Is my Sauternes damaged??

Most likely you just have a deposit of fine tartrate crystals. If so, this is a most common thing that will not harm the wine at all. They can be prevented by chilling the wine before bottling and filtering the deposit formed out, but there is no need to do so. Tartrate crystals are very common in some German Rieslings of the highest quality. I have seen old bottles of German TBA, of the highest quality, that have a huge amount of tartrate deposit, but this does not harm the wine at all. There is a slight chance something else has caused the deposit, but I would not worry about it. Since you have 3 half bottles, perhaps you could open one soon if you are worried. Just pour the wine carefully to avoid the solids.

Completely harmless: These are crystal of potassium bitartrate, a salt of tartaric acid. The precipitation happens at cold temperatures. Quite often this is done during winemaking, the vats are cooled down to -2°C (28°F) for a week or two to induce precipitation. But quite often this is not done, so it happens in the cellar, if cellar temperatures are lower than what the wine encountered during its making and transportation.

M.

Relax. These are Tartarate crystals and have no effect on the wine. If they persist, just decant the wine an hour before serving.

Not a problem!

Peter Taylor

Not only is it not a problem (fully edible but crunchy), "wine crystals" are often an indication of intensity and extract.

With German wines, my experiences have always confirmed that their presence fortells the drinking of a great wine. Sometimes (for reasons I cannot explain) they will partially or entirely re-absorb back into the wine over time.

LarryB