Is it possible to stop fermentation

This may seem a bit "off the wall" but I am researching if it is possible to essentially prevent fermentation in freshly squeezed grapes; just the opposite of what is desired in making wine. I realize that in the time it takes to squeeze the grapes and collect and bottle (if one chose those steps in order quickly) would still result in fermentation beginning, but if one wished to stop the fermentation at that stage would it be possible and how?

Thanks.

Reply to
Colonel Blip
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A couple of possibilities come to mind. You could filter the juice with a tight membrane filter and remove all of the native yeast and bacteria. This method requires special equipment and a course filtration will be needed before the membrane filter could be used.

Or, you could pasteurize the bottled juice just before sealing the bottles. A temperature of 160 - 170 F for two or three minutes might kill the native yeast and bacteria. This method requires special heating equipment and the juice must be mixed in some way to maintain a uniform temperature.

Of course, you could always freeze the juice.

Reply to
Lum

Irradiation will probably do it you have the facilities and nerve

Reply to
Rex Franklin

I have read where it is possible to boil the grape must to make something akin to molasses and seal it (I suppose one could add something like potassium metabisulfite as well) and, since no yeast is added, could prevent fermentation. Is this true?

Reply to
Colonel Blip

Boiling should pasteurize the juice and kill the microbes, but the character of the fresh juice will be changed.

Large quantities of potassium metabisulfite can inhibit fermentation, but the quantities needed are so large the juice would not be useful for most applications.

Reply to
Lum

People have done this for years. Use standard canning techniques. You will need to strain, and filter the juice to get rid of solids. Cook it to kill anything in it. And you will need to use true sterilization rather than sanitation used in wine making. But search the web for canning juice.

Ray

Reply to
Ray

but after that it will not taste the same as "fresh" grape juice -- the heat/pasteurisation is a huge part of why red wine kits never achieve the same quality! You finish up with that coked fruit taste!

Reply to
Pinky

For "coked" read "cooked" !!!!

Reply to
Pinky

I have never eaten any canned food that tasted like fresh. No surprise there. But if you want the stuff out of season, it is what people have done for years.

Ray

Reply to
Ray

Last year, I froze some fresh juice and reserved it to add back to completed wine to give a higher sugar content. In spite of all of my efforts at filtering and sulfiting, it still re-fermented in the bottle. The problem with most readily available filters is that they don't take out ALL of the yeast....just enough to fool you.

Lee

Reply to
LG1111

I know of several wineries in the Finger Lakes of NY that cold stabilize and then sterile filter their late harvest wines to stop the fermentation. The process does work, if the filter is fine enough.

How fine is that? Darned if I know -- I don't use a filter. :-) Seriously, if I recall correctly a filter that prevents anything greater than 5 microns (???) from passing is required. And the problem with the fine filters is that they also strip color and flavor.

On the few occasions that I sweeten a wine at bottling time, I add a fining agent, cold stabilize for a week, rack before it warms up, and then add sorbate to prevent a renewed fermentation.

Bryan

Reply to
Jake Speed

I think sterile filtration would do the trick. But 5 microns is WAY to coarse. The value may be (.5) as in 1/2 micron. Correct me if I'm wrong. Also in regard to previous comments about "cooked" taste. Does this apply to many of the "hot pressed" buckets of fresh juice? My understanding is that these reds are processed at a much higher temp than the better quality wine kits? Again, correct me if I'm wrong.

Reply to
Brewser83

Reply to
J Dixon

John, what brand of filter do you use? Is "Nominal" a brand name?

Lee

Reply to
LG1111

Reply to
J Dixon

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