Cold crashing

[wineview]

What is an acceptable F temperature for cold crashing? Thinking of putting some wine outdoors. Please be specific about daytime and nighttime temperatures.

 

[ChuckD]

I had mine in the garage for more than a week when the nights were in the mid 20’s and days in the upper 30’s. The wine was at 28 to 30 and never started to freeze. I’m not sure what the freezing point is for 14% alcohol but mine never even started to get slushy.

 

[winemaker81]

There is no one answer to your question as this is a diverse subject.

The important question is what are you trying to accomplish? There are two main points -- one is preventing tartrate crystals in wine and the second is reducing acid levels. These are not the same thing.

If you're trying to prevent tartrate crystals from forming, chilling the wine to the 50's F may be sufficient. My cellar is typically 58 F in the winter and wines that I don't expect may drop crystals. None of these wines have dropped crystals after spending 2 weeks in the fridge at 40 F.

If you have a high acid wine, chilling the wine may drop crystals and reduce the tartaric acid. Colder is better down to freezing.

I've read several studies about chilling the wine down to the freezing point of wine -- which is NOT a constant value. The freezing point of wine depends on the ABV and other solids in the wine.

The studies I've considered valid state that lowering the temperature below 32 F produces no additional value. These studies plus my own practical experience indicate that getting the temperature below 40 F and keeping it there 1 to 2 weeks drops the most tartrate crystals. Closer to freezing produces more results, but whether or not that matters depends on your situation.

The more consistent your temperature, the better. Big temperature swings will reduce effectiveness.

 

[wineview]

There is no one answer to your question as this is a diverse subject.

The important question is what are you trying to accomplish? There are two main points -- one is preventing tartrate crystals in wine and the second is reducing acid levels. These are not the same thing.

If you're trying to prevent tartrate crystals from forming, chilling the wine to the 50's F may be sufficient. My cellar is typically 58 F in the winter and wines that I don't expect may drop crystals. None of these wines have dropped crystals after spending 2 weeks in the fridge at 40 F.

If you have a high acid wine, chilling the wine may drop crystals and reduce the tartaric acid. Colder is better down to freezing.

I've read several studies about chilling the wine down to the freezing point of wine -- which is NOT a constant value. The freezing point of wine depends on the ABV and other solids in the wine.

The studies I've considered valid state that lowering the temperature below 32 F produces no additional value. These studies plus my own practical experience indicate that getting the temperature below 40 F and keeping it there 1 to 2 weeks drops the most tartrate crystals. Closer to freezing produces more results, but whether or not that matters depends on your situation.

The more consistent your temperature, the better. Big temperature swings will reduce effectiveness.

I’d like to reduce some acidity. Your answer gives me a better idea when to put the wine outside in upstate NY. Rather than lugging a five gallon carboy up and down steps, I plan to break it down into gallon jugs with screw caps and place them on the back deck. Probably best to wait until November for more consistent temperatures.

 

[winemaker81]

If you have an enclosed area, it's safer. My porch in Rome (circa 1990) was typically 32 to 40 in December through February. Outside can be too variable.

 

[wineview]

If you have an enclosed area, it's safer. My porch in Rome (circa 1990) was typically 32 to 40 in December through February. Outside can be too variable.

I have a detached garage with concrete floor. Maybe in there.

 

[winemaker81]

I have a detached garage with concrete floor. Maybe in there.

Put a layer of something between the carboy and the concrete. Glass on concrete can produce stress cracks with repeated contact.

 

[ChuckD]

I have a detached garage with concrete floor. Maybe in there.

I put mine in the corner of the garage… two shaded block walls. Then I covered with a large box with two sides cut out. Very stable temps that way. And yes. Put cardboard under it for cushioning and insulation.

 

[winemaker81]

I put puzzle exercise mats (interlocking) on the floor (vinyl tile over concrete) where I place my carboys. It's a great cushion.

 

[Rice_Guy]

There is an effect on crystal size. Holding at close to freezing will produce a large film that is easy to rack off of. Actually freezing juice or wine produces a fine dust which needs to be separated like lees. Daily cycling should promote growth of larger crystals that are easier to separate.
On my part I freeze a lot of juice making the dust, but I want a good separation it goes in an unheated Wisconsin garage in January.

 

[wineview]

I put mine in the corner of the garage… two shaded block walls. Then I covered with a large box with two sides cut out. Very stable temps that way. And yes. Put cardboard under it for cushioning and insulation.

Can you explain what sides of the box are cut out. I was thinking of putting gallon jugs inside six gallon juice buckets.

 

[ChuckD]

Can you explain what sides of the box are cut out. I was thinking of putting gallon jugs inside six gallon juice buckets.

Two sides of the enclosure was concrete wall and two sides and the top were a cardboard box.

To keep it dark and moderate swings in air temperature.

 

[ChuckD]

There is an effect on crystal size. Holding at close to freezing will produce a large film that is easy to rack off of. Actually freezing juice or wine produces a fine dust which needs to be separated like lees. Daily cycling should promote growth of larger crystals that are easier to separate.
On my part I freeze a lot of juice making the dust, but I want a good separation it goes in an unheated Wisconsin garage in January.

I didn’t know this but experienced it with cellar aged (50-60F) vs cold stabilized (30F). The cellar crystals
We’re a grainy sediment in the carboy…The crystals in the cold stabilized wine could be used for spiritual healing

 

[wineview]

I didn’t know this but experienced it with cellar aged (50-60F) vs cold stabilized (30F). The cellar crystals
We’re a grainy sediment in the carboy…The crystals in the cold stabilized wine could be used for spiritual healing

I’ve seen that grainy sediment in my cellar.

 

[wineview]

If I were to place gallon jugs in six gallon plastic buckets on a concrete floor in my garage, would the bucket be enough of a buffer between the glass gallon jugs and concrete?

 

[ChuckD]

It should. I use the cardboard for a thermal buffer, but more importantly for protecting the glass. I’ve seen glass shatter with relatively light hits on concrete.

 

[wineview]

I can easily put cardboard under the buckets.

 

[wineview]

After cold crashing, is it best to rack and bottle immediately and not let the wine warm up?

 

[winemaker81]

After cold crashing, is it best to rack and bottle immediately and not let the wine warm up?

Supposedly once the crystals form, they don't easily dissolve. However, my habit is to rack the wine before it warms up.

 

[VinesnBines]

After cold crashing, is it best to rack and bottle immediately and not let the wine warm up?

As Bryan will testify, acid will drop and form crystals without cold crashing. In particular my Vidal will form crystals from the start, hence my confusion about crusty yeast colored flakes when I racked. Warming doesn’t make the crystals dissolve.