If fully composted it won't go "bad"...but you'll lose some of it's nutrient effects as it continuously ages, especially N content. As noted, it will also shrink in volume over time as it settles, loses some moisture, and loses some of it's structural stability. That said, it's effect on mineral soil as an addition is one of it's strongest qualities, anyway. Though some that rely on composting as an important part of their nutrient regiment might lament the loss of it's overall strength, I find the most value of compost in what it does to soil structure in conjunction with the mineral part of the soil. For instance, fresh mushroom compost is practically nutrient-bare stuff (1% N/P/K volume at best, usually, and not all of it is available in plant available forms which is a double-whammy). It's one of the "worst" types of composts you can get your hands on as far as nutrient quality goes, but it's effect on soil structure when combined with the mineral portion of the soil is just as good as any other compost. This post was edited by nc-crn on Tue, Jul 16, 13 at 4:52

I've never used it, but my mom did. A bottle seemed to last forever. Cook's Illustrated on liquid smoke "We were among the many people who assume that there must be some kind of synthetic chemical chicanery going on in the making of "liquid smoke" flavoring. But according to the Colgin Company (which has been bottling liquid smoke since the 19th century), that's not the case. Liquid smoke is made by channeling smoke from smoldering wood chips through a condenser, which quickly cools the vapors, causing them to liquefy (just like the drops that form when you breathe on a piece of cold glass). The water-soluble flavor compounds in the smoke are trapped within this liquid, while the nonsoluble, carcinogenic tars and resins are removed by a series of filters, resulting in a clean, smoke-flavored liquid. Curious about the manufacturing process for this product, we wondered if we could bottle up some smoke for ourselves. To do this, we created a small-scale mock-up of the commercial method, involving a kettle grill, a duct fan, a siphon, and an ice-chilled glass coil condenser. In a comparison of homemade and store-bought liquid smoke, homemade was praised for its clean, intense, smoky flavor. But we spent an entire day and $50 on materials to produce 3 tablespoons of homemade liquid smoke. Commercial liquid smoke is just fine, especially if you avoid brands with additives such as salt, vinegar, and molasses. Our top-rated brand and contains nothing but smoke and water."

Yes. Dry wine can go bad once opened and those liqueurs like Baileys that have cream added. I've had them go bad (so if I plan on serving them, I buy smaller bottles) but I've got some liquor/liqueurs on my shelf in the kitchen that have been there a long time! And we have some opened bottles of whisky and Scotch that are remnants of the Christmas parties we used to have. DH just hasn't managed to work his way through them!

Honestly, I'm not really surprised. While no one should purposely try to inhale or take deep breaths of Powder Laundry Detergent, I've known most of the ingredients in these powders are harmless, and relatively safe. Supposedly however, in the 60's & 70's, when detergents actually contained Phosphate, some phosphorus mines were contaminated with Asbestos, meaning, trace amounts of the stuff were getting into Powder Detergents... but from what I understand, water & washing basically minimized/destroyed any potential health risk. And... the mines that were contaminated, were shut down by the EPA a extremely long time ago. As for Liquid Detergents, I will say... some of them probably could have a single, or multiple carcinogen in them. That truly wouldn't surprise me at all, I feel like many of those formulas are so variable and random, by manufacturer.