Then again, there is also an awful lot of hydrogen ions in the plasma, so maybe it would be a combination of salt and sour.
Sourness (acidity) is a property of water based solutions. Protons are never free in a solution, because they are always bonded with water in the form of hydroxonium ions (H3O+), and this is what pH measures, and is what makes a solution acidic.
If the hydrogen stays as a plasma, the protons won't bond with water and won't turn it acidic, and it won't be sour.
If the hydrogen cools enough to bond with the water, the electrons will mop up the protons quicker than the protons can form hydroxonium, and it won't be sour.
At least that's how I see it.
