Solbar Restaurant Experience in Napa Valley

Pro tips

• Roast onions at 400°F for 30–40 minutes to build color and concentrate sweetness before finishing on the stovetop for full caramelization.
• Use a mix of yellow and sweet onions for complexity—yellow onions provide savory depth while sweet varieties add natural sugars.
• Deglaze the pan with brandy, wine, or sherry after caramelizing to capture browned bits and add depth without harshness.
• Layer your stock addition in stages rather than all at once; this prevents temperature shock and allows flavors to build gradually.

Substitutions

• Yellow onions → sweet or Vidalia onions (slightly less assertive, more pronounced sweetness)
• Beef stock → vegetable or chicken stock (lighter flavor; use chicken for mild savoriness)
• Brandy deglazer → dry white wine or sherry (adjust acidity and aging character accordingly)

Storage & make-ahead

Store in an airtight container in the refrigerator for up to 4 days; reheat gently on the stovetop, thinning with stock or water as needed.

Equipment

heavy-bottomed pot or Dutch oven · wooden spoon for stirring · optional: roasting pan for oven-roasting onions first

How long does it take to properly caramelize onions for this soup?

Deep caramelization typically requires 45–60 minutes of low-heat cooking, stirring occasionally, until onions reach a dark golden-brown color and develop concentrated sweetness.

Can you make roasted onion soup ahead of time?

Yes—the soup actually improves when made 1–2 days in advance, allowing flavors to meld. Store in an airtight container in the refrigerator and reheat gently on the stovetop.

What's the difference between roasted and caramelized onion soup?

Roasting onions in the oven concentrates their natural sugars with less stirring, while stovetop caramelization requires more attention but builds deeper, layered flavors. Solbar's version likely combines both techniques.

Is this soup vegetarian or vegan?

Traditional onion soup is vegetarian if made with vegetable stock, though fine dining versions often use beef or chicken stock for richness. Confirm the base at Solbar for dietary requirements.

How do you prevent onions from burning during cooking?

Use medium to medium-low heat, stir every 10–15 minutes, and add a splash of water if the bottom darkens too quickly. Patient, steady heat is key to even caramelization.