HOME > Chowhound > Home Cooking >


Carmelized onions

When making carmelized onions is it customary to add sugar? Do the onions get sweet without adding sugar.

  1. Click to Upload a photo (10 MB limit)
  1. I don't add sugar. I cook them at lower heat -- you need to be patient! -- and they get nice and sweet.

    1. I do not add sugar. The caramelization adds all the flavour I need. Butter and/or oil in a medium hot oven (don't move the onions around too much) or on medium low on the stove top until they are golden brown.

      1. I don't add sugar. I generally use the yellow onions since they are sweeter (higher sugar content (glucose?)) and just let them cook under low heat...

        1. I don't add sugar, just low heat and patience, patience, patience. I know that some people do add a teaspoon or two of sugar (or Splenda for that matter) but it generally isn't necessary.

          1. Previous posters cite the patience required, but just to quantify this --- we're talking perhaps 40 minutes for the best results. Well worth it.

            1. I'm another one who doesn't add sugar. I consider it cheating. Actually, I don't do it because it adds a strange brown coating to onions and encourages undercooking. And I love the natural sweetness of well-caramelized onions - I would hate to cover up that taste with table sugar.

              If the 30 or 40 minutes seem too long, try the crockpot method of making caramelized onions. Do this ahead of time, then freeze portions in small baggies for use when you're making something that needs some caramelized onions (in my house, that's everything except oatmeal and brownies). You might have to saute the onions a few minutes more, but it's a great time saver!


              1. For small quantities I like Julie Sahni's "brown-frying" technique--slice thin and cook, stirring constantly, in a little oil over medium-high heat (I use a small wok). Goes pretty quickly if you're only doing an onion or two. No sugar.

                1. I'm curious about everyone's carmelized onions (taste, consistency) because I cook mine much longer. I cook them on medium for about 5 minutes, then turn the flame to low, cover, stir every 20 to 30 minutes for about 2 hours. Clearly much longer than most of the folks who have posted on this thread. Does anyone else cook them as long as I do?

                  5 Replies
                  1. re: debbiel

                    I think I cook mine for 40 minutes max if making French Onion Soup - recipe calls for golden. But, if I'm making an onion confit, it could be more than an hour.

                    1. re: debbiel

                      I am now a convert to JoanN's in-the-oven version. It's much like you do, tossing every 30 minutes for 2-3 hours of elapsed time. I do the onions, the laundry and the bathrooms all at the same time. Standing at the stove stirring for 30+ minutes is not for me.

                      1. re: orangewasabi

                        I can't locate the in-the-oven version. Can you help out? Thanks

                        1. re: nance

                          I found it here

                          Read the posts immediately before and after for additional information.

                      2. re: debbiel

                        I cook them longer than many others, generally an hour to hour and a half at times but it depends on the amount of onions in the pan. I often do a massive amount of onions - about five very, very large ones.

                      3. Yes, it seems to take forever to cook and then go from perfect to burnt in a matter of seconds! I'm curious about the crockpot method, can someone please explain?

                        2 Replies
                        1. re: harryharry

                          The crockpot method works fine, for me. Just fill the thing up to the top, put a stick (or a little less)of butter on top, turn it on and go to bed. When you get up it should be about done. 7-10 hrs. Some people think they come out a little moist. Cook them longer.
                          I think they come out great. It's just so easy I can't even try another way.
                          There was a big thread on this awhile back. You should try to find it.

                          1. re: Bobfrmia

                            I was a skeptic about this but it turns out perfectly. No more stirring on the stove.

                        2. I never add sugar, but sometimes a splash of sherry, port, madiera, etc.

                          1. I am with you, Debbie: learned this from Julia Child's method for French Onion Soup then slowed it down and added about an hour...so worth it!

                            1 Reply
                            1. re: LJS

                              Okay, so I'm not alone (I need to stop doubting myself so much!). I don't know if this makes a difference, but I don't make them for soup. I've never actually made French onion soup. We use them for sandwiches, pizzas, and appetizers (crostini, e.g.).

                              Time got away from me today. I just turned the oven off, and I think they cooked for about 2 hours 45 minutes. They are incredibly tasty.

                            2. I am firmly a 40-60 minute carmelizer. But I had a slew of time to kill this weekend and made some onion soup. I was intrigued by the posts last week on Keller's 5-hour method. I carmelized for 3 hours. The onions had a consistency like butter, the flavor was very intense and it was a different experience.

                              Would I do this all the time. Nope. Older daughter asked me to make her onion soup for her visit on Sunday night. Will gladly comply but she will probably get the 1-hour versus 3- hour version. BTW, absolutely no sugar in the camelizing function.

                              1. What temp do you set your oven?

                                As a practical matter, I would think that virtually all the carmelized onions we eat at restaurants are done in ovens rather than a saute pan.

                                1 Reply
                                1. re: Den

                                  oven at 350.

                                  imagine you're right about the restaurant onions too, Den.

                                2. Now that we've reached consensus about not adding sugar, I wonder how much of a difference the pan makes? Non-stick, or not?

                                  1. Since I'm normally sauteeing in butter I do not give a lot of thought to the pan.

                                    This past weekend I used a large farberware soup pot. With a stcik of butter and 6 pounds of sliced onions, the butter kept it going until the liquid released from the onions and then, in hour 3, when the liquid was evaporated, I moved them every 5-10 minutes. Very little sticking problem, but i needed to pay more attention in hour 3.

                                    On the 40-60 minute version I use a non-stick pan, because it's my favorite.

                                    1. If you need to carmelize a lot of onion, I read a tip once to bake the whole onions in the oven for 1 hour first at a low heat. I don't remember what the setting was or where I read this tip, but if I were to do it again, I'd probably do 275(?). After baking for an hour, you take the onions out and slice them. They apparently start to release their sweetness during oven-time and it takes less time to carmelize them after that. I did this the last time I made French onion soup, and it turned out better than I could have imagined.

                                      1. How much butter/oil do people use? Enough to coat/more/less? How would you measure it if you're doing it in the oven instead of on top (or would you melt the butter beforehand)? I forsee some experimentation in my future...

                                        3 Replies
                                        1. re: pamalamb

                                          in the oven for 3lbs I used 1/4 a stick of butter, just dolloped around.

                                          1. re: pamalamb

                                            I used 2 TB butter and a little olive oil for about 3 lbs yesterday, done on the stove top, using enameled cast iron buffet pan.

                                            1. re: pamalamb

                                              I used a stick (1/4 pound) of unsalted for 6# of onions last weekend.

                                            2. I use olive oil only - just barely enough (maybe a tsp or two per onion?). I keep a constant eye on the onions and stir frequently - I'd add more oil if I had to ignore them for a bit. If the onions get really dry, I add a splash of wine or broth.


                                              1. I used 3 TBls for 4 onions ( 2 brown and 2 sweet onions) it tool 40 min in a cast iron pan to carmelize, but they were fabulous. I added some homemade beef stock and had onion soup. It was very rich!

                                                1. I like to caramelize them in the bottom of a baking pan under a brisket for about 8 hours.

                                                  1. Another trick is using a Le Creuset, it makes for the BEST Caramelized Onions...


                                                    1 Reply
                                                    1. re: Dommy

                                                      Good to know. I'll try that next time. I've been using a very large skillet.