Shelf life of spices

Dried herbs really do only last around six months, certainly no longer than a year. They're generally easy to get in small quantities, though.

Spices are trickier. They'll generally last rather longer, but the time will vary. If the spice is used for the colour and/or heat (e.g. turmeric, chilli) it will generally last much, much longer than one used for its smell and/or taste. Whole spices last much, much longer than pre-ground; I generally buy whole spices from asian stores, they sell them in much larger amounts for the same prices as supermarkets; and use a coffee mill to grind the right amount just before cooking (and keep a separate one for coffee!).

If kept in the dark, in a dry, clean, airtight glass container, spices and dried herbs will certainly not become health hazards, and should not pick up unpleasant tastes or odours. The strong-tasting / strong-smelling ones will, however, lose taste and smell, eventually almost completely; since that is the whole point of using them, you might as well not bother once they're off.

And of course (setting aside any actual food safety concerns), you should just trust your nose and palate. If you rub them and smell them and don't get a bright, strong aroma, or taste them and you get flavorless powder, they are dead. If the converse, enjoy!

The answer is different for each spice and grind. Most sources I have seen suggest that 6 months is the long case for 'fresh spices', but all suggest grinding in small quantities so that you will not need for them to last that long.

Following is some information from "Spice Mogul", some basic "Do's and Don'ts"

Do

* Buy spices whole, versus ground, whenever possible.
* Buy in quantities that you will likely use up in 6 months time.
* Mark the date you buy your spices and dried herbs. If there are no dates on the package, take a marker and date each container when opened.
* Grind spices just before using. Grinding releases the volatile compounds that give a spice its flavor and aroma. The longer the spice sits around (either whole or ground), the more the compounds disappear and the flavors lessen.

Don’t

* Store spices and herbs on the counter or close to the stove. Remember that just like with oils, heat, light, and moisture are enemies of a spices flavor and shelf life. Cool, dry and dark should be your watch words.
* Forget to check for freshness.
* Use pre-ground spices if you can avoid it. If you must, test for flavor by rolling a small amount between your fingers and taking a whiff. If it releases a distinct aroma, you’re ok. If you have to strain to smell it, pitch it and buy fresh. There is no sense in ruining a dish full of other ingredients because your spices are not up to their full strength.

Spice Mogul also has a good collection of specific advice that you may wish to review.

Be aware that even if the aroma and flavor of a dried spice is retained after being ground, there are many ground/powdered spices (and many fresh undried spice/herbs) that lose all their flavor when cooked/heated.

One of the worst dried ground spices for losing all flavor when cooked is dried powdered fennel seed. Even when it's recently ground/powdered, it will lose all of its flavor when heated. In the case of fennel, if you don't want to use whole fennel seed, then only slightly crush the seed. Do not grind it into a powder if you are going to cook with it.