Invest in a thermometer. You can use a simple food thermometer that can read temps up to 100C, or use a 'contactless' IR thermometer. I have found that I get accurate readings using my inexpensive IR thermometer. Just make sure you are aiming the IR beam into the water, and not on the side of the pot.
I use a French press, with recommended water temp of 90.5 - 96.1 C. I simply boil the water, turn off the heat, then wait 30 seconds before pouring.
I'm in the U.S. and have never heard the term 'bog standard', but from Google I learn that it is just an ordinary kettle.
If you really want better temp control, invest in a good electric kettle with temperature control and readout. They're not really so expensive on Amazon; Maybe around $50 USD, which converts to about £38. I have been considering purchasing one myself, but I need to find my favorite coffee bean first.
Ultrarunner
