White wine sediment? No, just tartrate crystals. Or wine diamonds if you want to sound fancy. Typically looks like chunks of salt or rock candy. Usually caused by storing wine too cold, for too long for example in your fridge. It is quite harmless and a natural by-product of winemaking. To put it into perspective it is the same substance used to make cream of tartar.
Tartaric acid is one of a few types of acid found in wine grapes. Through the process of fermentation and winemaking, it tends to settle out of the wine, but it is extremely sensitive to cold temperatures. Some wineries put their wines through a vigorous cold stabilization process to separate the tartrate crystals out before bottling. However, Marelise, our winemaker prefers not to do this as it can affect the taste and quality of the wine.
So how can you avoid wine crystals? Do not store your wine at less than 10°C. According to Marelise, the ideal storage is a consistent 15°C but anything between 10°C -18°C, as long as it is consistent, will also do the trick.