Speaker 1: Welcome to brain stuff from how stuff works. Hey, I'm
Speaker 1: Christian Seger, and this is brain stuff. You know when
Speaker 1: you reach inside the fridge and your loaf of bread
Speaker 1: has turned green and it's covered with white wisps of mold,
Speaker 1: or when your tomatoes look like a deflated balloon and
Speaker 1: they have spores growing out the top. It's even worse
Speaker 1: when those spores start turning black and wrinkly and they
Speaker 1: bore into your food and spread out their fungal roots. Obviously,
Speaker 1: we're all disgusted by this kind of imagery, as if
Speaker 1: we've got some kind of natural revulsion despoiled food, and
Speaker 1: we all scream that's gross and probably dangerous. Do not
Speaker 1: put it in your mouth. Well, luckily we have refrigerators
Speaker 1: which slow the growth of bacteria on our food. Freezers
Speaker 1: will do you one better by stopping bacteria completely by
Speaker 1: freezing them solid. But we can't freeze everything. Some foods,
Speaker 1: like let us, milk or eggs are less than appetizing
Speaker 1: after you freeze them, And imagined trying to thaw orange
Speaker 1: juice every morning. There's got to be some middle ground
Speaker 1: between freezing your food rock solid and leaving it out
Speaker 1: to rot. So what's the best temperature to set the
Speaker 1: inside of your fridge at? Well, before I answer that,
Speaker 1: let's understand spoilage a little bit better. Basically, microscopic organisms
Speaker 1: are constantly feasting on our unattended food items. Spoilage bacteria
Speaker 1: are fast and inevitable. They're constantly consuming tiny portions of
Speaker 1: our food and then spreading their waste all over it.
Speaker 1: M M. That's what makes rotten food smell foul and
Speaker 1: appear spoiled. And bacteria multiply, sometimes rapidly. As long as
Speaker 1: nutrition and water are present, bacteria be making babies. While
Speaker 1: there are many methods to detect bacteria, most take several
Speaker 1: hours unless you've got an infrared light handy to trace
Speaker 1: their biochemical footprints. Even if you can find them, not
Speaker 1: all bacteria are necessarily bad. For instance, a certain degree
Speaker 1: of bacteria are necessary to prevent illness. Others are used
Speaker 1: by food manufacturers to enhance the taste or texture of
Speaker 1: their products. Bacteria in beer can control its calorie content.
Speaker 1: The holes in Swiss cheese occur when bacteria use lactic
Speaker 1: acid to produce bubbles of carbon dioxide gas that leave
Speaker 1: holes behind. And of course, there's yogurt that stuff has
Speaker 1: bacteria a plenty, containing probiotic enzymes that produce vitamins, enhanced digestion,
Speaker 1: and aid our absorption of nutrients. But for the most part,
Speaker 1: visible bacteria and mold is a sign that food is
Speaker 1: not suitable to eat. Some can even be lethal, like salmonella, E.
Speaker 1: Coli and listeria. So what's our best solution? Using our
Speaker 1: cold refrigerators to slow bacteria's growth without also freezing our food.
Speaker 1: The US Food and Drug Administration recommends that you keep
Speaker 1: your refrigerator at or below forty degrees fahrenheit or four
Speaker 1: degrees celsius. Anything higher and the food will spoil too quickly.
Speaker 1: For the food that you can freeze, you'll want the
Speaker 1: temperature to be zero degrees fahrenheit or negative eighteen degrees celsius.
Speaker 1: Check both of these periodically with a digital appliance thermometer.
Speaker 1: And you want another tip, don't jam your fridge full
Speaker 1: of stuff. This prevents the proper air circulation needed and
Speaker 1: can hasten spoilage in the freezer. However, feel free to
Speaker 1: fill her up. A full freezer actually cools more efficiently.
Speaker 1: Check out the Brainstuff channel on YouTube and for more
Speaker 1: on this and thousands of other topics. Visit how stuff
Speaker 1: works dot com.