“by forming sulfonates with many of the oxidized forms of the developing agents, sodium sulfite decreased the concentration of the oxidized form to such a low value that the initial rate of development is not materially influenced by the oxidized forms. sodium sulfite thus acts to stabilize and maintain a uniform developing action by the developing agent.” haist

Folkways occur as knowledge grows. Best practices do enter the studio from commerce. Kodak and its competitors knew much that didn’t make it to the field of practical studios, however, they also learned from the enthusiast. Oxidized developer is brown. If your developer turns brown as you mix it, your water is too oxygenated. Stir less. Do the pinch thing. Stir from the bottom of the mixing jug. Also, try boiling the water, then letting stand a half-hour before using. Don’t use water from an “aerator” spout, such as those in many kitchen sinks. The boiled water thing works, sometimes; was a DuPont trick.

Do we add a pinch of sulfite before mixing the metol into a developer; why?

Yes, it was taught by Kodak field reps along with the renowned Kodak chemist George Eaton.

Gorge T. Eaton · 1986 · 
Developer and other processing - solution formulas are published with the chemicals listed in the order in which ... In mixing developers , a pinch or two of the sodium sulfite is added to the water before adding the developing agent


3. Always dissolve the preservative before the reducing agent which it has to protect . Exception ( see page 82 ) : developers containing Elon . Elon should be dissolved in water containing a pinch of sulfite , balance of sulfite added ...

Camera Magazine - Volume 75 - Page 71

1952 · ‎
Add some sulfite to retard spoiling ( oxidation ) and step up development ( reduction ) . Expose a roll of fast pan film at 500 Weston ... He starts his mix by taking a pinch of the sulfite and dissolving this first in the water .

Developing: The Technique of the Negative - Page 87

Kurt Jacobsohn · 1948 · ‎
Many practical workers prefer to dissolve a pinch of sulfite , or a crystal or two of metabisulfite , in the water before dissolving ... as it is insufficient to upset the balance between sulfite and alkali in the finished developer .

Minicam Photography - Volume 6, Issues 1-6 - Page 75

1942 · ‎
A pinch of sulfite added before the metol , will reduce the chances of your developer oxidizing while it is still being mixed . A properly mixed developer should show little evidence of discoloration . If your dark - room illumination ...