Why Does Syrup Collect Under Meringue?

The first cause is sugar that has not fully dissolved. If undissolved granules remain in the foam when beating is finished, they draw moisture from the air and small syrup droplets form around them. The droplets gradually merge, trickle down through the foam, and leave a pool under the dessert. That is why sugar is added a little at a time and the mixture is beaten until the granules disappear. To make sure the sugar has dissolved, rub a little of the mixture between your fingers and check for any grains.

The second cause is a temperature difference. When meringue is spread over a cooled filling, an interface remains between the 2 of them; vapor from the filling condenses at this cold boundary and collects as water. That is why, for fruit or cream desserts, meringue is spread while the filling is still hot. The hot filling also lightly cooks the underside of the meringue so the 2 really adhere to each other. If the filling has cooled, return the dessert to the oven for a few minutes to warm it, then add the meringue. A filling fresh from the oven works best because its steam is still rising.

The third cause is the edges. If meringue is piled in the center of the dessert and a gap is left around the edge, the meringue contracts as it bakes, pulls back from the gap, and lets air underneath. That air brings moisture with it. Bring the edge of the meringue all the way to the edge of the crust or pan and seal it completely; this leaves no enclosed space underneath and keeps the meringue from sliding as it bakes. Leaving peaks with the tip of a spoon as you spread the meringue also gives it an attractive pattern of color in the oven.

Golden droplets that appear on top of the meringue are a separate issue. They are not the same as the pool underneath; they come from overbaking. When meringue stays in the oven too long, its proteins tighten too much and push out the water inside. The solution is to bake the meringue for less time and at a more moderate temperature; remove it as soon as the surface turns golden. The longer it stays in the oven, the more droplets appear, so watch the dessert while it bakes.

Humidity and waiting time also affect the result. On humid days, meringue draws moisture from the air and the problem gets worse. Meringue desserts should not be kept in the refrigerator for a long time because condensation speeds up in the cold. The best result comes from eating the dessert the day it is made; store leftovers in a sealed container in the refrigerator, but expect them to have a different texture the next day. If you dip the knife in hot water and wipe it after each cut, slices separate without crushing the meringue. Do not stack leftover slices; touching meringue surfaces merge and become watery within a few hours.