Stopping fermentation

Potassium sorbate prevents yeast cells from budding (reproducing). Consequently, sorbate is only effective when the yeast population is small. Chill your wine, stop fermentation and let the yeast settle. Then rack the wine off of the yeast lees to reduce the yeast population. You may need to repeat this operation a couple of times to get your wine clean enough for sorbate to be effective. Good luck, Lum Del Mar, California, USA

Mr. Lum what about sterile filtering after you rack?

Not really an option for me or I would have done it already. Major lack of funds ;-)

That is the way wineries stabilize wine containing residual sugar. But, the bottle filler, corker, corks, bottles, etc all must be sterile as well.

I went through this this year but couldn't get the temperature cold enough to stop the ferment completely, so I've also added the sorbate to create worse conditions for the yeast. I then fined within next 2 months with bentonite and Sparkalloid and finally filtered with the #2 Mini Jet filter.

My question is - is the sorbate I added early in the process still fully active? The wine is clear and there doesn't seem to be any activity, and I'm trying to keep the sorbate additions to minimum as I am sensitive to its smell, so I'm hoping the answer is yes.

Thx,

Pp

I don't know. But I suspect there is little sorbic acid left in your wine.

As others have said, sorbate works by preventing yeast budding or reproduction, not by killing the yeast. If you slow the yeast activity down in some way such as chilling, the yeast and other substances will settle to the bottom. Yeast activity and CO2 generation keeps things in suspension. You can help by using a fining agent to take things out of suspension and forcing it to the bottom after yeast activity has slowed or stopped. The faster it is cleared the less likely the yeast will kick off again before you are ready. I like SuperKlear for light or white wines. it can clear a wine overnight.

Once it is pretty much clear, rack it off the sediment and you will leave the yeast behind. Now you can treat it with sorbate and sulfite and prevent the few remaining yeast from reproducing again. Let it set for a month to allow any further sediment and yeast to drop out and bottle. By this time there will be so few yeast that they will not cause a problem However, if you did not treat with sorbate, over time, a few yeast can reproduce and become a big problem.

Ray

I hate using sorbate too but use it anyway since there is no way I can guarantee sterility in my cellar, it's impossible on the scale I work at. I make some wines sweet for others although I can see why they like them. ( It takes a lot for me to admit some wines are better sweet, but I'm doing that here....)

Why not go through the No 1 pads (the green ones) and sorbate at the minimum level? I can't guarantee it's going to work but it's what I would do. You could just rack and take one bottle off and warm it. Racking and warmth always seem to get things going if they are going to. You could use that as a guide for your decisions.

Joe

Thanks, Joe, that's basically what I'm trying to do. I think the finest pads are #3 and not #1 - not sure about the colour - I'm assuming those are the ones you meant? I used them only once before on a white and although it looked very clear, I had a huge amount of bypass and had to run it through the filter 3-4 times to avoid losing too much wine. I also picked up some metallic taste from the bypass wine - I think it's running over the screws somewhere in the filter, so taken together, I've decided not to use the fine pads on MiniJet. It might be somehing about my filtering technique but as far as I can tell, I'm doing things correctly per instructions.

The particular difficulty in this case is that having used the sorbate before it should be used, I don't know what it the minimal level - that was the gist of my question. If all sorbate I had added is still active, I am at the minimum level already; if it's partially or completely gone, I need to add up to the same amount I already added. And since I can't measure it, I might end up with the sorbate taste/smell that I hate.

The wine has been sitting in carboys and some bottles for 3 weeks now in my living room after the filtering and I'mnot detecting any signes of activity, so I think I'll risk it. Next time though I'll wait with the sorbate after the wine clears up.

Pp

I follow you, I'm in Amarillo now so can't speak to what I use as the minimum level but should be home tomorrow.

I have bypass problems on my mini-jet too, I really tighten mine up at first. What I do is run the nut in until it just applies a little pressure, bring the other up to that point and then count turns keeping them the same. I take it as tight as you can get by hand. That usually does 7 gallons with minimal bypass, after that it's iffy. I run the bypass line into a separate gallon and suck it back out if It starts to get out of hand. I have only done whites with the 'sterile' filter, all I remember is it's green printing. The middle one is red, I have a coarse one that is blue but have never used it.

I would chance it myself; if it restarts you can always put it back in carboys and let it finish. I don't know any cheap way to measure sorbic acid content either so follow your dilemma. It sounds still, a mini-jet should have stirred things up. It's at room temperature now so what about warming one of those bottles up to around 100 F with a heating pad or a low wattage incandescent bulb? If it doesn't go at that point I think you are OK.

Joe

I've been reading this thread and decided to comment on a couple of points.

First off, you shouldn't find sterile filtration to be that daunting. I've done it at home and had no problems with re-fermentation in vitro. It isn't necessary to remove every last yeast cell before bottling. That's pretty much impossible to accomplish even at a commercial winery. You do need to run the wine through a sterile membrane filter though, and they are expensive. Fortunately, they are also reusable if used correctly and will last a_long_ time if you run nothing but well filtered wine through them. You also need to be sure the wine has adequate sulfite prior to bottling.

Secondly, if you folks are having trouble with filter media loading up on you, it's probably because the wine wasn't clarified sufficiently prior to filtration. The best candidates for filtration are wines that really don't _look_ like they need to be filtered.

Here's a little tip: A light bentonite fining (1 or 2 lbs./1000 gal.) aids filtration by dropping out mucilaginous sugars that are invisible to the eye, but tend to blind filter media. Most winemakers don't think reds require bentoniting, but you and the wines certainly can benefit from it.

Tom S

, I might end up with the sorbate

Hi Pp

Try switching to Sodium Benzoate. I'm sure you will be pleasantly surprised. HTH

Frederick

Just as long as there is no ascorbic acid in the wine. Apparently ascorbic acid can break down benzoate into benzene, a carcinogen. It has been fairly big in the news lately.

Frederick - In your experience what concentration of Sodium Benzoate is needed to prevent fermentation in a sweetened wine? Bill Frazier Olathe, Kansas USA

Here's my recent story. I make Vidal wine sweetened with reserve juice I save at crush time in late September. The reserve juice is settled, racked clear, treated with SO2 at 100 ppm and K sorbate at 208 ppm. The juice is stored near freezing until it's used to sweetened the finished dry wine.

The Vidal wine was fermented to dryness with DSM Fermiblanc yeast, fined with bentonite, cold conditioned, racked clear, fined with Polyclar VT and racked again. I noticed a slight fermentation so I added Lysozyme to stop it (Note: I always have spontaneous ML fermentation in my cellar). In February 3 gallons of dry wine was mixed with about 3/4 gallon reserve juice to make an off dry wine at SG 1.006 with a fresh, grapy aroma and flavor.

The sweetened wine was passed through 1.0 and 0.2 micron cartridge filters. The filtered wine developed a haze which I suspected was a protein haze from the juice. I moved the wine to a refrigerator at 35F . After a week it cleared nicely and was racked. At room temperature there was very slow bubbling through the air lock. No residue formed on the carboy bottom. No bubbles could be seen rising in the wine.

I added tartaric acid to lower the pH to 3.2 and added more K sorbate to increase the concentration to 264 ppm. Sulfite measured at 60 ppm. After two weeks the bubbling stopped and air lock liquid levels equalized. The few remaining yeasts expired.

This morning we bottled the wine two months after adding the reserve juice, K sorbate and sterile filtering. As I told my grandson, who was at the filler, you just have to be patient when making wine.

Bill Frazier Olathe, Kansas USA

Hi Tom, The Mini-jet filters are really small, they are only meant for 5 gallons of wine. The pump has no volume capabilities and develops very little pressure. That said it works if you are willing to play around with it. I usually get 10 gallons through a filter before it leaks too much and only filter clean wine.

As to the membrane filter, you already talked me into using a barrel and making more wine from grapes, I guess this had to be next... :)

Seriously, I may look into that but my concern is used bottles. I'm wondering if I wash them well and treat them with B-T-F at their recommended levels if that would be good enough. That has always been my concern. I am pretty sure I can get the wine right, it's what I'm putting it into that concerns me. I give most of the sweet wine away so I'm just not going to use new bottles, I'm just not _that_ nice a guy...

I will always be making at least 15 gallons of something sweet so the membrane filter may be worth doing. I have also been reading about some of the pasteurization techniques people are using commercially. It seems there are several way people are doing that and some of those are in reach of a home winemaker.

Joe

Hi Joe, I bring home about four cases of dirty bottles from the winery tasting room each week. I remove the labels by placing the bottles in half of a poly drum filled with plain water. Then I wash the bottles in the kitchen sink filled with hot water and about two cups of Costco dish washing powder. I air dry the bottles and then place them points down in clean cardboard cases. At bottling time, I remove the cleaned bottles from their cases and place them on the bottle filler without any further treatment. I bottle about 200 cases of wine each year and I have never had a problem traceable to using rewashed glass. (Bugs that can survive on clean glass, can't survive in wine). Regards, Lum Del Mar, California, USA

Hi Lum, I guess I'm just too paraniod about sweet wines. Since I give all of them away I'm working on the 'better safe than sorry' side of the street.

Joe

Joe, I have had my problems with RS in wine. It sounds like your on the right side of the road. Lum