How to Make Avgolemono Without It Curdling

What is avgolemono?

Avgolemono is not a dish, it is a technique: a liaison of beaten egg and lemon juice used to thicken and enrich a liquid. It is one of very few classical thickeners that uses no flour, no starch and no cream, and it gives a texture nothing else quite reproduces, glossy and light rather than heavy.

It appears throughout Greek cooking. Chicken and rice soup is the famous one, but the same technique finishes lamb fricassee, pork with celery, stuffed vine leaves, meatball soup, artichokes and poached fish.

Why does avgolemono curdle?

Egg proteins set at around 70C. Simmering liquid is at 95C or above. Pour beaten egg straight into that and it sets instantly into threads, which is delicious in an entirely different soup and a disaster here.

Tempering solves it by raising the temperature of the egg mixture slowly, so the proteins are diluted and dispersed by the time they meet the bulk of the hot liquid. The acid in the lemon juice helps too, by partially denaturing the protein in a controlled way that raises the temperature at which it will set.

The method, step by step

Beat the eggs hard for a full two minutes, until pale and visibly increased in volume. Air makes the emulsion more stable and this step is routinely skipped.

Whisk the lemon juice into the eggs and combine completely before any hot liquid goes near them.

Take the pan off the heat and let it stop bubbling. Two minutes standing is enough.

Whisking the eggs constantly with one hand, add hot liquid a small ladleful at a time with the other. Do at least four or five additions. By the end the bowl should feel properly hot, not warm.

Pour the tempered mixture back into the pan in a steady stream, stirring. Do not return it to the heat. If it must be hotter, warm it very gently and stop well short of a simmer.

Whole eggs or yolks only?

Whole eggs give a lighter, frothier result. Yolks alone give a richer, more velvety, more stable sauce, because yolks contain the lecithin that does the emulsifying while whites mostly just set.

Whole eggs plus one or two extra yolks is the practical compromise and is what most of the recipes on this site use. If you are nervous, lean towards more yolks: they are considerably more forgiving.

Rescuing a split avgolemono

Mostly you cannot, and it is more honest to say so than to promise a fix. Once the egg has set into visible threads, the texture is gone.

If it has only just begun to look grainy, taking it off the heat immediately and whisking hard can sometimes bring it back. Blending it will make it smooth but flat and slightly foamy. A better use of a split batch is to accept it as a rustic egg-drop version, which still tastes good.

Prevention is the whole game here. Off the heat, slowly, whisking constantly.