Winemaking in a qvevri, whether for red or white wines, is conducted along similar lines and relies on naturally occurring yeasts (rather than added cultures). After the grapes are crushed, the juice, skins, stems, and pips are transferred to the qvevri, which is then sealed. To include solids of this sort may be broadly typical of red wines vinified in tanks following international methods, but it is exceptional for white wines. As a consequence, qvevri whites take on much darker colors and degrees of tannin from lengthy contact with skins and stems. This is the origin of amber or orange wines, as these whites have come to be called. Some examples are strikingly dense in color, perhaps even cloudy, and have assertive flavors and degrees of astringency unfamiliar to most wine drinkers.