An experiment in cold-soak maceration..

[JohnT]

Here's a more in-depth explanation... way over my head

Yes, but unless I am mistaken, that does not seem to explain why temperature is an issue.

 

[LonelyMassachusetts]

This is really weird. I'm surprised as everyone else. For my batch of blueberry, I used a bit less than 18 pounds for five gallons. I didn't use cold soak maceration and it has a beautiful color right now.

It's too bad the cold soak maceration is so light colored, but kudos for the experiment!

 

[botigol]

I have been trying to find the article that I, at least relatively recently, read about this, but haven't come across it today. The point that I recall was that cold maceration with Pinot Noit grapes only led to increased color extraction up to a certain point and after that the must would actually lose color. I have a hard time believing that four days would be sufficient to cause this since it seems like the article was indicating an extended period of time, but it is an example of this type of situation and maybe blueberries have more or less of whatever it is that causes the lightening that could shorten the timeframe. I may try looking for that article again later.

 

[bein_bein]

Here's one of the articles from which I based my experiment/times.

http://www.brsquared.org/wine/Articles/coldsoak.htm

Another article I found seems to lend credence to the theory I posted earlier and one possible solution that was suggested was adding tannin....

Why do it? Some winemakers like the added color and flavor and feel that it improves a wine’s overall mouthfeel and that it might even improve the ageability of the wine. Sometimes, more color can be extracted during post-fermentation extended maceration as a result of the increased solubility of color-containing molecules from the skins in the presence of alcohol. Another factor in extended maceration is that short chain tannin molecules can link up to form longer chain molecules that yield more supple and pleasurable wines.​

However, just as with pre-fermentation cold soaking, with extended maceration, experience is the rule to follow. Empirical studies show that extended maceration can make wines that are more complex and delicious, but sometimes if taken to extreme can result in overly astringent and harsh tannins, which may not benefit from aging in barrel or bottle. This process is often done with Bordeaux and Rhône grape varieties that have significant tannin levels. However, there is typically some loss of fruitiness and color in the process, but many feel it is justified by the complexity and mouthfeel that it adds to the wine.​

Very interesting... maybe this year I'll have to do a number of smaller batches with incremental cold-soak times, and varied tannin levels....first I'll have to devise a way to keep everything organized ..lol


p.s. Here's a link to the article that was quoted here