Here’s my experience and practice. Very similar to
@Brian55 - I carboy bulk age for a minimum of 12 months with no racking. Wines going into the carboy get a one time dose of 1/2 tsp of Kmeta (suggested is 1/4 tsp every racking). When the wine goes into a barrel, I have been adding another 1/2 tsp of kmeta. Now that I have the ability to check the SO2 levels, that might change. I barrel age for a minimum of 6 months. My larger barrels get a minimum of 12 months. I do not add kmeta at bottling.
My winemaking journey has led me to the “less is more” adage. I don’t use bentonite, sorbate, or clearing agents. I’m learning how to more closely monitor my use of Kmeta. I simply want to less chemicals replaced with more time. Winemaking is teaching this impatient person how to be patient.
I’ll be performing a SO2 comparative test in the coming weeks. I’ll be bottling 150 bottles on or around May 1. I’ll test the SO2 levels of the wine going from the barrels to bottles and the replacement wine from the carboys into the barrels. I’ll also check the levels of a bottled wine that has been aging in bottles for six months and twelve months. And, I’ll compare all this to commercial wine. The point of the test is to ultimately use less kmeta. I’ll post the results on a new thread.