The Ultimate Italian Penicillin: Authentic Pastina Soup with Lemon and Parmesan

There is a reason why Pastina, affectionately known as “Italian Penicillin,” has remained the ultimate soul-soothing dish for generations. Whether you are fighting a seasonal cold, seeking comfort on a rainy afternoon, or simply craving a taste of childhood nostalgia, this simple yet elegant soup provides immediate restoration.

While the ingredients are humble—tiny pasta shapes, a rich golden broth, and a flurry of salty Pecorino Romano—the magic lies in the technique. Unlike a standard chicken noodle soup, authentic Italian Pastina is creamy, velvety, and deeply savory. In this guide, we will explore the nuances of creating a restaurant-quality bowl of comfort that balances the richness of egg yolks with the bright acidity of fresh lemon.

Why This Recipe Works

The secret to the perfect Pastina is the starch management. By cooking the pasta directly in a measured amount of high-quality broth, we create a “risotto-style” effect where the liquid thickens into a silky sauce. Adding an egg-and-cheese emulsion at the finish transforms a basic clear soup into a decadent, nutrient-dense meal that coats the spoon and warms the soul.

Ingredients

The Base

4 cups high-quality chicken bone broth (preferably homemade or low-sodium)
1 cup Star-shaped Pastina (Stelline) or Acini di Pepe
1 clove garlic, smashed (optional, for infusion)
1 small yellow onion, halved (to be removed later)
1 stalk celery, cut into large chunks

The Enrichment

1 large egg, room temperature
1/2 cup freshly grated Parmesan or Pecorino Romano cheese (plus more for serving)
1/2 lemon, zested and juiced
1 tbsp unsalted butter (European-style preferred)

Finishing Touches

Freshly cracked black pepper
1 tsp fresh parsley, finely minced
A drizzle of extra-virgin olive oil

Step-by-Step Instructions

1. Infuse the Broth

In a medium heavy-bottomed saucepan, combine the chicken broth, smashed garlic, onion halves, and celery. Bring the liquid to a gentle simmer over medium-high heat. Let the aromatics steep for about 8–10 minutes. This step builds a foundation of flavor that sets a “journalist-grade” soup apart from a basic quick meal.

2. Prepare the Aromatics

Using a slotted spoon, remove and discard the onion, celery, and garlic. The broth should be clear, fragrant, and golden. Bring the liquid back to a rolling boil.

3. Cook the Pastina

Add the 1 cup of pastina to the boiling broth. Reduce the heat to medium-low to maintain a steady simmer. Stir frequently with a wooden spoon to prevent the tiny pasta shapes from sticking to the bottom of the pot. Cook for approximately 6–8 minutes, or until the pasta is al dente.

Note: The pasta will continue to absorb liquid even after the heat is turned off, so do not overcook it at this stage.

4. Create the Emulsion

While the pasta cooks, whisk the egg and the grated cheese together in a small bowl until it forms a thick paste. This is a technique borrowed from traditional Carbonara and Stracciatella soups, ensuring a creamy texture without the need for heavy cream.

5. Temper and Combine

Once the pasta is cooked, turn the heat to the lowest setting. Take a small ladle of the hot broth and slowly whisk it into the egg and cheese mixture. This “tempers” the egg, preventing it from scrambling when it hits the main pot.

Slowly pour the tempered egg mixture into the saucepan, stirring constantly. Add the butter and the lemon juice. The soup will instantly transform from a thin liquid to a rich, opaque gold.

6. Final Seasoning

Stir in the lemon zest and parsley. Taste the soup before adding salt—the cheese and broth often provide enough salinity. Finish with a generous amount of freshly cracked black pepper.

Expert Tips & Variations

The Golden Ratio

The most common mistake is using too much pasta for the amount of liquid. Pastina expands significantly as it sits. If you prefer a “soupy” consistency, stick to a 4:1 ratio (4 parts broth to 1 part pasta). If you prefer a porridge-like consistency, reduce the broth by half a cup.

Professional Substitutions

The Pasta: If you cannot find Stelline (stars), use Orzo, Ditalini, or even broken angel hair pasta.
Vegetarian Option: Swap the chicken broth for a rich parmesan-rind broth. Simmer 2–3 old Parmesan rinds in water with carrots and onions for 45 minutes to create a deep, umami-rich vegetarian base.
The Cheese: While Parmesan is standard, Pecorino Romano adds a sharper, saltier kick that cuts through the richness of the egg yolk beautifully.

Dietary Adjustments

Gluten-Free: Use a high-quality gluten-free star pasta or substitute with white rice (adjust cooking time to 18–20 minutes).
Dairy-Free: Omit the cheese and butter; add a teaspoon of nutritional yeast and an extra drizzle of high-quality olive oil for richness.

Preparation and Substitution Guide

Ingredient	Best Substitute	Professional Tip
Pastina	Orzo or Acini di Pepe	Stir constantly to release starches for creaminess.
Chicken Broth	Bone Broth	Use bone broth for higher protein and collagen content.
Parmesan	Pecorino Romano	Always grate fresh; pre-shredded cheese won’t melt smoothly.
Lemon Juice	White Wine Vinegar	Adds necessary acidity to “brighten” the savory fats.

Serving Suggestions

Italian Penicillin is best served in a shallow wide bowl. To elevate the presentation for a formal lunch:

Texture Pairing: Serve alongside a thick slice of toasted sourdough rubbed with a raw garlic clove.
The Garnish: A final swirl of robust, peppery extra-virgin olive oil helps carry the aroma of the lemon zest to the nose.
The Occasion: This is the perfect “restorative” meal. Serve it at the first sign of a tickle in the throat or as a light, elegant starter for a multi-course Italian dinner.

Storage & Make-Ahead Notes

Refrigeration

Pastina is notorious for “drinking” the broth as it sits. If you have leftovers, store them in an airtight container for up to 3 days. Expect the soup to turn into a thick pasta mash—this is normal and quite delicious.

Reheating

To return the soup to its original consistency, add 1/4 cup of water or broth per serving when reheating on the stovetop. Heat over medium-low, stirring gently until the sauce loosens and becomes creamy again.

Freezing

We do not recommend freezing this specific recipe. The delicate egg emulsion and the small pasta shapes do not hold their texture well through the freezing and thawing process.

Nutrition Information

Per Serving (Based on 4 servings)

Nutrient	Amount
Calories	285 kcal
Protein	14g
Fat	12g
Saturated Fat	6g
Carbohydrates	31g
Fiber	2g
Sugar	1g
Sodium	780mg

Note: Nutritional values are estimates based on standard ingredients. Sodium content may vary significantly depending on the broth and cheese used.

How to Make Delicious Italian Penicillin Soup — Quick & Easy!