The RSC suggest that the best drinking temperature is 60-65C and that denaturing occurs above about 75C. If your milk is at 5C, then a >60C cup of tea can only be achieved from a <75C brew if you add less than about 13% milk.
I have no idea what proportion of milk I use, or what temperature I prefer to drink it at, so I suppose I should really measure both to find out…
I have found that I can’t discern any difference between MIL and MIF with semi-skimmed milk, but full fat milk produces a nasty-looking film with MIL.
Sounds like you have some kind of gross-ass European mucus milk. Or maybe some problem with your water. Are you… are you just dipping buckets into the Thames?
When I lived in Britain, it was explained to me that the custom of putting milk in the cup first had to do with the upper class having delicate bone china (in reality, bone china is more rugged than it looks) and not wanting the shock of the hot tea to crack the teacup. Milk first meant the temperature dropped down to a safe level.
Except, as I mentioned, bone china isn’t delicate at all. But that was the story, FWIW.
I have heard just the opposite (the sign of a good story is that it also exists as its own antistory).
Milk first is a middle class thing because the shock of boiling tea can crack a stoneware cup, whereas bone china can stand it, so MIL is U, MIF is non-U.
If you’re a British social climber, you’re probably a MILF (milk-in-last fan).
The teapot seldom had time to cool down in our house when I was a kid, so I learned the true and proper way to make tea at an early age. My parents, both of solidly middle class Brit stock, always insisted on milk first. Also, always warm the teapot before adding the tea.
My grandfather came to Canada from England as a young man. When we visited him on his farm in Manitoba, I was fascinated to see him pour his tea into his saucer and drink it from there.