When mixing the formula from scratch its probably a good idea to boil the
water first to drive off dissolved air to reduce the amount of oxidation of the
metal.
I never had a problem if I first added at little bit of sulphite to the water
before adding the Metol. I don’t remember how much. Maybe a teaspoon or so. The
sulphite was supposed to prevent oxidation. The resulting Metol solution would
have no discernible tint. The rest of the sulphite could then be added.
