Dear Dr. Vinny,

Why do only red wines have sediment?

—Shyam C., Kozhikode, India

Dear Shyam,

It’s true that sediment is more likely to occur in red wines than in whites, but white wines can sometimes leave sediment, and whites are also more likely to leave tartrate crystals, which are a different kind of deposit. Both sediment and tartrates are harmless, but people avoid them because their texture can be unpleasant.

I’ve had a lot of sediment questions lately, but to briefly review, most sediment—particularly in young wines—comes from leftover bits of grapes, grape seeds and dead yeast cells that are a normal byproduct of winemaking. But red and white wines are typically made using different methods, and red winemaking simply lends itself to more sediment than white.

In typical red winemaking, crushed grapes and their juice are fermented together, while white wines are usually just made from the juice of the wine. You can think of the smushed-up grapes like a tea bag that “steeps” longer in red wines, while the whites usually get much less contact with those solids. And since those solids are where sediment comes from, it follows that whites will have less sediment in the end.

Separating wine from these grape solids comes later, through racking, fining or filtering, though sometimes a winemaker will choose to bottle a wine without fining or filtering. While there are some terrific unfiltered white wines, I think that most wine lovers expect their whites to be clear, for cosmetic reasons.

—Dr. Vinny