But how has mustard become the staple condiment it is today? Evidence of mustard cultivation dates back to the Mycenaeans in Greece, and in 42 BC, a Roman agricultural writer named Columella even included a recipe for mustard in his book,De re rustica. Arguably, humans have been cultivating and eating mustard since the beginning of modern civilization.
This honey-mustard chicken recipe gets not one, but two kinds of mustard in the glaze.
Why the confusion about the best way to store mustard? Don’t all perishable foods go bad?
First off, let’s consider what it actually means when food “goes bad.” Speaking to David Zilber, chef, food scientist, and author ofThe Noma Guide to Fermentation, I learned that “when we talk about food going ‘bad’, it’s usually the food’s inevitable transformation at the hands of microbes in the environment.” Fortunately, there are ways to slow this transformation down, and mustard happens to be a great example of this. “Mustard is made of just a handful of ingredients,” Zilber says. “But the ingredients itismade from are by themselves all pretty resistant to spoilage.”
Dr. Julia Skinner, fermentation educator and author ofOur Fermented Lives, backs this up: “The more acidic or salty your mustard, the longer it will last.” This is because both vinegar and salt are used in fermentation, and “fermentation creates a selective environment that inhibits the growth of harmful microbes, by allowing our microbial collaborators (like acetic acid) to flourish” says Skinner.
And according to Brandon Collins, mustard sommelier for Maille (yes, it’s a real job), mustard has one last ace in the hole. Even before the salt and vinegar are added, mustard seeds themselves are anti-bacterial. But, like many shelf-stable foods, that jar of mustard “should still be kept in the fridge after opening to prolong the complexity, heat, and flavor.” Collins also notes that “as mustard sits and is opened and closed and taken in and out of the fridge, the flavor will change…so while it doesn’t go bad like a fish or wine, it does become less exciting.”
So ultimately,doesmustard go bad? “No,” says Zilber, “you don’t have to throw it out on the day of its best before date. It’s not like at 12:01 on New Year’s Day that mustard spontaneously transforms into rat poison.” But considering my collection, the answer I really wanted was, can I keep eating the mustard that’s been sitting at the back of my fridge for a year? Two? Ten?! “Yes, yes, and yes,” says Collins. Though it won’t taste as fresh as the day you opened it, “there is no concern from a ‘getting sick’ standpoint, but if you have mustard in your refrigerator for more than a year, I suggest throwing it away and purchasing a smaller container next time.”
