Heat up Yogurt

yogurt

Considering the heat wave, I've been thinking – most instructions for Yogurt making say to take starter culture, put it in milk, put the milk in a warm pot (or a yogurt maker) for several hours and you've got yogurt.

But it's fairly hot now, with outside air temperatures in the 90s (F). What would happen if I just mix starter and milk and leave it out? Is there danger of spoilage?

Best Answer

You get better / more consistent results if you keep a constant temperature. 'The Art of Fermentation' says

to make nice thick yogurt you must incubate it, maintaining it in a temperature range between 110° and 115°F/43° and 46°C.

By leaving your yogurt outside you're exposing it to temperature variations, which can get too low (perhaps not hot enough for proper fermentation, or you'll need more time and won't be thick enough, and possibly just enough for harmful bacteria to "win" the battle agains the yogurt starter) or too hot (which could curdle).

You'll have no control of how much time you need for your yogurt to be ready.