M: What is the generally accepted technical definition of a quiche? Is there a point at which enough ingredients besides egg have been added that it becomes something else – and if so, what would that be called?
G: TL;DR: A quiche is a savory custard pie made with a pastry crust and a filling primarily composed of eggs and dairy (milk or cream), often mixed with vegetables, meats, or cheese. If the custard ratio is overwhelmed by solids, or if the crust or setting diverges significantly, it may be considered a savory tart, frittata, or savory pie instead.
A quiche is:
Classic example: Quiche Lorraine, with bacon and Gruyère cheese.
A dish may no longer be considered a quiche if:
| Dish Type | Crust? | Egg-Dairy Ratio | Filling Texture | Common Identity |
|---|---|---|---|---|
| Quiche | Yes | High | Soft-set | Custard with extras |
| Frittata | No | Medium-High | Firm-set | Eggs dominate |
| Savory Tart | Yes | Low or None | Dense or layered | Solids dominate |
| Strata | No | Medium | Bread absorbs egg | Breakfast casserole |
| Savory Pie | Yes (often double) | Low | Chunky/Meaty | Meat or veg focused |
If it’s mostly egg and dairy custard, and has a crust, it’s still a quiche. If you’re just using egg as glue for a ton of other ingredients, or eliminating the crust, it becomes something else—often a frittata, savory tart, or casserole.
M: I know chefs quibble. It doesn’t have to be scientifically exact or universal, but have any well regarded chefs, currently or in the past, given any quantitative opinion on when a quiche becomes something else?
G: Yes—while no universal quantitative threshold exists, some respected culinary authorities have provided rule-of-thumb ratios or commentary that imply where the boundaries of "quiche" might lie. Here's what’s been said by influential voices:
Authority: Mastering the Art of French
Cooking
Viewpoint: Julia’s basic quiche custard is 1
egg per ½ cup of cream, often with a 2:1 cream-to-egg
ratio overall.
She warns that too many fillings can disrupt the set or overwhelm the
custard, making it heavy and losing the essence of a quiche.
“The important thing is not to overload it with cheese or solids—you are making a custard tart, not a cheese pie.”
Implication: When the custard stops being the star, it’s no longer a quiche.
Authority: Ratio (book on foundational
kitchen formulas)
Ratio for Quiche:
He emphasizes that too many solids alter the texture and cause the custard to fail or become "dense, clunky pie."
Implication: If solids approach or exceed the volume of custard, it’s not a quiche anymore—it’s a savory pie.
Traditional French culinary schools teach that quiche is about eggs, dairy, and modest additions that suspend in the custard. If the filling can't be poured into the shell or if it bakes up fully solid without any jiggle, it violates the standard.
Many modern chefs on shows like Top Chef and publications like Serious Eats, Bon Appétit, and America's Test Kitchen informally agree:
One memorable Bon Appétit quote (paraphrased):
"If it bakes like lasagna, you're off the quiche map."
| Component | Still a Quiche | Not a Quiche |
|---|---|---|
| Custard volume | ≥ 50% of total filling volume | < 40% of total filling volume |
| Solid ingredients | ≤ equal to custard volume | > 1.5× custard volume |
| Texture (before bake) | Pourable, loose | Thick, heapable |
While no chef draws a strict line in the sand, many—including Julia Child and Michael Ruhlman—imply that once custard is no longer the structural or flavor foundation, it ceases to be a quiche. Their 2:1 dairy-to-egg ratio, plus limiting fillings to equal or less than the custard, is the clearest quantifiable guide to staying in quiche territory.