Does French Onion Soup Contain Alcohol?
French onion soup is a quintessential dish — a powerhouse of flavor and texture that is surprisingly amenable to personalization. You can replace the broth with beef consommé, as Alton Brown does, to add a deeper, beefier flavor to your soup. You can also swap out your French onion soup's Gruyére or mix it with mozzarella or provolone for the ultimate gooey cheese topping. You can also decide whether or not the dish should include alcohol.
If you weren't aware, a classic, simple French onion soup typically contains alcohol, especially when served at a restaurant. The booze is added after the onions are well-caramelized, helping to deglaze the pan and imparting flavor to the stock added later.
For a tried-and-true method, cook the onions with butter and aromatics over medium heat for about 30 minutes until fully caramelized. Then, add your alcohol and broth, bring the mixture to a boil, lower the heat, and let it simmer for 30 minutes to an hour. Skim off any foam, and prepare the oven for the final cheese-melting stage. Most of the alcohol will have burned off by this point, though it's important to note that alcohol never fully cooks out of food.
Alcohol to use in French onion soup, and how to substitute it
If you decide to make your French onion soup with alcohol, there are plenty of options depending on what you have on hand and the flavors you'd like to highlight. If you're using more broth, you can opt out of using wine and simply deglaze the pan with a couple of tablespoons of brandy or sherry. Alternatively, you can go the other route, and use less stock and incorporate more wine.
Anthony Bourdain's recipe for French onion soup calls for equal parts port wine and balsamic vinegar, while Julia Child uses white wine as the primary source of alcohol, followed by a dash of cognac toward the end of the cooking process. As you can see, the combinations are numerous and depend largely on personal preference.
For those looking to forgo alcohol altogether, there are several alternatives. A small amount of white wine vinegar or balsamic vinegar can replace wine, but the simplest solution is to deglaze your caramelized onions with beef stock and flour before cooking it down and finishing with cheese and bread.