Have you ever had a wine that contained sediment, or salt-like crystals?
According to Wikipedia: "Not all producers decide to thoroughly clarify and stabilize their wines, believing that some of a wine's flavor, aging potential and complexity come from some of the suspended particles. Wine experts, such as Tom Stevenson, notes that techniques like filtration can improve wine quality in moderation but can also diminish quality if used excessively. The consumers of some premium wines (such as Bordeaux and Port) may expect to see tartrates and sediment from a wine that has been aging and not thoroughly filtered."
Sound complicated? All I know is that the wine was delicious!