I just did my acid adjustment and first SO2 addition to this year's wine, and I'm wondering about the resulting gas release.
I can understand why adding tartaric to a low-acid wine would result in a big release of CO2, enough to overflow the carboys. But there's a lesser bubbling with the addition of just a quarter teaspoon of K-meta. What's the chemical basis of this? Is it SO2 gas being released?