I've finally made my 1st SCD legal yogurt batch without using any yogurt makers. Just wrapped jars in towels and put them on top of my fridge. I've used some additional small jars with hot water to keep the temperature up, but a hot water bottle can also be used if you have it.
I've changed the typical recipe a bit by adding more double cream to the whole milk - 50/50, and the end product was creamy and delicious, only a bit tart. The more it stayed in the fridge after 24 hours incubation the better it became.
I'm onto my 2nd batch now, trying to use a bit of the 1st yogurt as a starter.