Does anyone know what this is I thought it was lees but I've never seen it look like this before it looks crystalised. View attachment ImageUploadedByHome Brew1492914406.267049.jpgView attachment ImageUploadedByHome Brew1492914423.948126.jpg
Anyone know what this is
- Thread starter Jeremy_84
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
Those are "wine diamonds"- mostly potassium bitartrate. It's excess acid dropping out in the form of crystals, generally from the wine being stored cold or during cold stabilization.
Lots of winemakers will cold stabilize the wine before bottling so they precipitate out in the carboy instead of the bottle.
Lots of winemakers will cold stabilize the wine before bottling so they precipitate out in the carboy instead of the bottle.
IrishBrewer420
Homebrewer / Writer
You say that winemakers can avoid this by "cold stabilizing" the wine prior to bottling. How does one cold stabilize their wine?
jgmillr1
Well-Known Member
First, it is important to understand that the crystals are potassium bitartrate (aka cream of tartar). The primary acid in grapes is tartaric acid, which produces the bitartrate ion. Note that this means that wines made with fruit other than grapes (cherry, cranberry, strawberry, etc...) have a majority of other acids (malic, citric) so are already cold-stable unless you add large amounts of acid blend that contains tartaric acid.
Second, this means that adding potassium containing compounds to (grape) wine will potentially make the wine cold-unstable. So, you need to add your potassium sorbate, potassium metabisulfite, and potassium (bi)carbonate BEFORE you cold stabilize the wine. This way the excess potassium can precipitate out.
Finally, to cold stabilize simply lower the temp of the wine as much as you are able. Wine freezes around 25'F, depending on the alcohol concentration. You want to get colder than you will get in your fridge later. I've even frozen the wine solid in food-grade plastic containers in a chest freezer. For larger batches, I have a chiller that I'll set for 27'F.
Once the wine cools down, you can either leave it for a few weeks and let nature take its place, or you can help it along by stirring in about 1/4 tsp of cream of tartar. These act as seed crystals and will quickly drop the crystals in your container within a couple days.
Let the wine slowly warm up before you rack it off the crystals. Cold wine will easily dissolve oxygen, so it is prone to oxidation when cold.
Second, this means that adding potassium containing compounds to (grape) wine will potentially make the wine cold-unstable. So, you need to add your potassium sorbate, potassium metabisulfite, and potassium (bi)carbonate BEFORE you cold stabilize the wine. This way the excess potassium can precipitate out.
Finally, to cold stabilize simply lower the temp of the wine as much as you are able. Wine freezes around 25'F, depending on the alcohol concentration. You want to get colder than you will get in your fridge later. I've even frozen the wine solid in food-grade plastic containers in a chest freezer. For larger batches, I have a chiller that I'll set for 27'F.
Once the wine cools down, you can either leave it for a few weeks and let nature take its place, or you can help it along by stirring in about 1/4 tsp of cream of tartar. These act as seed crystals and will quickly drop the crystals in your container within a couple days.
Let the wine slowly warm up before you rack it off the crystals. Cold wine will easily dissolve oxygen, so it is prone to oxidation when cold.
