Slow Cooker French Onion Soup Recipe (2024)

FAQs

How do you deepen the flavor of French onion soup? ›

A few sprigs of thyme and a bay leaf elevate the soup even more, but I take it a step further, adding a splash of fish sauce for complexity and depth—don't worry, it won't taste fishy—and a hit of cider vinegar to balance some of that oniony sweetness.

Never add onions to a slow cooker dish that you haven't sautéed first – I find you get that slight raw onion flavour throughout and it just ruins the dish for me. I really think it's worth the extra effort. It's the only ingredient I bother to pre-cook! Everything else you can chuck straight in.

Can you overcook something in a slow cooker? Slow cookers are specially designed to cook food for long periods of time, but yes, you can still overcook in a slow cooker if something is left on the wrong setting for longer than it's supposed to be.

The caramelized onions for this soup cook more quickly due to a pinch of baking soda but still have that deep, slow-cooked flavor. Topping the soup with hot, cheesy toasts prepared while the soup simmers, eliminates the need to bake the soup in specialty French onion soup bowls.

Most likely it could be from not caramelizing the onions long enough, as this is crucial for flavor development. Also, be sure to use a good quality broth and season the soup properly with salt and pepper. You can try adding a splash of balsamic vinegar or Worcestershire sauce for a boost of flavor.

If you don't add enough salt, pepper, or other herbs and spices, the soup may taste bland.

After 10 hours, the onions will be golden-brown and soft, and they will have released a lot of liquid. If you like them as they are now, stop cooking and pack them up.

Under alkaline conditions, the red hue changes to a bluer tinge. If you cook red onion with alkaline foods, such as nuts, lentils, and some vegetables, those anthocyanins revert to their blue hue. The same is true of red cabbage.

Low: 7-8 hours to reach the simmer point. High: 3-4 hours to reach the simmer point.

That varies by what's inside the slow cooker and also by the appliance's setting and model, the experts say. Most recipes for all-day cooking call for 6 to 8 hours on low. Quality- (and safety-) wise, another 1 to 2 hours in 'keep warm' mode won't mess things up.

How can I increase the flavor of French onion soup? ›

Yet another way to brighten your soup would be by adding lemon juice or by giving it a splash of Worcestershire sauce for some umami. Fresh or dried herbs can also help elevate your French onion soup, with bay leaves, sage, and thyme all being typical additions.

Always Add An Acid To Your Soups

Lemon is arguably even more essential in richer soups like wild mushroom and rice, curried split pea, or even white bean and bacon. This is because the delicate balance of flavor profiles requires that acidic, lemony zing to cut through the fats in the soup.

THE ICONIC FRENCH ONION SOUP!

And yet, the soup itself is made with very few core ingredients: butter, onions, flour and stock/broth. The magic is in the caramelisation of the onions, cooked slowly for at least 40 minutes.

The caramelized onions are what give the soup its rich dark flavor and color, so don't skimp! Use a good quality beef broth. We use Better Than Bouillon to make our beef broth because it's extremely flavorful and contains a decent amount of salt, which seasons the soup well.

Some fresh rosemary or thyme brings a woody, peppery taste to the soup, complementing the umami flavor of the beef stock. With a splash of balsamic vinegar and green onions or fresh basil as a garnish, the canned soup is transformed from a grocery store original into a gourmet dish.

"If your broth is lacking in savory richness, try adding roasted onion, tomato paste, mushrooms, seaweed, soy sauce, or miso. These ingredients add umami flavor and depth to broth," she says.

You can extract a clean, strong broth from a combination of water and several pantry ingredients. It's all about layering powerful flavor-enhancers that you probably already have on hand—bacon, tomato paste, herbs, peppercorns, a Parmesan rind, and, of course, kosher salt.