I have a carboy of merlot and 1 of syrah that has a tiny ribbon of yellow around the neck right at the top of the wine.The wine has pretty much finished working,smells fine, etc. I'm not sure if it is sediment thats being carried to the top with CO2 , or a bacteria starting to bloom.I'm thinking I should rack and sulfite to 30 ppm, but would appreciate another perspective.Thanks
If it's finished with fermentation and ML you should definitely get the free SO2 up. How high depends on the pH of the wine, but I'd bet that 30 ppm isn't enough. Merlot doesn't usually have pH as low as 3.30. My guess would be 3.50 or higher.
Take the 2 decimals to the right of the pH and set the free SO2 to that number in ppm. IOW, if the wine's pH is 3.50, set the free SO2 to 50 ppm.
Tom S
Yellow sounds odd; if it looks white it could be mycoderma.
If it's forming a film get rid of it; I would put my thumb over the air-hole in a wine thief and slowly insert it with the goal of overflowing the carboy and washing the film away. Then I would sulfite as Tom suggested. It can't be something that should be there as I see it, try to get rid of it.
Here is an article on mycoderma, but again I have never seen anything yellow grow on my wines.
Joe
Joe
It's probably residue from some foam that was there during fermentation. I get rings all the time around the carboy neck, especially right after secondary fermentation. If it smells good, that's probably what it is. As TOm suggested, make sure your free SO2 levels are up if MLF is done. I don't think you have any thing to worry about.
Bob
DrinksForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.