Can I Stop Fermentation Early???

When I take a sg reading before putting into a secondary, I drink the sample. I really, really like it at that point.....little alcohol, fruit flavor, sweet, and a little bubbly. Is it possible to stop it at this point with potassium sorbate or something? Or isn't there enough alcohol to preserve it? Or is there some other reason I couldn't stop it there?

Yes, you can stop the fermentation with potassium sorbate.

What are the OG & current SG?

Potassium Sorbate will not stop an active fermentation, it only prevents a wine from re-fermentation. You add Potassium Sorbate to finished wines before bottling to reduce the possibility of re-fermentation.

How To Stop A Fermentation

You can try, but I'd guess that you wouldn't be very sucessful. It's hard to get a fermentation stopped, once it's going. It's like stopping a train. You can try potassium sorbate and campden tablets, but it'd be a better bet to allow fermentation to finish, and then sweeten it afterwards by stabilizing with campden and sorbate when finished.

Do you suppose freezing the must would stop fermentation?

ms8miranda said:

Do you suppose freezing the must would stop fermentation?

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Yes. Until it thawed.

You could try radiation.

YooperBrew said:

Yes. Until it thawed.

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I thought I read that freezing would kill the yeast (accept maybe 1 or 2 hardy ones).

ms8miranda said:

I thought I read that freezing would kill the yeast (accept maybe 1 or 2 hardy ones).

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Nope. Heating it to 125F will kill off most yeasts, but it will also drive off flavors and odors that you don't want to drive off.

The only way to effectively make sweet wine or mead is to give it enough initial sugar to get to the alcohol level you want, add campden tablets and sweeten as desired.

ms8miranda said:

I thought I read that freezing would kill the yeast (accept maybe 1 or 2 hardy ones).

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I've stopped fermentation of cider by cold crashing. Should work with wine. Just make sure not to siphon off any of the yeast cake that forms at the bottom.

you could always add some brandy

Confucius said:

I've stopped fermentation of cider by cold crashing. Should work with wine. Just make sure not to siphon off any of the yeast cake that forms at the bottom.

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Doesn't work with wine or mead. They age longer in the bottle, and if there's any living yeast left, it can have time to multiply, begin fermentation in the bottles, and cause them to explode. Been there, done that.

Carthax said:

Doesn't work with wine or mead. They age longer in the bottle, and if there's any living yeast left, it can have time to multiply, begin fermentation in the bottles, and cause them to explode. Been there, done that.

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See, I figured that might be the case. All the meads and wines I've done, I've either left dry or overwhelmed the yeast.

Sterile filtering is an easy way to stop fermentation.

gregbathurst said:

Sterile filtering is an easy way to stop fermentation.

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Yep the only thing I have ever done that works. but you will loss flavor and the 2 filtering it takes to get it sterile will drive off the co2 and you will loss the sparkle you said you like.I say ferment it out , back sweeten and mix it with sparkling water when you drinkmit

what kind of equipment would you need to sterile filter? What exactly does potassium sorbate do?

Potassium sorbate inhibits yeast reproduction. It doesn't kill them but they can't reproduce. That's why it doesn't really work in an active fermentation- there are plenty of yeast and they don't need to reproduce. But if you wait until fermentation is finished, the wine clears, and the yeast fall dormant to the bottom of the fermenter, you can rack the clear wine off of the lees. There are still some yeast in suspension, but not nearly as many, and if you add the sorbate they can't reproduce. This means that fermentation shouldn't restart.

This doesn't work well in young wines, because there is still plenty of yeast in suspension, but in older clear wines that have been racked a couple of times it works well. Sorbate works better in the presence of sulfite, so they are usually added at the same time.

In a wine that is possibly going to undergo malolactic acid fermentation (grape wines and apple wines most often), you don't want to sorbate it until it's sulfited first. If it starts MLF, the sorbate alone will cause a terrible geranium smell and ruin the wine. If it's sulfited, MLF shouldn't start.

what amount of PS would you add to Ed Wort's Apfelwein?

JamesM said:

what amount of PS would you add to Ed Wort's Apfelwein?

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Bumping this because I'm in need of this very answer!

One crushed campden tablet dissolved in 1/4 cup boiling water and 1/2 teaspoon of potassium sorbate, per gallon of wine.

Much appreciated Yooper!

How about this... going back to original question about stopping the fermentation early.

What if during the SG readings and sampling you find the taste where you like it and still approximately 1% of fermentable sugar left you decide to go ahead and bottle it. Understanding of course that if the cider is left to ferment in the bottles, they will explode. However, and this is where my question comes in, go ahead and let fermentation continue in the bottles until the proper card level has been reached and then pasteurize the bottles to kill the yeast inside while leaving the carb level good.

The pasterization method I would be using would be this:
https://www.homebrewtalk.com/f32/easy-stove-top-pasteurizing-pics-193295/

Thoughts....? Opinions....? I need feedback regarding this. I have made batches of cider where I let ferment till dry, back sweetened and bottled, but found the end result was not as good as when sampling the cider during active fermentation when apple flavor was still good, sweetness level was there and still could detect the alcohol.

backsweeten with a touch of cider instead of pastuerizing, it tastes very nice.

spacemanzero said:

How about this... going back to original question about stopping the fermentation early.

What if during the SG readings and sampling you find the taste where you like it and still approximately 1% of fermentable sugar left you decide to go ahead and bottle it. Understanding of course that if the cider is left to ferment in the bottles, they will explode. However, and this is where my question comes in, go ahead and let fermentation continue in the bottles until the proper card level has been reached and then pasteurize the bottles to kill the yeast inside while leaving the carb level good.

The pasterization method I would be using would be this:
https://www.homebrewtalk.com/f32/easy-stove-top-pasteurizing-pics-193295/

Thoughts....? Opinions....? I need feedback regarding this. I have made batches of cider where I let ferment till dry, back sweetened and bottled, but found the end result was not as good as when sampling the cider during active fermentation when apple flavor was still good, sweetness level was there and still could detect the alcohol.

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Yes, pasteurization is an effective method of stopping the fermentation early that is easy to do. The drawback of pasteurization is that it may effect some of the subtle flavors. Other methods of making a sweet cider/wine without resorting to sulfites or sorbates include:

1. Fermenting to dryness and then back sweetening with a non-fermentable sugar such as xylitol. Xylitol occurs naturally in fruits and berries, such as pears and strawberries. Adding pear juice to your cider mix has the same effect, you will end up with a sweeter product even if fermented to completion.

2. Cold crashing and multiple rackings will leave you will a cider that is less dry.

3. Cold crash at the sweetness you like followed by sterile filtration or centrifugation.

4. Or you could ferment to dryness, age the cider well, then pasteurize or sterile filter and backsweeten with regular sugar. Making a DYI filter is not that hard or expensive. You would need a 0.5 - 0.65 micron sterile filter to filter out 100% of the yeast. They are sold at many brewing suppliers.

Perhaps the reason your cider was not as good when you let it ferment to dryness is that you didn't let it age long enough. In The New Cider Maker's Handbook, Claude Jolicoeur recommends aging for 6 months to a year after the first racking at cool cellar temperatures or lower over the Winter, and then aging in the bottle for another 6 months. For cider there is another fermentation called the "malolactic fermentation" (MLF) that can occur in the Spring when the weather starts to warm up again. This is the conversion of malic acid in apples to lactic acid, which is a less aggressive and smoother acid, by lactic acid bacteria (LAB). MLF can mellow, improve mouthfeel, bouquet and aroma. LAB have little tolerance to sulfite, and can be inhibited at sulfite levels as low as 10 ppm, so if MLF is desired sulfite should not be added before MLF is completed.

MLF can occur spontaneously when the weather warms up in the Spring or by inoculation with commercial LAB cultures.

Great pasteurization method. I'll have to give that a try.

Joseph