Lemon Meringue Pie Day – Nutrition and Food Safety (2024)

I want to help you produce a pie with that perfect firm, silky filling that cuts beautifully yet melts in the mouth. I know I’m not alone in my troubles with lemon meringue pie. I’ve seen plenty of soupy pies and botched meringues.

It isn’t necessarily the recipe that was dooming the pie filling, it was chemistry. The elements that make up the filling for this pie don’t get along. Why are they not a happy mix?

Limiting Factors

We rely on starch to thicken the lemon filling. Unfortunately, the lemon juice, the heat you’re cooking over, the fat, and even enzymes in raw eggs can all work against the thickening ability of starch.

Another problem is my love of extra tart lemon filling. The acid in the lemon limits the ability of starch to capture moisture, contributing to the pooling in the bottom of the pie plate. We need to use enough juice to provide the lemon flavor but not so much that the starch can’t do its job. Using less sugar is a better means of keeping things tart. This will also assist the thickening ability of the starch since sugar can also inhibit the thickening ability of starch.

The next issue is heat. Some recipes try to solve the loose filling problem by cooking the mixture longer to reduce the excess moisture content in the filling. This isn’t a good idea since starch has limits when it comes to heat. Let me explain…when you heat a mixture of starch and water, water is able to enter the starch granules. The granules swell and reduce the free water in the mixture, components of the starch are then released into the mixture, changing the viscosity of the mixture and thickening it. However, if your mixture gets and stays too hot, the starch granules can “break down,” releasing their liquid back into the mixture and reducing the viscosity of your pie filling.

Mixing is another problem. During cooking, if you vigorously stir or whisk those hot, swollen starch granules, it can also cause them to burst. Continuing to stir after being removed from heat is also ill-advised. The amylose released from the starch granules will be doing the final job of setting the pie filling. To do this, it forms a fragile network structure between the granules and the gel, which traps the remaining liquid. This isn’t the most forgiving network, and stirring the filling as it cools will destroy the nice, firm, silky texture we want.

Meringue

Now, let’s take a minute to talk meringue. I realize meringue can be a thorn in the side of many home bakers. There are three types of meringue, the one made most commonly at home is French meringue, which is made by whisking sugar into beaten egg whites. Swiss meringue is made by beating egg whites and sugar together over a pan of hot water until the sugar has dissolved, then beating until the mixture reaches stiff peaks. Italian meringue is made by whisking a hot sugar syrup into beaten egg whites. It is the most difficult to make but is popular with bakers and caterers as it tends to hold its volume well.

The soft French meringues that typically top lemon meringue pies are pretty unstable. If poorly made or just given enough time, the structure that makes up the meringue will break down, and this will allow for the release of moisture and sugar, which is known as weeping. There are a few tricks and tips to minimize weeping, although execution is important.

The meringue, when made, should incorporate cream of tarter, which is often left out during its preparation. This stabilizes the mixture and prevents the egg whites from separating. Also, excessive whipping can cause the meringue to separate, as does an inaccurate amount of sugar added to the egg whites.

A cornstarch infused meringue seems sturdier, less prone to weeping, and comes with the added bonus of a silky mouth feel and cleaner cuts.

Using 4 large egg whites and 1 cup of superfine sugar is a two-to-1 1 ratio by volume, which produces the high meringue requisite to this pie. You can easily make superfine sugar by processing regular granulated sugar in the food processor for a minute or two.

Preparation Tips

Always start on a low speed until the eggs start to foam. Then finish on medium speed. High speed on the mixer causes the egg whites to separate, and the formation of the meringue can occur too quickly, and control of the meringue is lost. The idea is to slowly incorporate air into the mixture, not breaking down the egg whites.

Hot or Cold?

Some feel that meringue should be put on a piping hot filling, as it provides heat to the bottom of the meringue while the heat from the oven cooks the top. However, with mile-high meringues, it can be difficult to ensure adequate heat throughout, and by the time the pie filling cools enough to serve it, you may find yourself with a bit more moisture than desired. Yet there are those who say the meringue should be put on top of a room-temperature filling. They believe the hot filling is what causes the sugar in the meringue to liquefy when condensation occurs due to the heat.

Others feel that the meringue is best put onto a chilled pie. Simply top the chilled pie with meringue right before serving, bake, and then slice and serve at its structural peak. This is probably the easiest means of avoiding weeping for this particular pie.

In addition, ‘sealing’ the meringue to the crust before baking helps prevent the meringue from slipping off the top of the pie when serving.

Browning

During the browning stage of the meringue, the oven will tend to cause the sugar to further absorb the moisture from the eggs and cause it to become “syrup-like.” Low temperatures in the oven are the culprit. Pre-heat and set your oven to “broil” then place the pie on the shelf lowest to the heating source. Watch the pie brown. It only takes a minute or two to do so. If necessary, rotate the pie for even browning and quickly remove it. Allow it to cool to room temperature before putting it in the fridge.

Weeping

However, none of these methods will save you from the headache of weeping if you attempt to store the pie for long periods or make the meringue poorly. Under-beaten or over-beaten/broken meringues cannot maintain their structure or hold onto their moisture. Following these rules, the meringue will stay attached for days in the refrigerator with no weeping either on your part or the part of the meringue and without the filling becoming watery if it is kept for several days.

Lemon meringue pie is best eaten the day it’s made, but leftovers will keep, loosely tented with aluminum foil and refrigerated, for up to 3 days. Never cover with plastic wrap—too much condensation will form under the wrapping. See below for a delicious Lemon Meringue Pie recipe. Enjoy!

Written by Vicki Hayman, MS, University of Wyoming Extension Nutrition and Food Safety Educator

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Email: nfs@uwyo.edu

Extension Educator:
Vicki Hayman – (307) 746-3531

Issued in furtherance of extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Kelly Crane, Director, University of Wyoming Extension, College of Agriculture and Natural Resources, University of Wyoming Extension, University of Wyoming, Laramie, Wyoming 82071.

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