LEMON MERINGUE PIE

THE IDEAL LEMON MERINGUE PIE HAS A rich and lemony filling topped with an airy, nicely toasted meringue. The lemon filling should be soft but not runny, firm enough to cut but not stiff and gelatinous. And the meringue should not break down and puddle on the bottom or "weep" on top—not even on rainy days.

The ingredients in lemon meringue pie have remained constant for some time: sugar, water (or sometimes milk), cornstarch (sometimes mixed with flour), egg yolks, lemon juice (and usually zest), and a little butter. To our taste, the straightforward lemon flavor of the water-based filling is pleasant, but it is also one-dimensional, lacking depth. Milk, however, subdues the lemon flavor. The solution is to rely primarily on water and a lot of egg yolks (we use six rather than the more conventional three), eliminating the milk altogether. This has another benefit: the additional egg yolks allow you to cut back on both sugar (which acts as a softener at a certain level) and cornstarch and still achieve a firm yet tender filling.

The meringue is much more tricky. On any given day it can shrink, bead, puddle, deflate, burn, sweat, break down, or turn rubbery. Most cookbooks don't even attempt to deal with the problems of meringue. They supply the standard recipe—granulated sugar and cream of tartar beaten slowly into the egg whites—assuming, apparently, that some sort of flaw is unavoidable. After making 30-something lemon meringue pies, we're not sure we blame anyone for skirting the issue. For as easy as it was to figure out the perfect lemon filling, the meringue remained, finally, only a manageable mystery.

The puddling underneath the meringue is from under-cooking. Undercooked whites break down and return to their liquid state. The beading on top of the pie is from overcooking. This near-the-surface overcooking of the meringue causes the proteins in the egg white to coagulate, squeezing out the moisture, which then surfaces as tears or beads. This double dilemma might seem insurmountable, but we hit upon a solution.

If the filling is piping hot when the meringue is applied, the underside of the meringue will not undercook; if the oven temperature is relatively low, the top of the meringue won't overcook. Baking the pie in a relatively cool oven also produces the best-looking, most evenly browned meringue. To further stabilize the meringue, we like to beat in a tiny bit of cornstarch; if you do this, the meringue will not weep, even on hot, humid days.