Authentic Italian White Sauce Recipe: Silky Dill and Celery Root Emulsion

This authentic Italian white sauce recipe transforms simple ingredients into a velvety emulsion that elevates every pasta dish. The secret lies in slow-cooked celery root and fresh dill, creating a delicate balance of earthy and herbal notes without overpowering the dish.

I developed this version after years of testing traditional sugo bianco techniques, ensuring the sauce remains light yet rich enough to coat noodles perfectly.

The foundation of this sauce is a classic roux made with butter and flour, cooked until golden but never browned—a critical step for authentic flavor. Celery root, often overlooked, adds natural sweetness and body, while fresh dill introduces a bright, aromatic finish.

Unlike heavy béchamel, this version stays silky and light, making it ideal for summer dishes or those watching their fat intake.

What makes this sauce truly special is its versatility. Use it as a base for creamy pasta, risotto, or even as a velvety topping for grilled fish. The emulsion holds together beautifully when reheated, ensuring restaurant-quality results at home. Once mastered, you’ll never reach for store-bought again.

Storage is effortless—this sauce keeps for up to 5 days in the fridge or freezes perfectly for months. For extra richness, a splash of cream or a sprinkle of parmesan can be added at the end. Let’s create this timeless Italian staple.

Ingredients for authentic italian white sauce

Nine ingredients transform into this velvety Italian emulsion—silky, light, and packed with herbal depth.

The celery root is non-negotiable here—it’s what gives this sauce its signature sweetness and body. Most grocery stores carry it near the potatoes, though specialty markets like Whole Foods often have better selection. Look for firm, unblemished roots with smooth skin—no wrinkles or soft spots. Fresh dill is ideal, but dried works at one-third the amount if you're in a pinch. For the butter, European-style brands like Plugrá melt more smoothly than American varieties, but any high-quality unsalted butter will work. The vegetable broth should be low-sodium to avoid overpowering the delicate flavors.

No celery root? Substitute with an extra 0.5 cup diced celery and 0.25 cup diced fennel for a similar earthy note. Fresh dill unavailable? Tarragon or parsley can mimic the brightness, though the flavor will differ slightly. The white wine adds acidity and depth—substitute with extra lemon juice or apple cider vinegar if you're avoiding alcohol. For a dairy-free version, omit the heavy cream and use an extra 0.25 cup vegetable broth. The roux is critical: cook it until it's a pale golden color, but never let it brown or it'll taste bitter.

This sauce freezes beautifully—portion it into ice cube trays for easy single-use servings. Store leftovers in an airtight container for up to 5 days in the fridge. For extra richness, stir in a splash of heavy cream or a sprinkle of grated Parmesan when reheating. The emulsion holds together well when warmed gently, so avoid boiling. If it thickens too much, thin it with a splash of warm broth or water. Leftovers make an excellent base for creamy risotto or grilled fish the next day.

Step-by-step instructions for silky dill and celery root emulsion

Master this classic Italian technique for a velvety sauce with bright herbal notes and subtle depth.

In a medium saucepan, melt the 0.5 cup unsalted butter over medium-low heat. Once fully melted and foaming subsides, whisk in the 0.5 cup all-purpose flour all at once. Cook for 2-3 minutes, stirring constantly with a wooden spoon, until the mixture turns a pale golden color and smells nutty.

This roux forms the backbone of your sauce. If it darkens too quickly, reduce the heat slightly—you want a light color for a clean flavor. The flour should be completely incorporated with no visible streaks, creating a smooth paste that will emulsify beautifully with the broth.

Add the 1 medium celery root (diced) and 2 cloves garlic (minced) to the roux. Cook for 3-4 minutes, stirring frequently, until the celery root softens slightly and releases its natural sweetness. The mixture should smell distinctly aromatic with earthy undertones.

Here's where the authentic Italian flavor develops. The celery root adds subtle sweetness while the garlic provides depth. Don't let the mixture brown—keep the heat at medium-low to prevent bitterness. This step builds the aromatic base that will carry through your entire sauce.

Pour in the 0.25 cup white wine and stir vigorously to scrape up any browned bits from the bottom of the pan. Let it simmer for 2-3 minutes until the wine reduces by about half and the alcohol smell dissipates. This deglazing step captures all the concentrated flavors from the roux.

I always use a dry white wine like Pinot Grigio for this—its crisp acidity cuts through the richness of the butter while adding subtle complexity. If you notice the sauce thickening too much during this step, add 1-2 tablespoons of the vegetable broth to loosen it slightly before proceeding.

Gradually whisk in the 2 cups vegetable broth, about ½ cup at a time, allowing each addition to fully incorporate before adding more. Bring the mixture to a gentle simmer and cook for 8-10 minutes, stirring occasionally, until the sauce thickens enough to coat the back of a spoon.

The key here is patience. You want the sauce to thicken naturally from the starch in the roux, not by reducing too aggressively. If it separates at any point, simply whisk vigorously—this emulsion is designed to be self-correcting. The result should be a smooth, velvety sauce with a glossy sheen.

Remove the sauce from heat and stir in the 0.33 cup fresh dill, 0.25 cup heavy cream (if using), 1 tbsp lemon juice, and 0.5 tsp salt. Let it sit off the heat for 5 minutes to allow the flavors to meld completely. The sauce should be silky smooth with bright herbal notes and a perfect balance of richness and acidity.

This final step transforms your basic roux into an authentic Italian emulsion. The dill adds freshness, the cream contributes richness, and the lemon juice brightens everything. Taste and adjust seasoning—you might need a touch more salt or lemon depending on your broth's saltiness. Serve immediately over pasta or use as a base for seafood dishes.

Best sauces and condiments for this dish

Classic Risotto Base

This white sauce transforms into the perfect risotto foundation when combined with Arborio rice and vegetable broth. Cook 1 cup Arborio rice in 4 cups broth using the same saucepan, stirring frequently for 18-20 minutes until al dente.

The celery root and dill flavors meld beautifully with the rice, creating a creamy texture without added butter. For extra depth, stir in 1 tbsp white wine during the cooking process. 🍚

Seafood Pairings

Use this sauce as a velvety topping for grilled or baked fish like cod or halibut. The bright dill and lemon notes complement delicate seafood perfectly. I like to drizzle 2 tbsp sauce over 6-ounce fillets before broiling at 400°F for 10-12 minutes.

For a complete dish, add ¼ cup chopped parsley and a squeeze of lemon at the end. The sauce's light consistency prevents overpowering the fish's natural flavor. 🐟

Pasta Enhancement

Toss 8 oz linguine or fettuccine with ½ cup sauce per serving for an elegant first course. The celery root adds subtle sweetness that balances the pasta's starchiness. For extra richness, stir in 1 oz grated Parmesan at the end.

I often finish with 1 tsp black pepper and a pinch of red pepper flakes for a touch of heat. This sauce works particularly well with seafood pasta dishes. 🍝

Vegetable Dish Elevator

Roasted vegetables like zucchini, asparagus, or Brussels sprouts become gourmet side dishes when drizzled with this sauce. Toss 2 cups roasted vegetables with 3 tbsp sauce and 1 tbsp olive oil.

The sauce's silky texture coats the vegetables beautifully, adding herbal depth without heaviness. For a complete meal, serve with 4 oz grilled chicken breast or pan-seared scallops. 🥦

Creamy Soups

Stir 1 cup sauce into 4 cups chicken or vegetable broth to create an instant creamy soup base. The celery root and dill provide natural sweetness and aroma without needing heavy cream. For a complete soup, add 1 cup diced potatoes and ½ cup chopped carrots, simmering until tender.

Finish with 1 tbsp lemon juice and salt to taste. This version works beautifully as a light lunch or starter. 🥣

Storage and Reheating

Store leftovers in an airtight container in the refrigerator for up to 5 days or freeze for 3 months. When reheating, warm gently over low heat with 1-2 tbsp water or broth to restore its silky texture.

For extra richness, stir in 1 tbsp heavy cream before serving. I recommend reheating only what you need to maintain the sauce's perfect consistency. ✨

Frequently asked questions