit (probably too little) of a sweeter actively fermenting must, and now, about a week later, I'm still at about 1.002...not a heck of a lot of drop over a week with all of these bubbles.

I think I'll run another ML chrom and see whether the bubbles are actually an MLF, and at the same time add a brand new batch of a yeast.

With what should be only a small amount of residual sugar, this wine tastes extraordinarily sweet and fruity. The fruitiness I like...the sweetness is annoying.

Lee

Different strokes, as they say. I don't think there's anything wrong with sulfiting prior to fermentation, even if ML is wanted - although, like you, I'm not sure why we were trying to prevent it. I sulfite the must before fermentation as a matter of course and have even used RC212 as in this case with no problems. Many, if not most commercial wineries do it, too - it's a good way of suppressing spoilage yeasts like brett, doesn't bother most cultured yeasts assuming that we're talking about 40-50 ppm and will all be gone after primary fermentation and so shouldn't cause problems with ML either. I'm still not clear when the sulfites were added here or how much - the OP said he "sulfited the wine". If that means after fermentation had started rather than before or if levels were high, though, I agree they could indeed have been part of the problem.

- Mark W.

My experience with racking off the gross lees that soon is not that great - if the wine still ferments at the time, it ususally slows down markedly and more often than not ends up off-dry. The MLF also often stops for me before finishing with this approach. I'm wondering if this depends to some extent on the size of the containers because 6gal carboys behave better than 1 gal jugs, so maybe barrels would not have these problems? In any case, in balancing the stuck ferments with the danger of H2S, I let the wine finish alcoholic fermentation first before racking off the gross lees - IF there are no off smells.

For the original question, if it's still going I'd probably just leave it. RC212 at this stage will be pretty slow. It might not finish completely dry, but it should go down to a decent level. I tried fresh yeast starters and yeast cakes from active fermentations before and didn't get much out of it - a small drop in sg over several weeks was a typical result.

Pp

Lee, keep in mind that though we often thing of SG 1.000 as sugar-free

- and it would be before fermentation - a completely dry wine is usually in the neighborhood of SG 0.992. I'm not sure what the exact conversion is but at SG 1.002 I would think you're looking at 2 to

2.5% residual sugar, so it should come as no surprise that your wine is tasting pretty sweet.

FWIW, although I've been lucky enough to avoid a stuck fermentation in my own limited home winemaking career, I've seen fermentations restarted at commercial wineries and perhaps I can add to the bag of tricks you're collecting from some of the others. One of those tricks is to add yeast hulls - as I understand it, they are supposed to bind yeast toxins (if that's the right word) left from the first fermentation. Also, fermentation is much more difficult to get started than it was in the original high sugar/low alcohol environment. So rather than hydrate and then pitch all at once, another trick is to feed the hydrated yeast yeast just a little of your wine at a time, doubling and then doubling again so that the shock isn't so great. And finally, of course, you want to choose a yeast with very good alcohol tolerance.

As I said, FWIW - I hope that helps.

- Mark W.

That sounds like what I was describing in my previous post in this thread - did you rack off the gross lees after pressing? My impression is this can reduce the yeast population too much, and it never recovers to its former strength. (As a side note - I used RC212 on a mix of red/black currant and pressed at 1.020+ after about a week of fermentation. This was in July/early August, and the wine is still fermenting! So the yeast strain could also be a factor here.)

As for the drop in sg, that's not bad. I've had a Merlot this year that was pressed at 1.000, went down to 0.9985 in 3 days, at which point I racked off gross lees. After that, the ferment slowed down noticeably - there were bubbles and regular activity in the airlock, but it's taken about 5-6 weeks now to get down to 0.994.

As for the sweet taste, 1.002 is pretty sweet - about 2.5-3% residual sugar, and it's more noticeable in the reds than say in Germanic whites. If your sg keep dropping, just give it time.

Pp

FWIW, my reason for not adding SO2 at crush is that I want as much of the browning as possible to occur _before_ fermentation, so that it gets carried down with the lees. I'm speaking mainly of white wine, where browning/pinking is a much more worrisome issue. For reds, I guess sulfiting at crush is OK - but I usually don't do it because I want a smooth ML running concurrently with the primary.

My whites normally end up with a somewhat golden color by the time they are ready for bottling, but much of that is from lots of new oak. They definitely don't look or taste oxidized.

Tom S

I thought it was pretty clear that we were talking about wine that had completed at least its primary fermentation. He was pressing it after all. Pressing while the wine is still sweet isn't a good idea if you're making a dry wine.

Tom S

My understanding is this wine was pressed at 1.010, after which the ferment slowed down. I know lots of people who press their reds around that time - although I agree with you that it's harder to ferment out to dryness.

Pp