You know how you sometimes go, "Oh, I can finish up that yummy food today!", only to find it spoiled or with fuzz growing on it?
(Ew.)
But that's an obvious sign of food gone bad. What many people don't realize is herbs, spices, and oils all go bad, too. Sometimes, it's obvious—like when a ground spice loses its smell—but other times, it's not—like oil, which can spoil without any visible sign.
How do you keep your things fresh for as long as possible?
There are six major factors involved in freshness: temperature, humidity, air exposure, sunlight exposure, age, and item type.
Pretty much everything does best when stored in air-tight containers, away from sunlight, in low humidity, at a cool temperature (like a root cellar). (If something's prone to bugs, like paprika, it can do better in the fridge, but that's not necessarily necessary—it depends on your climate and storage methods.)
Glass is better than plastic. Metal is best avoided unless you know it won't affect what you're working with.
Speaking of bugs, you know how to check for them, right? Put out a plain white napkin or paper towel. Put a little pile of the herb or spice you want to check on the paper, then leave it for several hours. When you check on it again, 8+ hours later, the pile should be the same. If it's spread out—especially with a little ring around the outside—you have bugs. Ditch it.
That leads us to the age and item type factor.
Let's start with the dried items, like herbs and spices. Dried items start losing their benefits immediately upon grinding, making age a major factor. If you don't know an item's age, try smelling it—as its benefit decreases, the scent will lessen, if it has much of a scent to begin with.
That's why I prefer buying in pieces, to grind myself as needed. (I have a spice grinder with a detachable bowl for easy cleaning.) The dried pieces last longer than either pre-ground or fresh versions of the item.
But if you must or prefer to buy pre-ground items, it's best to limit yourself to buying what you'll use within a year. If you can't—like you'll only use 2 ounces of ginger, but the smallest bag you can get is 4 ounces, or you didn't expect 4 ounces of peppermint to be quite that big a bag—seek someone to share it with. I know others who do this natural remedy stuff, and there are so many forms of it that we pretty much do all different things. We frequently swap ingredient baggies or baby jars of various remedies.
If you think there can't be that much difference between pre-ground ginger that's three years old and fresh-ground ginger from dried ginger pieces, you've obviously never experienced them.
Assuming there are no bugs, nothing's clumping, and you've been using an airtight container, age is a good indicator for a dried item's freshness.
Liquids (oil, alcohol, vinegar, etc.) and butters (cocoa butter, shea butter, etc.) are similar, but have a few quirks. Liquids and butters have definite shelf lives. These can vary from months to years, assuming they don't get overheated and turn rancid, and is dependent on what the item is and how it was produced.
That's a danger in playing with liquids or butters: They can go bad without seeming to be bad. Many liquids will smell or taste off, if they go bad, and some of them will look off—things that you can only identify if you know what they're supposed to look/smell/taste like.
And then there are things like garlic-infused olive oil, which can go bad without perceptible sign, because the garlic hides the signs you would get.
Liquids and butters are best stored in cool, dry, areas, out of sunlight, in tinted or opaque jars. If you're putting them in your own jars, make sure your jars are sterilized and completely dry before you start putting your liquid or butter in it.
Can some things function fine with a bit of water in there? Yeah. All-purpose cleaner and alcohol-base extracts, for example. But as the rule of thumb, use a sanitized, completely dry container. (Dishwashers can be quite nice for easily sanitizing glass jars.)
Assuming nothing reeks, nothing's separated, and you've been using an airtight sanitized-and-dried container out of direct sunlight, age is a good indicator for if a liquid or butter is still useable.
That brings us to items you make yourself. Items you blend yourself should stay fresh for as long as the ingredient with the shortest lifespan—and quite possibly longer. That's because the added ingredients can work to counteract the limited shelf life of the starting ingredients, either from direct action or from chemical changes.
But there isn't an easy way to calculate what blend will last how long. Too many factors are involved. You just have to pay attention and watch it for signs of going bad.
Assuming you use sanitized-and-dried containers and proper storage methods, your shelf life for your homemade items will depend on things like your climate. You'll have to watch your homemade blends or items for signs of them going bad, but they should last at least as long as the ingredient with the shortest lifespan.
Hopefully, this gives you some starting point rules of thumb for figuring out what's good in your cabinet and what needs replacing.
Do you have a story of unexpected herb effect? An opinion on my experiences or recipe? A question on herbs as medicine? Something you want to hear about making? Ask! I'm not the only person I know who does this kitchen remedy stuff, so if I don't know or make that item, someone else I knows probably does.
—M
