AxisOfBeagles wrote:
> Have an '07 Viognier that (for the second time) is clouding when
> refrigerating.
>
> I put a one gallon carboy as a test batch into a 35 F refrigerator for 5
> days. it s cloudy. The wine is otherwise (not refrigerated, kept at
> around 59 in the wine cellar) brilliant clear.
>
> No pectic enzyme was used in vinification. Mlf was inhibited with
> lysozyme. Small bentonite fining some months ago. Free SO2 usually kept
> around 30 ppm. Wine is otherwise apparently clear, stable, and ready to
> bottle - but can't do so if it's going to cloud up when refrigerated!
>
> Most references cite protein hazing when wines are raised in temp. Can
> this happen when a wine is refrigerated? What can i do about it?
>


I don't see in your message any indication that you cold stabilized your
Viogner. Wines that have not been cold stabilized will precipitate
tartrate crystals when refrigerated; hence the cloudiness. This cold
instability cloudiness is a cosmetic defect; it doesn't affect the taste
of the wine.

Cold stabilizing a wine requires chilling it to below 'refrigerator
temperature' for an extended time. 27-28 F is ideal, taking 1-2 weeks.
Higher temperatures require longer times, perhaps a month or more. This
will drop out tartrate crystals, which settle on the walls and bottom of
the container. Then test the cold stability of a sample of the wine by
putting the sample in a refrigerator for two days or more, warm the
sample back to room temperature and look for cloudiness and/or
crystalline deposits. If you get those, the wine is not yet cold
stable, and you may have to seed the wine by mixing in cream of tartar
(about 1-2 gram per gallon) and repeat the cold stabilization process.
Once the wine tests OK for cold stability, you rack the wine, leaving
the tartrate crystals behind.

Some people combine bentonite fining and cold stabilization steps,
adding the bentonite just before chilling the wine. This saves one
racking step.

Please note that cold stabilization should be done after any blending
(blending two cold stabilized wines can re-introduce cold instability).

Bentonite fining improves heat stability; it doesn't affect cold stability.

Gene