The Ultimate Guide to Italian Penicillin: Authentic Pastina Soup

There is a reason why Pastina, affectionately known as “Italian Penicillin,” has remained the go-to remedy for generations of Italian families. When the weather turns cold or you feel the first tickle of a scratchy throat, this humble, soul-warming soup offers a level of comfort that few other dishes can match.

At its core, Italian Penicillin is a simple preparation of tiny pasta cooked in a rich, fortified broth, often finished with a silky egg or a generous dusting of Parmigiano-Reggiano. It is the culinary equivalent of a warm hug. Despite its simplicity, the secret to a truly transformative Pastina lies in the quality of the ingredients and the technique used to emulsify the broth into a creamy, restorative elixir.

In this guide, we will explore the nuances of crafting the perfect bowl, from selecting the right pasta shape to achieving that signature “liquid gold” consistency that has made this dish a staple in kitchens from Naples to New York.

The Components of a Healing Broth

The magic of Italian Penicillin lies in its minimalist ingredient list. Because there are so few elements, each one must be handled with care.

The Pasta (The Star)

The term pastina actually refers to a category of tiny pasta shapes. While Stelline (little stars) are the most iconic and nostalgic choice, you can also use:

Acini di Pepe: Small beads that provide a wonderful texture.
Orzo: A slightly larger, rice-shaped option.
Ditalini: Small tubes that hold a bit more broth.

The Broth (The Foundation)

For a truly medicinal quality, a high-quality chicken bone broth is essential. While store-bought works in a pinch, a homemade stock rich in collagen provides the mouthfeel and nutritional density that defines this dish.

The “Liaison” (The Secret Technique)

Many families whisk an egg and grated cheese into the simmering soup at the very end. This technique, similar to the Greek Avgolemono or a Roman Stracciatella, creates a velvety texture and adds a necessary protein boost.

Ingredients

The Base

6 cups high-quality chicken broth (preferably homemade or low-sodium bone broth)
1 cup pastina pasta (Stelline or Acini di Pepe)
1 small yellow onion, peeled and halved
1 large carrot, peeled and cut into large chunks
1 stalk celery, cut into large chunks
1 clove garlic, smashed

The Finish

1 large egg, room temperature
1/2 cup Parmigiano-Reggiano, freshly grated (plus more for serving)
1 tablespoon unsalted butter (optional, for extra richness)
1/4 teaspoon freshly ground black pepper
Kosher salt to taste
Fresh parsley, finely chopped (optional)

Step-by-Step Instructions

1. Infuse the Broth

Place the chicken broth, onion, carrot, celery, and garlic in a medium heavy-bottomed pot. Bring the liquid to a gentle boil over medium-high heat. Once boiling, reduce the heat to low and simmer for about 15–20 minutes.

Pro Tip: This step “re-fortifies” the broth, extracting the sweetness of the vegetables. After 20 minutes, use a slotted spoon to remove and discard the vegetables (or mash the carrot back into the soup if you prefer a rustic texture).

2. Cook the Pastina

Bring the infused broth back to a light boil. Add the pastina and a pinch of salt. Cook according to the package instructions—usually about 6 to 7 minutes—until the pasta is al dente.

Note: Do not drain the pasta. The starches released by the pastina help thicken the broth into a silky consistency.

3. Prepare the Egg Mixture

While the pasta cooks, whisk the egg and the 1/2 cup of grated Parmigiano-Reggiano together in a small bowl until a thick, pale paste forms. This is the “soul” of the Italian Penicillin.

4. Temper and Incorporate

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 hot pot.

Slowly pour the tempered egg mixture back into the main pot, stirring constantly with a wooden spoon. The broth will immediately transform from clear to a creamy, opaque gold.

5. Final Seasoning

Stir in the butter (if using) and the black pepper. Taste the soup; depending on the saltiness of your broth and cheese, you may need an extra pinch of kosher salt. Remove from heat immediately to maintain the creamy texture.

Expert Tips & Variations

Culinary Secrets for Success

Don’t Overcook: Pastina absorbs liquid incredibly fast. If you overcook it, the stars will lose their shape and the soup will become a thick porridge.
Freshly Grated Cheese: Always use a block of Parmigiano-Reggiano or Grana Padano. Pre-shredded cheeses are coated in cellulose to prevent clumping, which will stop them from melting smoothly into the broth.
The Rind Trick: If you have an old Parmesan rind in your freezer, drop it into the broth during the infusion stage (Step 1) for an incredible depth of umami flavor.

Substitutions and Dietary Adjustments

Vegetarian Option: Use a rich roasted vegetable stock and ensure your hard cheese is a vegetarian-friendly version (as traditional Parmesan uses animal rennet).
Gluten-Free: Use a gluten-free pastina or substitute with white rice. Note that rice will take longer to cook (about 18–20 minutes).
Dairy-Free: Omit the cheese and butter. Whisk the egg with a tablespoon of nutritional yeast to mimic the savory flavor of the Parmesan.

Serving Suggestions

Italian Penicillin should be served immediately in shallow bowls.

Pairing: Serve with a slice of crusty sourdough or toasted ciabatta rubbed with a raw garlic clove.
Garnish: A final swirl of high-quality extra virgin olive oil and a few cracks of black pepper add a sophisticated touch to this humble dish.
Texture Notes: The soup should be “soupy” but substantial. If it sits for too long and becomes too thick, simply stir in a splash of hot water or extra broth to loosen it up.

Storage & Make-Ahead Notes

Refrigeration

Because the pasta continues to absorb liquid as it sits, Pastina is best enjoyed fresh. However, leftovers can be stored in an airtight container in the refrigerator for up to 3 days.

Reheating

When reheating, you will notice the pasta has absorbed nearly all the broth. To restore the consistency, add 1/4 to 1/2 cup of water or broth per serving before heating on the stovetop over medium-low heat. Avoid the microwave if possible, as it can cause the egg-based broth to separate.

Freezing

We do not recommend freezing the completed soup, as the texture of the tiny pasta becomes mushy upon thawing. Instead, freeze the fortified broth separately and cook the pasta fresh when ready to serve.

Preparation Timeline Table

Stage	Duration	Key Focus
Infusion	20 Minutes	Building flavor depth with aromatics.
Boiling	7 Minutes	Cooking the pastina al dente.
Tempering	2 Minutes	Emulsifying egg and cheese for creaminess.
Total Time	~30 Minutes	A quick, restorative meal.

Nutrition Information

Values are realistic estimates per 1.5-cup serving.

Nutrient	Amount
Calories	285 kcal
Protein	14g
Total Fat	9g
Saturated Fat	4.5g
Carbohydrates	36g
Fiber	2g
Sugar	1g
Sodium	840mg

Simple and Delicious Italian Penicillin Soup Recipe for Beginners