French Pea Soup (Potage Saint-Germain)

Arguably the best pea soup recipe in the world. An authentic, easy French recipe for Potage Saint-Germain. Historically made with fresh peas - or use frozen when out of season or split peas from the pantry.

So good and healthy, love this recipe, thank you Jill for sharing! - Lidia

Easy Pea Soup Recipe

This isn't a brand new recipe and not one I can call my own that has been developed.

Instead, this is taken from one of The most famous recipe books for chefs by Auguste Escoffier's Le Guide Culinaire (1902). In it, he specifies that the soup's purée base (called 'Saint Germain') is made using fresh peas.

With very few ingredients, it's easy peasy to make and ready in just 35 minutes!

What's in a Potage Saint Germain Soup?

An authentic Saint Germain potage is made with the freshest of peas. You'll need the following basic ingredients:

• fresh peas - but when out of season, use frozen. The modern version has gradually replaced the fresh with split peas from the pantry
• bacon bits or lardons
• leek - include the green part
• carrot - optional as not in the original recipe but I add it to replace the sugar added by Escoffier
• lettuce leaves - optional but add if the soup is too pale if using split peas
• bouquet garni (bay leaf, fresh thyme and parsley).

I also sometimes add an onion - but don't tell anybody, peas. Living on the risky side of life, you say?

Why is the Soup Called Potage Saint Germain?

When I first heard of the soup's name, I was all excited thinking it was from our local town of Saint-Germain-en-Laye just outside Paris. I was wrong. It's a pity because we even have a local baguette called une Saint Germain to go with it!

Instead, the soup's name came from Louis XVI's (16th) war minister, Count (Comte) Claude-Louis de Saint-Germain. He adored fresh peas so much and as he was also a specialist in agriculture, I guess he had green fingers! Although in Larousse Gastronomique, it says it was Louis XV's war minister - so who's correct? Please leave a comment if you have any ideas. Will I still sleep tonight not knowing for sure?

I have tried to find more information about this but alas, all I can find is from our tourist office in les Yvelines. The Count loved the particular fresh peas or petits-pois de Poissy (Poissy is near St Germain). Makes sense: 'Petit Pois Si!' Get it?

shelling peas means green fingers

The Difference Between Split Pea Soup and Pea Soup

There's often some confusion between peas and split peas.

As fresh peas from the pod are not always available in France outside of Spring and Summer, we make this using frozen peas in winter. They're just as healthy and even better if you can use organic ('bio' in France).

Conversely, split peas are dried and a pantry staple all year round. They make pea soup extra thick and need cooked slightly longer than fresh or frozen. They also give a lighter, yellowish colour to the final soup so you may want to green-it-up by adding a few lettuce leaves and more of the green part of the leek.

Do I Have to Soak Split Peas?

Dried split peas ('pois cassés' in French) make a delicious soup but they can take longer to prepare.

While split peas don't have to be soaked in advance, it's preferable to pre-soak them to aid digestion. If you're like me (with IBS) and your stomach hurts after eating split pea soup, it's because they first need to be soaked for at least 4 hours (best overnight). This helps break down many fermentable carbohydrates (FODMAPs), the culprits behind gas and bloating (Drs. Badariotti and Lebrun, 'La Meilleur Façon de Manger Végétal', 2022).

Weigh them out in a large bowl (a third quantity compared with fresh - measurements are given in the recipe card below) and cover with water for 4-8 hours. Always discard the soaking water.

Pea Soup Recipe with Ham

Ideally use a chunk of ham or bacon and cut into small strips. Otherwise use ready-prepared bacon bits or lardons.

• Fry the bacon bits without any oil or butter (there's enough fat in them) for about 5 minutes then add the chopped leeks and carrots.
• Toss them around in the bacon, cover an leave to soften for another 5 minutes.
• Add the fresh (or frozen peas) and bouquet garni.

• Add the water and salt. Bring to a short boil.
• Cover and simmer for 15 minutes (or 20 minutes if using frozen peas).
• Discard the bouquet garni and reserve a ladleful of the peas for a garnish.
• Blitz with a hand blender or mixer to blend the soup until smooth then add the ladle of peas.

For a vegetarian version, simply omit the ham or bacon.

My tip: I often like to replace it with a little smoked paprika to give the impression there's ham in it.

How to Serve Potage Saint Germain

According to chef Escoffier, le potage Saint Germain is served:

"...with a garniture of two spoons of fine, green peas and tufts of chervil leaves." - Auguste Escoffier (Le Guide Culinaire)

So, just before mixing the soup, take out a ladle and set aside. Blend the soup with an immersion blender (or mixer) then add the peas at the end as the garnish.

As chervil isn't always easy to find, use a little fresh parsley or dill. Don't forget the knob of butter to be added at the end of cooking. Serve with a good crusty baguette - or some fluffy cheese scones for my Scottish touch.

For more French soups, try this cauliflower cream soup (Crème Dubarry) and carrot soup (Potage Crécy).