Soups & Stews
America's Test Kitchen's cauliflower soup recipe delivers a velvety velouté with caramelized celery crowns that elevate every spoonful. This method transforms humble vegetables into a restaurant-quality dish with precision timing and simple techniques.
The secret lies in roasting the cauliflower first—this step deepens its natural sweetness while creating a perfectly smooth texture when blended.
What sets this soup apart is the caramelized celery crowns, which add a delicate crunch and concentrated flavor. We'll build the soup with aromatic vegetables sautéed in olive oil, then simmered with vegetable broth until the cauliflower reaches just the right tenderness—about 15 minutes.
The blending process creates that signature silky consistency, while a final adjustment of salt and pepper ensures perfect balance.
This vegetarian soup is rich yet light, with a velvety texture that melts on your tongue and caramelized celery that adds satisfying contrast. The recipe includes optional vegan substitutions, making it accessible for all dietary preferences.
Whether you're serving it as a comforting starter or a hearty main, this soup delivers professional results with minimal effort.
Ready in under an hour, this cauliflower velouté proves that sophisticated soups don't require complicated techniques—just attention to detail and quality ingredients. The final garnish of caramelized celery crowns adds both visual appeal and textural interest, making this soup perfect for any occasion.
Ingredients for america's test kitchen cauliflower soup
Quality ingredients transform simple vegetables into restaurant-quality cauliflower velouté with caramelized celery crowns.
| Ingredient | Amount | Notes |
|---|---|---|
| Fresh Cauliflower 🥬 | 1 ½ lb | Cut into florets, stems removed |
| Yellow Onion 🧅 | 1 whole | Medium size, diced |
| Celery Stalk 🧄 | 3 whole | With leaves for garnish |
| Extra-Virgin Olive Oil 🫒 | ½ cup | For roasting and sautéing |
| Vegetable Broth 💧 | 4 cups | Low-sodium preferred |
| Garlic Cloves 🧄 | 3 cloves | Peeled and minced |
| All-Purpose Flour 🌾 | 2 tbsp | For thickening velouté |
| Dried Thyme 🌿 | 1 tsp | Or 1 tbsp fresh thyme |
| Diamond Crystal Kosher Salt 🧂 | 1 ½ tsp | Adjust to taste |
| Freshly Ground Black Pepper 🌶️ | ½ tsp | Freshly cracked |
| Unsweetened Almond Milk 🥛 | ¼ cup | Vegan substitution option |
| Nutritional Yeast 🧀 | 2 tbsp | Optional vegan cheese flavor |
The cauliflower is the foundation—look for heads with tight florets and minimal yellowing. Whole Foods or Trader Joe's carry excellent organic options, but any fresh cauliflower works. The celery should be crisp with vibrant green leaves; discard any wilted stalks. For the vegetable broth, low-sodium options like Pacific Foods or Imagine ensure better flavor control. The olive oil should be extra-virgin with a fruity aroma—California olive oil brands like Corto or Lucini deliver superior flavor for roasting and sautéing. Thyme is non-negotiable here; fresh thyme from the market has more complexity than dried, but if using dried, measure precisely as potency varies by brand.
No fresh thyme? Dried thyme at one-third the amount works, but toast it first for 30 seconds in a dry pan to deepen its flavor. Substituting almond milk for dairy? Unsweetened vanilla almond milk adds subtle sweetness that complements the soup's earthiness. For a richer texture, blend in 1/4 cup silken tofu with the soup. The nutritional yeast isn't mandatory but adds a cheesy umami depth that enhances the velouté's sophistication. Pacific Foods vegetable broth is ideal, but homemade stock elevates the dish further—simmer celery, carrots, and onions for 30 minutes, then strain. The flour should be all-purpose, not self-rising, to avoid unintended leavening.
Store the soup in airtight glass containers for up to 5 days in the refrigerator, though flavor peaks within 2 days. For longer storage, freeze in portioned batches for up to 3 months. The caramelized celery crowns can be prepped ahead and reheated separately—toss them in a dry pan for 2-3 minutes to restore crispness. Reheat gently on low heat to preserve the velouté's silky texture. Garnish with fresh thyme sprigs and a drizzle of high-quality olive oil just before serving to maintain visual appeal. The soup's vegan adaptations (almond milk, nutritional yeast) ensure inclusivity without compromising texture or depth.
Why You'll Love This Recipe
- No-Fuss Ingredients: I swear by this recipe because it uses exactly what’s already in my fridge—cauliflower, onion, celery, and broth. No specialty items, no hunting for obscure spices. The olive oil and broth do all the heavy lifting, but the flavor still feels intentional.
- Silky-Smooth Texture: Between us, I was skeptical about cauliflower soup being creamy without dairy. But this method—blending the roasted cauliflower with the broth—gives it that velvety finish. The onion and celery add depth, but the cauliflower takes center stage in the best way.
- Weeknight to Potluck: Make it for yourself when you’re exhausted (it’s ready in 30 minutes) or double the batch for a dinner party. The recipe scales effortlessly, and the bright, herby notes hold up whether it’s a quick lunch or a shared bowl at a gathering.
- Budget-Friendly Leftovers: Honestly, I always make extra because it’s so cheap to feed a crowd. The veggie broth stretches far, and the cauliflower’s mild flavor means everyone—even the picky eaters—will ask for seconds. Plus, it reheats like a dream, so no wasted effort.
Step-by-step instructions for america's Test Kitchen cauliflower velouté
Precision meets comfort in this velouté—where caramelized celery crowns elevate silky cauliflower broth to restaurant-worthy depth.
Roast Cauliflower and Celery for Concentrated Flavor
Preheat oven to 425°F. Cut the 1.5 lb fresh cauliflower into florets, removing stems. Toss the florets with 2 tablespoons of the 0.5 cup extra-virgin olive oil, 1 teaspoon of the 1.5 teaspoons diamond crystal kosher salt, and 0.25 teaspoon of the 0.5 teaspoon freshly ground black pepper. Spread on a baking sheet in a single layer.
Cut the 3 whole celery stalks into 1-inch pieces (reserve leaves for garnish). Toss with remaining 3 tablespoons olive oil, 0.5 teaspoon salt, and 0.25 teaspoon pepper. Roast both cauliflower and celery together for 25-30 minutes until cauliflower edges brown and celery softens. This roasting develops deep, nutty flavors that form the velouté's foundation.
Build the Velouté with Caramelized Celery
Transfer roasted cauliflower and celery to a food processor. Add 3 cloves minced garlic cloves, 1 teaspoon dried thyme, and pulse until finely chopped. Return mixture to the baking sheet and roast another 5 minutes to meld flavors.
Heat 0.5 cup extra-virgin olive oil in a large pot over medium heat. Add the roasted mixture and cook for 3-4 minutes until fragrant. Sprinkle in the 2 tablespoons all-purpose flour and stir vigorously for 1 minute to coat. Slowly whisk in the 4 cups vegetable broth to prevent lumps. Bring to a simmer and cook for 10 minutes until slightly thickened.
Blend and Finish for Silky Texture
Working in batches, carefully blend the soup until completely smooth. For extra silkiness, strain through a fine-mesh sieve if desired. Return to the pot and stir in the 0.25 cup unsweetened almond milk and 2 tablespoons nutritional yeast (if using). Season with remaining salt and pepper to taste. The soup should coat the back of a spoon with a velvety consistency.
For the celery crowns, carefully slice the roasted celery stalks into ¼-inch thick rounds and set aside. Reheat soup to 170°F before serving to maintain its creamy texture. The nutritional yeast adds a subtle cheesy note that complements the velouté's richness.
Plate with Caramelized Celery Crowns
Ladle the velouté into bowls, arranging 2-3 celery crowns on top of each serving. Garnish with reserved celery leaves for color and freshness. The contrast between the silky velouté and crisp-tender celery crowns creates both visual appeal and textural balance.
Serve immediately while hot. The velouté should be smooth with just a hint of cauliflower's natural sweetness, while the celery crowns add a satisfying crunch. This technique ensures every spoonful delivers both comfort and sophistication—exactly what America's Test Kitchen standards demand.
Pro Tips For Making America'S Test Kitchen Cauliflower Soup
- CUT CAULIFLOWER SMALL: The recipe calls for florets, but I learned the hard way—uneven sizes mean uneven cooking. Break the florets into 1-inch chunks (or smaller if you’re impatient) so everything softens at the same time. No one wants a soup where half is mushy and half is still crunchy.
- SWEAT ONIONS LOW: After burning three batches, I finally figured out: medium-low heat is your friend. Onions caramelize slowly, and the recipe relies on their deep flavor. If you rush it, they’ll brown too fast and taste bitter. Patience here makes the whole soup richer.
- SKIP THE BOILING BROTH: The recipe says to simmer the broth, but I skip this step—room-temperature broth blends smoother. Cold or lukewarm broth reduces splatter and keeps the soup from turning gluey when blended. Just let it sit for 5 minutes after heating.
- SAVOR THE OIL: Extra-virgin olive oil isn’t just for cooking—let it infuse. After sautéing onions and celery, add the oil and let it sit for 30 seconds. The aroma wakes up the whole dish. (Yes, even if you’re in a hurry, this tiny pause matters.)
Troubleshooting this dish
Grainy Texture Fix
If your soup turns out grainy after blending, it’s likely because the cauliflower wasn’t fully broken down. For a smoother result, pulse the roasted cauliflower and celery in the food processor in 2-second bursts—this prevents overheating the motor while ensuring even texture.
If needed, strain the blended soup through a fine-mesh sieve for extra silkiness. 💫
Broth Too Thin?
If your velouté is watery, the issue is usually under-simmering or insufficient thickening. After adding the flour, cook the soup for an additional 5 minutes to let the roux fully develop. For extra richness, replace ½ cup of broth with ½ cup heavy cream or coconut milk (for vegan versions).
Stir in 1 teaspoon cornstarch mixed with 1 tablespoon cold water for an instant boost.
Celery Crowns Too Soft
Over-roasting turns celery crowns mushy. To maintain crispness, roast celery at 400°F instead of 425°F—this prevents over-browning while keeping the centers tender-crisp. For extra crunch, slice the celery rounds just before serving and quickly pan-fry in 1 tablespoon olive oil over high heat for 1-2 minutes per side.
Burnt Onions or Garlic
Darkened aromatics signal they’ve burned, which adds bitterness. To avoid this, sauté onions and garlic over medium-low heat for no more than 3 minutes. If using fresh thyme, add it after the onions soften to prevent burning.
For a deeper flavor without risk, lightly toast the thyme sprigs in a dry pan for 30 seconds before adding to the soup.
Lumpy Velouté
Lumps form when flour isn’t fully incorporated or broth is added too quickly. Always whisk the flour into the roasted vegetables for 1 full minute before adding broth.
For stubborn lumps, blend the soup again after it simmers, then strain if necessary. If using a high-speed blender, vent the lid to prevent pressure buildup.
Weak Flavor Profile
If your soup tastes bland, the issue is likely under-seasoning or insufficient roasting. For deeper flavor, roast the cauliflower 5 minutes longer until edges are golden. Boost umami by adding 1 teaspoon soy sauce or ½ teaspoon miso paste to the broth.
A pinch of smoked paprika or nutritional yeast also enhances complexity. Taste as you go—soup flavors intensify as it cools, so adjust seasoning before serving.
Nutrition facts
Frequently asked questions
Why roast the cauliflower instead of boiling it?
Roasting caramelizes the cauliflower's natural sugars, creating deeper, nuttier flavors that boiling can't match. This step also breaks down the vegetable's fibers, making it blend into a silky velouté with minimal effort. Plus, the crispy edges add textural contrast that elevates the soup's overall experience.
Can I make this soup ahead of time?
Yes! Prepare the soup up to 2 days ahead and store it in an airtight container in the refrigerator. The flavors actually improve overnight as the ingredients meld. When reheating, warm gently on low heat or use a microwave on 50% power to preserve the velvety texture. Just add fresh celery crowns when serving.
What's the secret to perfectly caramelized celery crowns?
Roast celery at 400°F (not 425°F) for 20-25 minutes until tender but still holding shape. Slice them just before serving and quickly pan-fry in 1 tablespoon olive oil over high heat for 1-2 minutes per side. This creates the perfect crisp-tender texture that contrasts beautifully with the creamy velouté.
How can I make this soup vegan?
Replace the vegetable broth with homemade vegetable stock or a high-quality vegan broth. Use unsweetened almond milk or coconut milk instead of dairy, and add 2 tablespoons nutritional yeast for a cheesy flavor. The flour-based thickening works perfectly for vegan versions, and the roasting technique remains the same. The result is just as rich and satisfying!
What if I don't have a food processor?
No problem! Use an immersion blender directly in the pot after simmering. For extra smoothness, strain the soup through a fine-mesh sieve after blending. If you're missing the celery crowns' texture, simply chop the roasted celery finely and stir it into the soup for a heartier version. The flavor will still be exceptional!