So now I freeze the yeast in loaf-sized portions and just take it out as I need it. Here's how.
Crumble the yeast into a bowl and add about twice as much flour. It's not critical how much flour, but it helps to make it up to a convenient multiple of loaves. In this case I've made it up to 350g, so each one will be about 35g.
Rub the yeast into the flour as if you were making pastry. You should have a fine homogenous mixture with no lumps.
The idea is to coat all the particles of yeast with flour so they they don't stick together and will thaw very quickly.
Put a piece of cling film onto your scales and weigh out 35g of your mixture. Twist into a ball the size of a golf-ball. Keep it nice and loose so that it crumbles easily when you come to use it.
Tadaaaa! Perfect results every time!