Chantilly cream should be velvety in texture and just hold its shape. It will have the best flavor and texture when whipped by hand. If you overwhip it, try folding in some unwhipped cream. If possible, avoid using ultrapasteurized cream, as it does not whip as well or hold its shape when whipped. Do not use powdered sugar to sweeten chantilly cream, as the cornstarch in the sugar gives it a chalky taste.