Slow Cooker French Onion Soup Recipe (2024)

FAQs

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

My personal go-tos include worcestershire sauce, fish sauce, and brandy. Each deepens the flavor of french onion soup. Balsamic vinegar and soy sauce are other great options.

It can be nice to cook the onions beforehand, as the flavour is different to when you put them in raw, but experiment both ways as you may find you prefer one. It can also be good to brown meat to give it some colour, but again, this is not essential.

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.

That's because the low, slow style of cooking lets the flavors simmer together for hours, creating a much richer and more flavorful meal.

Herbs and sources add flavor, aroma, and intensity to the soup broth. You can pick fresh or dried herbs like basil for tomato-based soups or fresh parsley for clear broths. You may also add more spices like turmeric, ground ginger, ground paprika, or nutmeg for a touch of spice and color to your soup broth.

If the heat is too high, the onions will burn. If you don't stir often at beginning and almost constantly toward the end, the onions will burn. If one little bit burns the whole batch needs to be tossed. Otherwise the soup ends up tasting like burnt onion.

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. To maintain the red hue, add a little acid, such as a splash of vinegar or a squeeze of lemon juice.

Tender vegetables

Vegetables such as peas, asparagus and peppers can become a flavorless, mushy mess in a slow cooker. Stick to heartier root vegetables like potatoes, onions, leeks and yams, or wait to add the tender vegetables until the last 30 minutes or so of cooking time.

Lemons are a chicken soup game changer. Why? They brighten up and balance the salty, rich flavors of the dish, and make all of the ingredients come into line. Like a vinaigrette on a salad, the pickle on a burger, and the sour cream in a coffee cake, a squeeze of lemon gives chicken soup a game-changing brightness.

The sweetness of the onions is key to the flavor of the soup, as the onions are slowly cooked until they are caramelized and golden brown, which brings out their natural sweetness and deepens their flavor.

Why is my French onion soup sour? ›

It might be because of the stock or that you used onions that has sour flavor such as white onions.

Stick to the cook time indicated on your recipe

Most slow cooker meals take 8-12 hours on low or 4-6 hours on high, but there are also recipes for slow-cooked meat that take up to 24 hours. If you want to avoid overcooking your dish, follow the given guidelines as closely as possible.

Many slow cooker dishes are just as good the day after, before the flavors have had time to blend together. Due to the nature of a slow cooker, there is no need to stir the food unless it specifically says to in your recipe.

Editor's Tip: Can you overcook soup in a slow cooker? It's a common question—and the short answer is yes. Ingredients like veggies, pasta and rice can get very mushy if left in the slow cooker too long. Many meats will toughen, too.

Fix a bland onion soup by using supermarket broth and mild white onions, tasteless oil for sauteeing, stale plain white bread instead of croutons, and mild white cheese. Start by reducing the broth. Simmering out some water will intensify the flavor of the broth. Once you get it to the right point, add some salt.

Use fresh vegetables, high-quality meats or broth, and fresh herbs to add depth of flavor. Add acidity: A squeeze of lemon or lime juice, a dash of vinegar, or a splash of wine can brighten the flavors of a soup and make it taste more complex.

A squeeze of citrus, a dollop of yogurt or a drizzle of cream, a dusting of cheese or a good chile powder, a sprinkling of some herbs or croutons — all can take a perfectly fine soup into the realm of the delectable. Even a spiral of good olive oil to finish and some coarse sea salt can do wonders.