How To Ferment Using Cooking Machines

There are very few cooking machines designed specifically to culture or ferment food, and they tend to be extremely expensive and make very small amounts at a time. Here’s how to ferment a large batch of rice using a rice cooker, and of yogurt using a probe crock pot and a thermal jacket.

Rice cookers (not pressure cookers) tend to have a warm function that creates a perfect environment for fermentation.

Cook a batch of rice, following the usual instructions. Unplug the machine and let it cool for a few hours. Now add cool water to cover the rice, and a tiny pinch of salt; then plug it back in. Keep the cooker on the warm function, put the lid on, and leave it overnight. In the morning, the fermented rice is ready to eat, and the liquid is edible as well.

Fermented soy sauce is a great accompaniment, but you can use this rice in any rice recipe as long as you do not overheat it, which kills the microbes. A little table sugar in your secondary recipe can help protect the live cultures as they pass through your stomach. This rice can be kept in the fridge for a few days. Save a little of the fluid to use as a starter for your next batch.

Here’s how to culture yogurt in a slow cooker. It’s a somewhat higher investment. You will need to buy a Hamilton Beach Stay N’ Go slow cooker with the temperature probe, because it allows you to automatically control the temperature when you are custardizing the milk before culturing it. You do not need to stand over the pot, and there is no chance of the temperature getting too high. You will also need to buy an insulated travel bag that was designed for a slightly smaller slow cooker.

Add a gallon of milk, and set the probe function to 180 degrees F. When the milk reaches that temperature, let the cooker go to Warm. It will hold the milk at 180. Let it stay there for at least half an hour. You have now custardized the milk proteins. Turn off the cooker and let the milk cool to 110, periodically checking it with a thermometer or by turning on the probe function briefly.

Now add several tablespoons of plain whole milk yogurt and stir well. Remove the cooker insert from the electric frame, and set the insert with the milk in it directly into the insulated travel bag. Zip it up and set it aside. In 4 hours, check it. The yogurt will be ready to eat at this point, and will have a mild taste. Refrigerate and/or strain to thicken, or drink it warm. To get a yogurt that is more sour, and to get a higher probiotic count, let the yogurt culture more, up to 12 hours but no longer.

With these methods, you can culture food without expensive dedicated culturing vessels or machines. You don’t need a yogurt maker and you don’t need a clay pot shipped from India. What are your slow food hacks?


  1. Black beans or kidney can be cooked overnight in a crockpot. Pour in about 5 cups of beans. Fill crockpot with water. Cook. It’s simple and slick and in the morning you have a crockpot of soft beans to portion into the freezer for refried beans, stewed beans, or any other delicious chili mixture you might concoct.

    Liked by 1 person

    • I love that. Bean and bacon soup is my favorite, and rice and refried beans is big news at my house. I recently learned that the right way to cook refried beans is to add half-and-half. I had some Mexican guys tell me to cook it in oil when I was a teen, and I’ve been trying to make that work ever since. Turns out only the grandmas know what’s really going on, heh. I love getting older. It was so frustrating not knowing anything. Anyhow, I think I’m going to experiment this weekend and see if I can go from hard dried beans to refried beans all in the slow-cooker.


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