This is often vigorously stirred (use a hand-held mixer) to ensure the liquid whey is reincorporated with the curds; this is referred to as whipped yogurt. Some Indian dishes call for a solid yogurt called hung yogurt. The thicker curd is desired for its firm texture. You can obtain this by simply pouring off the liquid whey if it has already separated, or by placing it in a muslin cloth or paper-lined coffee filter and setting it over a jar or hanging it over the kitchen sink. The whey, or liquid, will drop out and leave behind the yogurt solids.