Reaction when adding PMS

[GeoffMcG]

I'm making a batch of Rose. Primary fermentation was in late March. I have two carboys full, one 10 litre and one 23 litre. The wine in both containers have been treated identically.
Today I added PMS to get 30 ppm so2. When I added to the 10L there was not reaction but when I added to the 23L carboy there was lots of fizzing and foaming for about 15 seconds.
Any idea what caused the different reactions with two containers of wine that I thought would be identical?

 

[Rice_Guy]

The effect you saw is “nucleation” of CO2 on the rough surface of the metabisulphite. You could generate foaming with other crystalline materials as salt or sugar. Essentially it only means that there is more residual CO2 in the larger container/ or it takes more work to get the gas out of the larger container.

there was not reaction but when I added to the 23L carboy there was lots of fizzing and foaming for about 15 seconds. , , Any idea what caused the different reactions with two containers of wine

 

[GeoffMcG]

The effect you saw is “nucleation” of CO2 on the rough surface of the metabisulphite. You could generate foaming with other crystalline materials as salt or sugar. Essentially it only means that there is more residual CO2 in the larger container/ or it takes more work to get the gas out of the larger container.

Thanks for that info. I suspected it may have something to do with CO2. I tasted both wines before addition and noted the 'sparkle' in the larger container.
Cheers