A crime is reported My coworkers and I share a supply of soft drinks. Last month, one of them mentioned to me in passing that his Diet Pepsi wasn't very good, or else his taste buds were having a day off. The plot thickens A week later, a different coworker said the same thing about her Diet Pepsi. Being a programmer, I'm used to solving problems step by step, so I tried a Diet Pepsi. It seemed ok, so I suggested that they each try one from their supplies at home. They did; one said it tasted odd at home, while the other said it didn't, so I wasn't sure what to conclude. We thought that perhaps Pepsi had tinkered with their formula, but we hadn't heard any news about that. Maybe there was a bad odor in the office that was influencing people's taste sensations, even after they went home? Maybe they both imagined it or one was influenced by the power of suggestion when the other complained? More clues Then, late last week, a can of MY favorite, Diet Dr Pepper, tasted bitter to me. I asked yet another coworker, who also likes Diet Dr Pepper, and he said he thought he was crazy because he discovered that he didn't like Diet Dr Pepper anymore, but realized when I asked him that it was the drink's problem, not his. So it wasn't the power of suggestion and four of us couldn't have had the same imagined sensation. Clearly, two different major soft drink companies wouldn't be tinkering with their formulas at the same time, so we starting suspecting that a batch of drinks had gone bad in our shared refrigerator. But I never heard of soft drinks going bad like this. I looked at the lot numbers on the sides of the cans, but they didn't seem to mean anything. And the listed ingredients (eww) hadn't changed, although phrases like "artificial and natural flavors" might remain the same even if they changed which types of chemicals they used for those flavors. The formal investigation Today we did side-by-side taste tests of the cans we had left vs. some we just bought at the grocery store, and confirmed that the former tasted less flavorful, more astringent, closer to Diet Coke than Diet Pepsi, while the latter tasted the gool ol' way we remembered. I had looked at the lot numbers, but I discovered that the cans also have expiration dates, on the bottoms, in MMMddyy format. It turns out that our supplier (a warehouse place) had sold us expired soft drinks! We called and complained and will get replacements. And it seems that one coworker had old cans at home too. Case solved! One for the files We might have thought to check the dates in the first place, but taste is so subjective that each person thought "it's just me" before we saw the pattern and I started playing Sherlock Holmes. And none of us realized that soft drinks expire. Interestingly, some of the non-diet sodas from that warehouse, which other coworkers drink, had also expired, but nobody noticed a difference in taste. Perhaps their ingredients have a longer shelf life. Soft drinks aren't nutritious anyway, but I didn't know they turn downright evil if they sit around too long! Postscript I have retained full rights to this detective story for when the movie comes out. Who will play me and my three coworkers? Maybe we can get Jack Black to play the warehouse delivery guy. Should I be played by Denzel Washington or by Tony Shalhoub? I hope it won't be Rick Moranis! I can now move on to the next mystery: why the touch-sensitive elevator buttons blink on but don't stay on when you poke them swiftly. If they sense your touch enough to react, why don't they stay on?