The hardest part is sterilising the eight jars/pots, their lids, the big pyrex bowl, the ladle, the table spoon and the 1/2 litre measuring jug I use for putting the nascent yogurt into the jars. I'm not sure how strictly necessarily this palaver is, as "Super Gut" doesn't really mention it (that I can remember), but I don't fancy the idea of lacto-fermenting random bacteria hanging about the kitchen.