This is a follow-up to the thread You CANNOT make decent lather with six teaspoons of water .... Since we have a discussion on how much is too much, I wondered what is the bare minimum of water - and cream too. So I did this test. I think I've eliminated all the variables and given all the details, so anyone having trouble lathering should be able to repeat this method and get a similar result. Or at least use it as a reference/starting point.
Executive summary: 1/4 teaspoon of cream + 3 teaspoons water + dry shaving brush = sensible lather.
The test gear. Omega 31064 boar brush; Proraso green tube shaving cream; distilled water (honestly!); measuring spoons; plastic mug; mixing bowl.
The method. Brush had been drying for 3 days. Measured 1/4 teaspoon of shaving cream and put it in bowl. Measured 4 teaspoons of distilled water into plastic mug. Warmed water in 900W microwave for 5 seconds - went from 68°F to 93°F - hardly worth doing, but here for reference. Placed brush in plastic mug of 4tsp water to soak for 5 minutes 30s.
Building the lather. Gently squeezed brush over the mug. Started mixing in the bowl. When well mixed but too dry, dipped brush in mug and continued mixing. I dipped the brush in the mug 6 times in all.
The result. Just enough lather to fill the brush. Nothing excessive, but enough for a 3 or 4 pass shave I think. There was 1 teaspoon of water left over in the mug. This could be used for dipping the brush between passes if necessary.
It's worth noting that these aren't my best performing items. If I had used my badger brushes and TOBS cream, I would expect twice as much lather or more. But I thought my Omega brush and Proraso cream would be owned by more people so the test is more relevant to them this way.
I hope this will be of use.