Greek yogurt

Greek yogurt is, microbiologically, the same product as standard set yogurt — the same Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, the same fermentation, the same end pH. What distinguishes it is a finishing technique applied after fermentation: the finished yogurt is strained through cheesecloth, butter muslin, or a specialized straining bag for 2-12 hours in refrigeration, removing approximately half its volume as whey. The result is a yogurt three to four times thicker than the standard set, with a fat content (in the strained portion) roughly doubled, and a strikingly different mouthfeel and culinary utility.

In Greek cooking, the strained yogurt occupies a different role than thinner yogurts. It is the base for tzatziki — combined with grated cucumber, garlic, dill or mint, lemon juice, and olive oil — where its body holds the sauce together. It is eaten with honey and walnuts as a dessert. It is used as a sauce for grilled meats, where its higher density resists weeping under heat. The standard yogurt of supermarket-style runny consistency would not perform any of these roles.

The editorial position is that Greek yogurt is best understood as a finishing technique, not a separate ferment. The fermenter who masters one yogurt has mastered both; the difference is whether the finished product is strained or not. The marketing-driven proliferation of "Greek-style" supermarket yogurts has, in recent years, included thickening agents like milk protein concentrate, gelatin, or modified starch — products that achieve thickness through additions rather than through straining. These should not be confused with the actual preparation.

The whey that drains off during straining is itself useful: it can be used as the liquid in bread doughs (the lactic acid contributes to fermentation), in marinades for chicken (it tenderizes), in lacto-fermented vegetable starters, or as a tangy addition to smoothies. Discarding it is wasteful but common; collecting and using it elevates the practice.