Is the expression ‘playing cat and mouse’? No, is it ‘sailing close to the edge’? Yes. I often leave my new batches of kefir out of the fridge for as long as I gamble that I can, before separation into curds and whey occurs. This time I just forgot to put the batch into the fridge before bedtime. There is so much punch in the grains that I transfer from the previous batch into the new milk, that, if the weather is warm, it gets cracking and ferments up fast as!