The drink is fine until the ice melts — then comes that flat, chalky, vaguely stale note. Bad-tasting ice has a short list of causes anywhere, but the Treasure Valley's water chemistry moves one suspect to the front of the line and shortens every filter's honest lifespan. Here's the local decision tree.
Suspect one: the filter, on Boise time
Refrigerator filters are rated "six months" for average water. Our 150–260 PPM hardness is not average — the filter spends its capacity on minerals early, and a cartridge that would coast to month six on Seattle water is loafing by month four here. Past its life, it stops helping and starts contributing: trapped organics give ice that musty basement note. If you can't remember the last change, that's the answer — change it, discard the first two or three harvests, and re-taste before suspecting anything mechanical. (Local corollary: buy real OEM or certified filters; the bargain cartridges fail even faster against hard water.)
Suspect two: the minerals themselves
Hardness that makes it past the filter concentrates as ice freezes — cloudy centers with white flecks, a faint chalky taste, and over time a scale film in the mold and along the fill path that flavors every batch. A machine that's been making ice here for years benefits from a professional clean of the mold and fill circuit; and homes on softeners or reverse-osmosis largely skip this paragraph, which is itself diagnostic — if your neighbor's RO-fed ice tastes clean and yours doesn't, chemistry is your answer.
Suspect three: the bin is a sponge
Ice is frozen air-freshener — it absorbs whatever the freezer exhales. A slow-ice-use household (looking at you, winter) leaves cubes aging in the bin for weeks, soaking up onion, elk roast and freezer-burn perfume. Dump the bin monthly, wash it with baking soda solution, keep strong-smelling food wrapped hard, and park an open baking-soda box in both compartments. If fresh harvests taste fine and old ones don't, the machine was never guilty.
When taste means a service call
A persistent chemical, metallic or plastic note that survives a new filter, a bin scrub and discarded harvests points at the water path itself — an aging inlet valve, a degraded fill line, or scale deep in the system — and that's a parts-and-cleaning visit, not a habit fix. Fixed quote after we test, taste-verified before we leave, and the first clean-tasting glass is usually poured the same afternoon anywhere in the Boise metro.
