How to Prevent Ice Crystals in Frozen Soufflés

If the frozen lemon souffle caught your eye, then you are at the right place for we have some tips to counter the most common trouble associated with such a dessert – formation of ice crystals. We highly recommend reading on if you are seriously debating freezing a batch or a whole container to make the perfect frozen lemon soufflé with pistachios & Oreo crumble.

Chill the Citrus Curd Well

It is imperative to cool the citrus curd right after cooking the citrus custard with the juices, sugar, and eggs in it. You need it to cool down quickly, and the best way to do that for the hot custard is to put the custard bowl in an ice water-filled larger bowl to chill it. This step will help the custard prevent the water content in it from turning into ice crystals, that might just make for a gritty dessert. To make sure this doesn't happen further, stir the curd occasionally every now and then. This will keep the citrus curd smooth, and also help in keeping the temperature even, so the curd doesn’t form lumps or any skin that will affect the smoothness of the frozen soufflé later.

Whipping the Egg Whites and Cream Correctly

This is where most of the goof-ups happen, as getting the technique right comes to the fore; to get this right, you need to follow the recipe closely. This recipe calls for the egg whites to reach stiff peaks, which means the egg whites, once whisked, hold their shape well when you lift the whisk from them. As for the cream, you need to whip it a tad lesser, for it to form medium peaks – not too soft, but not too firm. This will help the cream get the light, airy quality you need without it collapsing or being too dense. When it comes to combining the whipped egg whites and cream with the cooled citrus curd, make sure to be gentle. Use a spoon or spatula and fold everything slowly in gentle motions until just combined, without stirring.

Incorporate Glycerin or Alcohol

The goal for this unique dessert is to stop any ice crystals from forming. This step is an extra precaution, but for those who are too careful, try adding a little glycerin (about ½ tsp). The glycerin helps keep the soufflé smooth and prevents big ice crystals from forming while it freezes. You can also add a little bit of alcohol to the soufflé mix if no kids are consuming it. Like the Italian limoncello, this addition helps because the alcohol lowers the freezing point of the soufflé to a degree. Because of this, the dessert freezes slower, which results in smaller, finer ice crystals that won't affect the smoothness of the soufflé.

Even Freezing is the Goal

Put the soufflé in the center of the freezer so it evenly chills and also make sure that your freezer is at a constant, cold temperature (about -18°C preferably). If the temperature keeps fluctuating, chances are big ice crystals will form in the soufflé, given the uneven chilling, exactly what you need to avoid. Now, let’s tackle the individual portions vs a whole compact batch. Freezing your soufflé in individual ramekins or smaller molds is your best bet as it freezes better, faster, and more evenly in smaller portions, ensuring a creamier mouthfeel and tinier ice crystals if any. Larger ones are also okay, but the probability of bigger crystals is higher, but the chilling temperature can counter that neatly.

Use Cornstarch or a Stabilizer

This step is entirely optional, but adding a small amount of cornstarch (just 1 tsp) to the citrus custard can help make the soufflé thicker and creamier. This also helps stop large ice crystals from forming. It’s like adding a tiny bit of thickener to your curd to help it hold its smoothness as it freezes. Instead of cornstarch, you can opt for the likes of agar-agar or gelatin to further thicken the curd, which can help your frozen soufflé keep its shape and smoothness. These act as a binding agent, keeping everything in place as it freezes. If you use these, be sure to follow the instructions carefully, as adding too much can change the smoothness of your dessert.