You'll see this phrase (French for "bottled") on the labels of many French wines. It's usually followed by au châ̂teau, au domaine, or á la proprié́té́, all of which are the French equivalent of estate-bottled, meaning that the winery on the label was responsible for both making and bottling the wine. The phrase is intended to imply that a château- or domaine-bottled wine has a higher level of consistency and quality than non-estate-bottled wines or négociant wines, and this is usually the case. If mise en bouteille par is followed by the name of a person, then the wine was handled by a né́gociant.