Celeriac Soup

I’m at a loss as to what to do with the celery. Let’s make celery soup! Beautifully creamy, elegant almost pure white color and low carb. It’s a perfect first course, something different from a dinner party or a leisurely weeknight dinner. It’s so versatile!

Celeriac Soup

A gnarled brown root vegetable that sits quietly in the corner of the grocery store, celeriac is an unsung hero in the vegetable world. We thought it was time to spotlight the star dish of this low-carb marvel!

As you can imagine, celeriac is part of the celery family. The leaves and stems actually look like the thin stalks of celery. However, celeriac eats only bulbs with thick roots and is often sold as a whole.

As you might expect, it also tastes a bit like celery, but with a nutty, earthy flavor. Think of it as a low-carb version of potatoes. Carbohydrates are about 1/3.

Almost anything you can make with a potato can be made with celeriac.

Making soup today! The result is a creamy, silky soup with a texture similar to pumpkin soup.

What you need for Celeriac Soup

First up, the vegetables!

• Celeriac – You need about 1kg / 2lb whole bulb (unpeeled) to yield 800g/1.6lb after peeling. See below for how to peel and chop celeriac;
• Potato – This adds a bit of body and thickness to the soup, being a higher-starch vegetable;
• Garlic, onion, celery and leek – The aromatic base for the soup broth, key for getting enough flavour into this soup which is made using just water, no stock (yes, really)!

Next, the rest of the soup:

• Water – I like that this soup is made with water rather than stock/broth which many soups call for. This keeps the flavour more pure, instead of tasting similar to every other pureéd soup. The trick to boosting flavour is all the vegetables. This soup has a surprising amount, as you can see above. Sautéing them slowly brings out the flavour;
• Cream – Essential for that luxurious mouthfeel and body – especially in the absence of stock – and to give this soup that extra-special touch. I really encourage you not skip it. Remember, the soup is all vegetables other than this cream!!Yes you can opt for low-fat, or evaporated milk as lower calorie options. But it isn’t quite the same …  I’ve given some guidance in the recipe notes;
• Butter – For sautéing the vegetables;
• Herbs and spices – Bay leaf (fresh), thyme, black peppercorns and coriander seeds. These are used to flavour the broth by bundling them up onto a herb and spice sachet. More on why we do this below!

Herb Sachet / Spice Sachet

Called sachet d’épisse in French, it literally means “bag of spices”. This is used to add flavor to the soup so that it doesn’t leave small bits of spice in an otherwise clean white soup.

HOW TO MAKE THE SPICE SACHET

Simply bundle black peppercorns, coriander seeds, bay leaves and fresh thyme in cheesecloth or muslin and tie with string.

Don’t have cheesecloth? It’s totally not the end of the world! Just amend the recipe as follows (actual quantities given in recipe card):

• Use ground coriander instead of whole seeds
• Skip the pepper (we already have pepper in the soup)
• Thyme sprig and bay leaves – Just add them into the soup and remove before blitzing. The thyme leaves will end up dotted throughout the soup, but to remove then you can easily just strain the soup.

How to cut celeriac

I will show you how to cut celery easily. Basically just use a peeler like potatoes! However, the skin is a little tougher and more gritty than a potato, so you’ll need to scrape it a few times to get the skin off (the rough areas are a bit of a pain!)

You can also cut the skin off. Remove with a knife, but you lose more meat.

Despite what other sources may tell you, celery pulp does not oxidize and turn brown quickly, so there is no need to keep chunks in acidic water or the like.

How to make Celeriac Soup

To me, one of the unusually attractive features of this soup is that it’s made with just water, not broth or broth. It means you need to take your time to make sure it has enough flavor to bring out.So don’t rush the saute step!

1. Sauté aromatics for 10 minutes – Sauté onion, leek, celery and garlic for 10 minutes until the onion is becomes sweet and translucent but not golden;
2. Sauté root veg 10 minutes – Add the potato and celeriac and cook for 10 minutes until the outside softens slightly, but again, not golden. Remember, we’re going for a snowy white soup here!
3. Simmer 25 minutes – Add water and spice sachet containing the herbs and spices (more on this below) then simmer for 25 minutes until the celeriac is very soft;
4. Cream – Add cream and simmer for just a few minutes;
5. Blitz! Blend using your method of choice until it’s completely smooth. A stick blender is convenient, but it does take a few minutes and you will need to move it around to blend thoroughly. Blender option – A blender will be faster but be very careful because hot soup in a full, sealed blender can equal a soup explosion. Literally, you will end up with soup on the ceiling or worse, on you  – been there, done that!So let the soup cool for 10 minutes or so, then blend in batches as follows: Fill blender about half way, remove cap in the lid so there’s an open hole. Cover the hole with a folded tea towel, then blitz. Transfer to a separate pot/bowl. Repeat to finish all the soup. Now do you see why I opt for a stick blender? 
6. Done! After blitzing, check to see if the salt is to your taste. The 1 1/2 teaspoons called for in this recipe is just perfectly-seasoned to my taste. If you like saltier / restaurant-level seasoning, you’ll need more.

Garnish with croutons (recipe provided) and something green to add a sprinkle of colour – especially chives, parsley or chervil. A little drizzle of olive oil makes a pretty finishing touch too.

What to serve with Celeriac Soup

Of course, you’re dying for some piping hot buttered crusty bread for dipping. Everyone’s favorite Crusty Artisan Bread hits the spot. . (Both are no-knead miracle recipes that virtually anyone can do!)