When it comes to Tarte au Citron, it’s best to keep it simple. While it’s true that a Tarte au Citron possesses an air of elegance and Parisian grace – it shouldn’t be fussy. There’s no place for sky-high meringues or Cool-Whip toppings. We’ve got perfectly good lemon meringue and Key lime pies to fill that niche. Tarte au Citron is something else altogether – best served with nothing more than a sprinkle of zest. Though I wouldn’t object to a dollop of barely sweet, lightly whipped cream (as long as it were served on the side). A well-made Tarte au Citron has a one-two punch of sweet-tart that’s dazzling all on its own.
It’s success lies in the vim of a slim but zippy filling barely supported by a delicate sweet-pastry crust – what those elegant Parisians call Pâte Sucrée. I’ve added a wisp of zest to the Pâte Sucrée in my Tarte au Citron for a second set of of sweet-tart jabs. I think it’s a nice touch.
Limes are key to this Tarte au Citron Vert so use Key limes (also known as Mexican limes where I live) if you can find them. After all, you’ll want a tart tarte. But not too tart. This balance cannot be achieved with lime juice and sugar alone. Well actually it can be achieved with lime juice and sugar alone if you choose the right limes. As I said limes are key, and Key limes have the right ripe pucker.
I realize you may not have a choice. If you can’t find Key limes you can use standard-issue limes from the grocery store. However, let them sit on the window sill for a few days after you buy them. They should begin to turn yellow. That’s when they’re at their juicy best. I’ve found that limes in the grocery store are often sold too “green”. Green limes have an astringency that can be unpleasant. The easy mistake is to overcompensate for the unpleasant pucker by adding more sugar. A ripe lime will have a sour tang, but it also has the natural sweetness from its own fully-ripened sugars. Which makes for a tart tarte with with a sweet demeanor. GREG