Why do we like sudsing up our dishwater when doing dishes?
The obvious reason is that we think that the suds somehow contribute to the cleaning power.
This is not true, but there’s a reason why we think that. Before synthetic (sulphonated) detergents were invented, we used soaps to clean dishes.
The trouble with soaps is that calcium and magnesium in water would combine with them and render them ineffective, and the harder the water (higher mineral content) the bigger a problem it was.
The upshot was that the Ca and Mg would stop the soap foaming, so you had to use enough soap to the water to use up all the Ca and Mg, and have enough left over to do cleaning. So the lather test was to see if there was left over soap – if it didn’t make suds, then you didn’t have enough so you had to add more soap.
Synthetic detergents completely avoid this problem, because they don’t bind to the Ca and Mg, but we have been conditioned to associate Ca and Mg with cleaning ability.
Actually, truth be told, suds actually get in the way. Detergent that is sitting out of the water in suds would be better used in the water cleaning dishes. The other problem of course is that you have to rinse the suds off the dishes before you dry them.
So here’s how to wash. Fill the sink with dishes and water, and add the detergent LAST. When you add it, gently swirl it around so that it mixes, but don’t lather it.
Let the dishes soak for half an hour or so, so thatthe detergent molecules can go to work, and Bob’s your uncle.
Any persistent grime can then be removed with soda ash.