Equipment (or not) for cold stabilization

[ChuckD]

Chuck you had a wild grape with a starting pH of 3.06 and seem to be at 3.2 lately. Since it is a northern I am going to guess that it is excessive as over 1% TA. Correct me if I am mixing threads.
Q? Do you want the finished dry? if so then you have to pull as much acid out as possible. , , , Do you want a sweet finished wine? if so you could leave some or all the acid in.
As far as a 3.49 wine, that is in a good place now. Elderberry has lots of bitter/ tannin flavor which will jump on the tongue magnifying any acid flavors. For balance if you push the TA up it will need lots of sugar.

? ? ? what is your sweetness goal? the TA will help predict how it comes out. (when you last racked wild grape did you taste the lees as is and with sugar?)

My wife and I generally prefer wines described as semi sweet. Although as we get more adventurous in our wine exploration we find our preferred sweetness level has been going down.

I have never tasted the lees of a wine. Is this a thing most people do and what are you looking for? I will sample the wine tonight to see where it is. Last I checked it was still pretty acidic tasting and had the strong foxy aroma. I have yet to oak the wine as I was waiting until the 3-month mark when I would rack it.

I’ll taste the elderberry as well.

This is one more reason I need to get some chemicals to do the TA testing!

 

[Rice_Guy]

* “pretty acidic” translates into the wine has too many molecules of acid. With your low starting pH this is expected. (Note sugar fixes acid, ex. a cola is about 10% sugar with the pH at 2.5.). I have had five gallon glass carboys in the garage starting at Christmas. If you are efficient at creating bitartrate do it soon or wait for 2023 or refrigerate it.

* there was a post above saying rack after pulling out wine diamonds. I hate instructions that run on the calendar instead of based on a functional trait as it has settled.
* functionally the purpose for the numbers is to set product specifications so newbies can run a factory. The TA numbers are useless if they don’t correlate with your tasting test so learn what tastes good.
* in the US market most wine is in the table wine category 1.002 to 1.010.

My wife and I generally prefer wines described as semi sweet.
I have never tasted the lees of a wine. Is this a thing most people do and what are you looking for? I will sample the wine tonight to see where it is. Last I checked it was still pretty acidic tasting and had the strong foxy aroma. I have yet to oak the wine as I was waiting until the 3-month mark when I would rack it.

I’ll taste the elderberry as well.

This is one more reason I need to get some chemicals to do the TA testing!

 

[ChuckD]

glass carboys in the garage starting at Christmas. If you are efficient at creating bitartrate do it soon or wait for 2023 or refrigerate it.

I was thinking it only took a week or so for cold stabilization? I do have an empty refrigerator in the garage that we use for excess garden produce. I can always use that if more time is required.

 

[Rice_Guy]

I have not seen any articles that describe the kinetics.
There are a few references on WMT that use week long times and Chuck off vinters puts his in a chest freezer for two weeks.
Some of the industry references mention being slow so they seed to speed and gum arabic is known to slow the process of growth.

I was thinking it only took a week or so for cold stabilization?

 

[winemaker81]

I was thinking it only took a week or so for cold stabilization? I do have an empty refrigerator in the garage that we use for excess garden produce. I can always use that if more time is required.

IME, at least a week. Since you can control the fridge (no danger of a temp drop harming the wine), leave it up to a month. 40 F or less will give you the most results. Research indicates 32 F will give you the strongest results.

A research paper distance runner sent me states that the same results are achieved with temps from 32 F down to the freezing point of wine. IMO 32 is the best target as there is no chance of the wine freezing.

 

[Ohio Bob]

What’s the difference between “most” results and “strongest” results?

 

[winemaker81]

What’s the difference between “most” results and “strongest” results?

Nothing. Poor choice of words on my part.

Cold stabilization is not an all-or-nothing action. I've had crystals drop at 58 F. The colder the temperature (to the above stated minimum), the lower the saturation threshold, and the more crystals will drop out of suspension.

It's also time dependent, e.g., chilling for a week will produce more crystals than for a day.

And, if there isn't excess tartrates, nothing will drop, regardless of other factors.

 

[Rice_Guy]

And, if there isn't excess tartrates, nothing will drop, regardless of other factors.

Cold crashing does not work on other crops as apple or gooseberry or raspberry. Grapes are the main species with tartaric acid and for potassium tartrate to crystalize there also needs to be an excess of potassium.

 

[Jim Welch]

I'm curious as to how people are doing cold stabilization (or temperature controlled fermentation for that matter), particularly for batches of (white) wine in the 15-30gal range. I don't have any suitable equipment right now so it seems my options are (in increasing order of cost):

(i) Leave outside (or in a covered location exposed to outside temperatures) in the winter. No cost, but little or no control over temperature
(ii) Some sort of fridge/freezer. Can control temperature but limited capacity - 1 carboy at a time, or maybe would fit a 60L/15gal tank?
(iii) Glycol chiller system with either in-vessel chilling elements or jacketed tanks. The best solution, but can get really expensive.

Any recommendations (or other ideas) welcomed!

I don't cold stabilize at least not yet but when I make white wines I do employ temperature controlled fermentation using the fermentation chamber (FC) I built for beer brewing years ago. It is not pretty and more than one of my friends have independently referred to it as being"MacGuyver-ed" up but I keep it in my basement where looks do not matter and it actually works like a charm, excellently even, if I don't say so myself! Using it it I've made award winning beers, temperature control is critical in beer making.

I will tell you how I made mine. I got a Kenmore deep freezer which is the same size as a dorm fridge, the hinges had gone bad and it leaked external air terribly but the refrigeration system still worked very well. Using a heavy duty solder gun with a de-soldering attachment I stripped the entire case and insulation. Then I made a large box with piano hinged doors using 2x3 studs for a frame and 1/4" luan plywood for the exterior sheathing. I well insulated it with 2 1/2" of insulation board, similar to Styrofoam. I use an STC-1000 temperature controller for temperature control but there are other similar possibly superior options. I also have a low wattage heater, made for reptile enclosures to provide heat when necessary. Using a small computer fan to constantly circulate air prevents temperature stratification. This FC is quite large, it will fit 3 half kegs with room to spare, when I make beer I make 14 gallon batches and ferment in 1/2 Sanke kegs which have a 15.5 gallon capacity. I specifically designed it for 1/2 kegs so it has a horizontal orientation but could have made it any shape or orientation.

I don't know if you want to go this route but if you'd like to see pictures of it I can post some here when I get home from a weekend at my beach place.

 

[tmcfadden932]

Tartrates fall out quicker as the wine gets closer to freezing. You can speed things up when the wine gets cold by adding cream of tartar to seed the wine. All cream of tartar comes from the wine industry. At freezing the tartrates will drop out in about three days. About 1/2 tsp per 5 gallons and stir well. You need to rack after the tartaric crystals drop out so they don't dissolve when the wine warms back up.

A friend worked in the wine industry in Australia, where they would put in 5lbs into a 5000 gallon tank of white wine and shovel out the crystals 5 days later.

 

[winemaker81]

A friend worked in the wine industry in Australia, where they would put in 5lbs into a 5000 gallon tank of white wine and shovel out the crystals 5 days later.

I assume Australian whites are acidic?

 

[tmcfadden932]

I assume Australian whites are acidic?

White wine usually is finished to about 3.45 pH and reds to about 3.6. The pros know when to harvest to hit those numbers after cold stabilization. Cold stabilization is done so that the consumer doesn't find "glass shards"' in their wine as well as adjusting the acidity.

 

[BarrelMonkey]

...I do employ temperature controlled fermentation using the fermentation chamber (FC) I built for beer brewing years ago...

I don't know if you want to go this route but if you'd like to see pictures of it I can post some here when I get home from a weekend at my beach place.

I am not the greatest DIYer in the world but I would be interested to see it! I do have an old dorm-size fridge (not freezer) with a bad door which might be adaptable as a fermentation chamber for whites...

 

[Jim Welch]

I am not the greatest DIYer in the world but I would be interested to see it! I do have an old dorm-size fridge (not freezer) with a bad door which might be adaptable as a fermentation chamber for whites...

Here you go, sorry for the large file size if one is on a phone! I'm including pics of the first two beers I made with it. Shortly after these I switched to fermenting in sanke kegs with a thermowell so the temp controller is reading the temp at or near the center of the wort.

 

[Bmd2k1]

reviving thread for a quick check...

Anyone Cold Stabilizing their White kits before racking em for bulk aging? (My sense from re-reading this thread, is that for kits it really isn't needed - but I'm curious all the same.)

Cheers!

 

[winemaker81]

Anyone Cold Stabilizing their White kits before racking em for bulk aging? (My sense from re-reading this thread, is that for kits it really isn't needed - but I'm curious all the same.)

Nope. As you guessed, it's not necessary. Cold stabilization shouldn't be performed if the wine doesn't taste acidic -- it may work, but then it may reduce the TA too much, leaving the wine flabby. As always, don't fix it, if it's not broken.

 

[BarrelMonkey]

Worst case scenario is that you'll get some 'wine diamonds' (tartrate crystals) in your bottles if you chill them for an extended period of time and/or low temperature. They're harmless and sometimes found in commercial wines as well.

The exception is that if you're making sparkling wine you really need to prevent tartrate crystals from forming - they can act as nucleation sites for bubbles and lead to explosive gushing when you open the bottle.

There are also additives which can augment or replace cold stabilization - I have read way too much about these over the past few weeks since I plan to cold stabilize in kegs outdoors this winter and I'm not convinced that our mild Californian winters will be sufficient. (And I'm planning to make sparkling wine...)

The alternatives treatments are essentially polymeric molecules that sequester microcrystals and prevent them from growing:
- Metatartaric acid (MTA) - as the name suggests, derived from tartaric acid; however its effects only last 1-2 yrs depending on storage conditions
- Gum arabic - some kinds seem to have a stabilizing effect in wines that don't need too much stabilization.
- Carboxymethyl cellulose (CMC) - Has good efficacy and longer lasting than MTA.
- Potassium polyaspartate (KPA) - the new kid on the block, only approved for commercial wines in the US in the last few years. I think Enartis is the leading (only?) US supplier, they have a line of products under the brand name 'Zenith'. Could be diffcult to get in quantities that make sense for the home winemaker.