By Bonnie S. Benwick
Washington Post Staff Writer
Wednesday, May 12, 2004; Page F01

There's a tall, dark and sturdy bottle of Worcestershire sauce on the go-to shelf in my kitchen cabinet. It was procured by my late father-in-law, who, being a child of the Depression, thrilled to the bounty of warehouse shopping, and seldom failed to buy lots more than we needed to run the home we used to share.

On my watch, this 15-ounce bottle has been packed and unpacked in a mover's box and dashed from at least once a week for the past two years. Yet it remains more than half full. It's had a good life; it shows no sign of age, literally. And that's the problem. I can't tell how old it is.

I bet I'm not the only one hoarding such vaguely troublesome bottles, boxes and packets. Aren't such items meant to be stored for a long time? Old is not necessarily bad if you're talking about sea salt and grenadine, right?

We tend to hang on to certain foodstuffs for motives beyond the palatable. Maybe it's a bottle of barbecue sauce from that great weekend in Waco, or a package of blue cornmeal that you won't use again till your gourmet club regroups. Perhaps putting your provisions in order is rock-bottom on your list of priorities. Or you're a little lazy.

No one's judging here.

We also let things linger on the shelf because their label information is confounding. Some pantry products have easily readable freshness dates (see accompanying box), but many of them don't. The federal government requires freshness dates on baby formula and baby foods and mandates their removal from store shelves once they're overdue. But "born-on" or "use-by" stamps are not required for the spices, condiments, mixes, baking chocolates, etc., currently manufactured or packaged in the United States.

Product date codes are harder to find -- embossed or stamped in small letters -- and are not standardized among different manufacturers. While code dating is helpful for suppliers and retailers, it makes consumers like you and me work a little harder to figure out product shelf life.

And we shouldn't have to work harder. If you agree, let manufacturers know how you feel about such detective work.

The package markings are in the form of number and/or letter codes. The numbers in the codes are based on so-called Julian dating (that is, each day is numbered starting with 1 on Jan. 1, so 365 designates Dec. 31) and the letters A-M represent the months of the year (sometimes omitting the letters I or J), so A would be January and M would be December. The remaining letters and numbers in the code refer to the specifics of manufacturing (batches, work shifts, plant numbers).

You're ahead of the game if you had already noticed the codes, but one size does not fit all: For example, the K807A on Betty Crocker Parlor Perfect Sprinkles means that they were manufactured in K, the 10th month, of the year that ends in 8, on the seventh day of the month (Oct. 7, 1998). The B4HN01 stamped on the Old El Paso Mild Taco Seasoning Mix (shelf life: two years) means B (February) 2004 (the rest of the code is specific to the manufacturer).

Even then, the code for your bottle of vanilla extract can be stamped on the box and not on the bottle itself. If you're like me, you toss such boxes every time you scan an issue of Real Simple magazine, inadvertently creating more confusion in your life. Ach.

Let's say you've cracked the code on your Tabasco sauce. That information is less edifying if you've stored the bottle improperly. Food experts agree that proper storage is what matters most, in terms of shelf life.

Time, temperature, light and air: According to a preparedness-resource business in Utah called Emergency Essentials, the shelf life of most foods is severely abbreviated by these factors. If you've stored some food items in a garage that heats to 100 degrees in the summer, for example, you should expect a shelf life of less than half of what could be obtained at 70 degrees. And while the innards of a dark glass jar might be more difficult to fathom, there's a good chance they'll last longer than if they were encased in clear glass.

You'd be hard-pressed to find a manufacturer who will tell you that their staple products become unuseable beyond the suggested lifespan, though. Instead, they speak of quality issues, of color and taste being off, of consistency and performance that might be compromised. Fair warning, but this system may prompt you to replace the item before you need to, or you let the item just sit and sit on your shelf.

Which brings us back to the heart of the matter: You've kept too many things on your shelves for far too long. Here are some rules of thumb for various foods:

SPICES This category includes especially egregious examples of a shelf life gone bad.

• Spices are best used within three months to one year of purchase, according to folks who make them and researchers who test them. Over-the-hill, pre-ground and powdered spices retain their basic color and smell, as you can attest; that's why you keep them around. A half-teaspoon of dried herbs past their prime won't ruin a recipe, but it's akin to adding the visual without the audio.

My pal Rhonda surrendered to me her 25-year-old, 1.5-ounce tin of Kroger paprika (hey, how fast do any of us blow through paprika?), which came to Washington with her from her college days in Arkansas. It's older than her children. If you can think back to the decade you bought it, do you really need me to tell you to pitch it?

• Nutmeg, cloves, cinnamon, allspice and peppercorns kept whole are among the notable exceptions to this rule and are supposed to remain "best" for 24 months.

• Varieties of dried chili peppers, which are usually sold whole in cellophane and hard-plastic, see-through boxes, are said to have an "indefinite" shelf life. But a spokesman for Coosemans Worldwide, an international consortium of growers, shippers, brokers and importers, says such foods may start to lose their flavor after six months. More sell-by dates are appearing on their products these days, though. Take heart.

• I'll sneak salt into this section since it's often a spice jar's next-door neighbor. Salt is a mineral, and its shelf life is also listed as indefinite. But the folks at Morton Salt suggest replacing your carton of their Iodized Table Salt after 42 months, because the iodide therein may volatize, or vaporize, after that time. The salt itself remains stable.