learning question

[saramc]

If I recall the MSDS for potassium sorbate says it is easily soluble in cold water. I simply dissolve it in equal amount of water, then I stir the crushed KMS into the sample of wine in my wine thief and all is good. I have had issues of sorbate not dissolving when added directly to wine, I really should have written down which wines those were...regardless I no longer directly add either any longer. Just my comfort zone.

 

[Turock]

If you don't get the sorbate dissolved evenly, you may have some bottles that don't have enough in them. Very important to get it distributed thruout the wine. Whether you do it dry or mix in water---whatever works for you is the best way. Those little pellets of sorbate really don't dissolve very well. That's why we crush them with a mortor and pestle.

 

[weaverschmitz]

Sorbate in port

I've always added sorbate dry and haven't had any problems. Until this weekend when I wanted to bump up the sweetness of a mulberry port and added some sugar along with sorbate. It did not dissolve. Based on the comments in this thread I'll dissolve in warm water going forward. However, I'm wondering what I should do now about the sorbate that isn't dissolving?

 

[jamesngalveston]

leave it and rack it off.....never add sorbate to an uncleared wine.

 

[Pumpkinman]

never add sorbate to an uncleared wine

James, I've never heard this before, where did you find this info?

 

[cmason1957]

James, I've never heard this before, where did you find this info?

Oh good, I am not the only one to doubt this but if wisdom I have heard from others before. I think to me instructions. They always have you add the sorbate before clearing.

 

[jamesngalveston]

following turocks lead are running wolf..not sure which...but it makes sense.

http://nanaimowinemakers.org/Notes/Sorbate.htm
http://en.wikipedia.org/wiki/Potassium_sorbate

 

[jamesngalveston]

pumpkinman and cmason...i know both of you are very good winemakers with much knowledge, here is some room for thought...
the least yeast cells, the better the sorbate works.
a clear wine has less yeast cells.
also...i think lot of times when folks have wine that is hard to clear it is because of the sorbate added before while cloudy.


this is just my opinion and can not find any evidence of it.
we all know there is a negative and positive charge in the wine particulates...could sorbate change that in some way, are build a wall around the yeast cells make them lighter and harder to drop...
what you think.

 

[jamesngalveston]

(A) Ferment the wine until it is completely dry. Just before bottling time, when the wine is clear and stable, add 250 milligrams per liter of potassium sorbate. Raise the molecular sulfur dioxide level to 0.8 milligrams per liter and add the desired amount of sugar or sweet reserve. Potassium sorbate stops yeast cells from multiplying. It does not stop fermentation, so sorbate is only effective when added to clear wines (containing only a few yeast cells).

 

[Turock]

The reason you don't add sorbate to an unclear wine is because there are too many yeast cells present for it to work properly. The over- abundance of yeast cells will overwelm the sorbate. All white papers on sorbate do a good job of explaining this, but I'm sure many people have never researched sorbate. Many people add sorbate to wine shortly after they get it over in the secondary saying that they are "stabilizing" the wine. Well, nothing is further from the truth.

For sorbate to prevent refermentation when you are backsweetening, you must first have the bulk of the yeast cells removed thru racking. Otherwise, there are so many yeast cells that the sorbate can't fully work and you will have a very slow re-fermentation going on. And bulk aging is the only tactic that stabilizes wine because the sediment that falls out of a wine is all the unstable components. So getting these off the wine is what gives stability.

The only time you add sorbate before clearing is with a kit. But that is the only time you should do it. For non-kit wines--don't sorbate until you have the wine clear.

weaver--If you let the carboy sit until the sorbate is hydrated, then stir, it should go into solution. Go to Bed Bath and Beyond and get yourself a mortor and pestle and crush that sorbate up!! It dissolves so much better--or put it in some water first. Whatever works for you is fine. But just tossed into the carboy whole---well, they don't like going into solution in a cool liquid like wine.

 

[cpfan]

I don't want to get into an argument about sorbate before or after clearing because I suspect it's one of those "ask 10 winemakers get 12 responses type things". However, ....

1) kits have you add the sorbate prior to the clearing agents (as already mentioned)

2) if there is a tiny bit of sugar left that has not fermented for some reason (eg alcohol %age), or is fermenting very slowly (eg temperature too low) [YES, I know that these are picky picky situations], then the yeast may keep working and interfere with clearing. Therefore sorbate prior to clearing should shut down the yeast and assist in the clearing.

So, since I'm a kit guy, sorbate (when I use it) goes in before the clearing agents. If you do different, and it works....GREAT!

Steve

 

[Runningwolf]

Again many ways to get to the finish depending on who you talk to. For years I always added meta/sorbate right after racking off fermentation since I started off with kits just like cpfan does, I NEVER had an issue.

With that said TODAY I add sorbate, meta and sugar at the same time just days before bottling.

OK YA'LL ready for this one? Occasionally I'll add 1/2%rs sugar (1.002sg) to a red. I add NO sorbate to this.

 

[GreginND]

Again, sorbate does not shut down yeast. All living yeast will continue working as long as there is sugar and they I'll live out their normal lifespan.

Kits are bottled pretty early. I tend to age wines a year or more before bottling. Thus I only add sorbate and sweeten a few weeks before bottling. If you add sorbate near the beginning and age it for a year, it may have decomposed and become less effective when you go to bottle.

 

[GreginND]

OK YA'LL ready for this one? Occasionally I'll add 1/2%rs sugar (1.002sg) to a red. I add NO sorbate to this.

Yes, you can get away with that for a while. Presumably the yeast population will be extremely small after aging your red. But I wouldn't trust it for years in the bottle and definitely not on a commercial product without sterile filtration.

 

[Turock]

Anyone who questions sorbate useage should go read some white papers on it for yourself. I think this is the number one addition to wine that is the most misunderstood.

When doing kits--follow the instructions because they are made different than scratch wines. But using sorbate before clearing on non-kit wines is wrong because it often causes problems.

If yeast cells are present---and they always are---you risk re-fermentation when adding sugar and no sorbate. You will STILL have a slight and very slow re-fermentation but you may not notice it and it may not be enough to blow the cork. But this is always risky and not the best practice.

 

[Runningwolf]

Commercial it is! They also do this a lot in California. Keep in mind most yeast has been racked off, died off or weaken. The wine has been aging at least a year. Did you ever try to restart a fermentation at this point? Extremely difficult. Last stop is a .45 filter followed up with an absolute filter as Greg mentioned.

I would never go over 1/2% rs sugar when doing this.

I DO NOT RECOMMEND THIS PRACTICE AT HOME, but I do it with my .45 micron filter on the Enolmatic. Not thinking outside the box, just pushing the limits.

 

[jamesngalveston]

I can not find the white paper, but I read where sorbate attacks the cells of the yeast, and surrounds the cell with a barrier of some kind, thinking out of the box....
when this cell is being protected by the sorbate, doe the cell fall out as fast as sediment...are is the structure neutral....meaning not positve are negative and prevents from clearing a cloudy wine.
Just my opinion.

 

[cmason1957]

Here is a link I found to a very approachable white paper on sorbate use.

http://enology.umn.edu/2011/02/23/potassium-sorbate-as-a-wine-preservative/

Important points I got from it, if you don't care to click and read.
1) Commercial wineries seldom use it. They sterile filter, which remove all dead yeast cells.
2) I think we all knew this one, don't need to add to dry wines.
3) should be used when levels of yeast are smallest, (not like wine kits have you add).
4) always breaks down over enough time.
5) amount used depends on pH. (I have to say this one surprised me)

 

[Turock]

I thought that filtering only got rid of 80% of the yeast cells.

 

[jamesngalveston]

cmason, i read this in the article you posted a link to.

The amount of sugar in the wine has no effect on the amount of sorbate needed. The only concerns are pH, alcohol, and the initial population of yeast cells (which should be less than 100/mL – make sure the wine is very clear before adding K-sorbate).