And why does Sriracha turn brown over time?
It's no secret that Sriracha can make any savory breakfast better, from scrambled eggs and breakfast burritos, even bloody marys. And even if you tend to store hot sauce in the fridge, there's no reason to freak out about food safety if you leave a bottle of Sriracha unrefrigerated overnight. In fact, you shouldn't even worry about the safety or quality of the bottles of Sriracha sitting at room temperature on restaurant tables for who-knows-how-long. That's because Sriracha doesn't' have to be refrigerated, even after the bottles have been opened.
"No, they do not have to be refrigerated," explain the folks at Huy Fong Foods Inc., the company that created and still manufactures Sriracha in Irwindale, CA. The best way to store bottles of Sriracha, according to the manufacturer? "Just make sure they are stored in a cool, dry place."
The reason you don't have to refrigerate Sriracha is because its ingredients are pretty resistant to bacterial growth, which is what causes food to become unsafe and ultimately spoil. Chili peppers, for instance, have been studied for their antimicrobial properties, meaning that it can inhibit the growth of nasty microorganisms. Distilled vinegar, another main ingredient in Sriracha, is also pretty good at preventing the growth of food-borne bacteria, including E.coli.
But even if you don't have to worry about getting sick from Sriracha that's been unrefrigerated for months, that doesn't mean your Sriracha will taste—or look—exactly the same as it when when you first opened the bottle up. Even though Sriracha won't ever really spoil, every bottle of Sriracha comes with a best before date, "lasered on towards the neck of the bottle. You can feel it with your fingers," write the manufacturers on their website. Chili peppers also change color over time; that's why older Sriracha sometimes looks brown.
If you want to make sure your Sriracha stays as vibrant red as possible, you can keep it in the fridge. But it won't keep your Sriracha from going bad. The vinegar and chilis are already doing that for you.