DIY Yogurt

I've been making yoghurt for just over two years now using a yoghurt maker similar to the one from Lakeland. If you're using fresh milk, heat it to 86°C then let it cool to 45°C, mix in 1-2 tbsp of yoghurt (per litre of milk), mix well and hold at 45°C until it's done (usually takes 4 hours or so if your starter yoghurt is very biologically active, 8+ hours if not). After that it goes in to the fridge overnight and is strained for about 1 hour to thicken it up a bit. The benefit of UHT is that it's already sterile enough to use without heating to 86°C, but the texture may end up different to yoghurt made with fresh milk.

I usually use freeze dried sachets from Amazon as a starter instead of supermarket yoghurt, as I want specific strains of bacteria, but once you've made a batch you can just use the homemade yoghurt as a starter instead. Only very recently I had to re-start from a sachet as my homemade stuff got some sort of contamination and started going fizzy!