Does Mustard Go Bad? And, How to Tell if It’s Expired

Mustard is a common household staple that seems to live on shelves indefinitely. Just how long can you use it after its best-by date?

It’s evening and you’ve just finished making dinner. You’re setting the table with your finest plates, silverware, hand-blown wine glasses, and serving bowls which are spread out across the tablecloth. As you go to grab the sauces and the mustard, you notice your trusty jar expired the month prior. Do you toss it out? Is it safe to consume? And on that note, does mustard go bad — does it ever really go bad?

In short, yes. No food item will last forever. Knowing how to tell if your mustard has expired is another matter, especially if the best-by date has smudged off of the label. So it’s always a good idea to follow expiration dates as closely as possible, though for vinegar-based foods like mustard there will be some leniency. How much time after the best-by date it’s good for depends on the type of mustard, how it was stored, and how long it’s been open.

Fair warning, don’t eat expired mustard if the taste or consistency seems irregular. It’s not necessarily a dangerous undertaking to eat mustard past the best-by date, but at some point, it can become unsafe for consumption. (Besides, it won’t do your tastebuds and digestion any favors!)

Below is a practical breakdown of the shelf life of mustard and tips for how to navigate the sometimes gray areas of food expiration.

What’s In Mustard?

At its most basic level, mustard is made with a combination of dried mustard seeds, salt, water, and another liquid such as vinegar, white wine, lemon juice, or even beer. As for the mustard seeds themselves, they come from a plant in the Brassica family with pretty yellow flowers. White, brown, and black mustard seeds are all used in the culinary world, with the white and brown seeds the most common for making the paste we all know and love called mustard.

Human innovation forever looking to evolve has resulted in some seriously diverse types of mustard, from your classic yellow mustard (a staple of American grill-outs) to earthier, spicy brown mustards with only partially ground seeds and a distinct texture. If you have a food processor and a few simple ingredients, you can even make mustard at home.

The Shelf Life of Mustards by Type

There are quite a few types of mustard — yellow, dijon, brown (or, deli-style), whole grain, French, honey, and several others. There are also mustard seeds themselves as well as the powder made from grinding those seeds up, which you may already have on your spice rack for cooking. The seeds and powder, both dry, won’t need to be refrigerated but do have an expiration date just like the jars and squeeze bottles of wet mustard.

The basic ingredients for each type of mustard will be the same, though their shelf lives will have some variation. This also depends on how they’ve been stored. For the sake of simplicity, we’ll assume your mustard is either unopened and in the pantry, or has been opened and is safely stowed in the refrigerator. In both scenarios, while it may be obvious, the mustard should have been properly closed and sealed.

So does mustard go bad? Here’s a quick cheat sheet for the shelf life of mustard past the best-by date:

• Yellow Mustard – Good for 1-2 years unopened; good for 1 year opened and in the refrigerator.
• Dijon and Brown Mustards – Good for 2-3 years unopened; good for 1 year opened and in the refrigerator.
• Honey Mustard – Good for 2-3 years unopened; good for 1-2 years opened and in the refrigerator.
• Dry Mustard – Good for 1-2 years in the pantry.

Note that this is only an estimate and refers only to products purchased in a store, not to homemade recipes! Always inspect your mustard before serving it as a condiment or using it in a dish.

How to Tell When Your Mustard Is Bad

Because of mustard’s relative simplicity, despite the many types and nuanced recipes, it can actually be pretty easy to tell when it has expired. The vinegar keeps it shelf-stable past expiration, as mentioned above, though taste can diminish in potency over time.

Here are a few things to look out for when trying to tell if your mustard has expired:

• Mold – If mold is growing in your mustard, along the surface or around the lid, toss it. Mold spores spread quickly and even removing the affected areas won’t completely remove the bacteria and make the mustard safe to eat.
• Aroma – If your mustard smells sour or rotten, there’s likely some bacteria growth and it should be discarded.
• Color – Slight changes in color happen over time, but your mustard is no good if it’s turned a darker greenish-brown or a really pale, almost sickly yellow.
• Texture – A runny or chunky texture that doesn’t mix well is another sign of expired mustard. A little drying along the surface or around the lid is natural, however.
• Taste – A burning, bitter, or especially acidic taste indicates your mustard no longer cuts the mustard. An unpleasant taste will also usually accompany other signs of expiration, such as a sour smell.

Final Thoughts

So does mustard expire? Yes! But you may have more time on your hands after the best-by or expiration date than you realize. Mustard from 2002 should be tossed no question, but last year? Use the tips above to make sure you’re in the clear.

Looking for more practical kitchen tips like how to make flour last longer? Explore our blog for more lifestyle guides, recipe ideas, and how-tos for making each day a little more worry-free and eco-friendly.