Though both varieties are now grown throughout the United States, they were originally imported from vastly different regions. The original Eureka lemons are thought to have been derived from Sicilian seeds and are botanically “true lemons,” meaning that they are not crossbred with other citrus fruits. Meyer lemons, on the other hand, are a hybrid of regular lemons and mandarin oranges. Additionally, they were brought over from China (where they were grown as a decorative plant) in the early 20th century by agricultural explorer Frank Meyer, who realized their culinary potential.
Once you know what you’re looking for, it’s easy to tell the two varieties apart. Eureka lemons have the iconic bright yellow skin, large size and prominent pointed ends associated with lemons, whereas Meyer lemons are smaller, rounder, and darker. Essentially, if the fruit looks like a cross between an orange and a lemon, it’s probably a Meyer lemon.
Texturally, both varieties have differences that you’ll be able to pick up on at first touch. Eureka lemons have a thick, bumpy skin that’s harder to peel than the smooth, thin rind of Meyer lemons. However, both varieties should have a comparable weight for their size.
Due to their mandarin orange heritage, Meyer lemons are substantially sweeter than Eureka lemons. They’re lower in acidity too, but don’t think that makes them more orange than lemon; they still have a tang, albeit a mellower, more approachable one. Additionally, their peels have a greater depth of flavor and a more complex aroma; be on the lookout for spiced tea-like notes in taste and smell.
In general, both Eureka and Meyer lemons run the gamut of culinary possibility, but they can’t always be substituted for each other. For example, Eureka lemons are going to be better suited for marinades, as their high acid content breaks down and tenderizes meat better. On the flip side, you can actually incorporate fresh segments of Meyer lemons into desserts and salads because of their inherent sweetness, which is something you wouldn’t do with Eurekas. In terms of juice, both varieties are fairly interchangeable, but you can create a mixture of the two to get the best of both worlds!