Actually, scratch that. There’s a time to turn on your oven and dirty a lot of dishes and make a huge mess in the name of a seriously good slice of double chocolate zucchini bread*, or banana bread*, or a s’more* (none of these recipes actually make that much of a mess, by the way), but I’m not sure that time is a 90-degree day in August, that’s for sure. Actually, I’m positive that a 90-degree day in August is not the time because no amount of window opening or ventilation fan-ing will prevent the kitchen from heating up to approximately thedepthsofhell degrees fahrenheit. And you deeeeeeefinitely don’t want to turn on your oven for multiple hours, which the traditional method of caramelized onions calls for. Not unless you also hope to be able to fry an egg on your countertop, that is.
It almost seems cruel that caramelized onions, which typically require an unholy amount of time in the oven, are also the perfect summer food, and nothing rounds out a burger (or a sandwich or a salad or an empty fork) quite like them. They’re soft or crispy – depending on your preference, no judgement – and slightly oily and sweet with not a hint of the bitter funk that raw onions leave behind in your mouth.
I love caramelized onions not only because they taste fantastic, but because they immediately class up even the most pedestrian of picnic food. Supermarket burgers straight off the grill? Add caramelized onions and all of a sudden they feel gourmet. Boring salad getting you down? Throw on some caramelized onions and now it feels like a fancy $19 salad from a brasserie downtown (or wherever you get your fancy overpriced salads).
I hate caramelized onions, on the other hand, because they require so much cooking time. I mean, honestly, the cooking time + the outside heat = deal breaker. I also hate caramelized onions because sometimes, if you don’t cook them just enough at exactly the right temperature, instead of slowly meandering from bitter sharpness into the sweet, succulent depths of caramelization, they just burn. And then you have burnt bitterness and a lot of wasted onions.
That, and about five million other reasons, is why I love my slow cooker. I know slow cookers (aka crockpots) are kind of the epitome of Pinteresting trendiness, but they are so incredibly handy – and not just in the winter. If anything I use my slow cooker more in the summer since it doesn’t heat up the kitchen the way the stove does. And, since it cooks the onions low and slow, you basically have to try to burn them – and even then I’m not sure you’ll succeed. If you like your onions on the crispier side, you’ll see. You’ll cook and cook and cook them and when you’re sure they must be burned beyond recognition, you’ll find them perfectly crisp and just ready to be eaten with your fingers like a chip. Don’t fight that urge.
If, on the other hand, you prefer your caramelized onions soft and succulent, the slow cooker can do that too. Just skip the step where you remove the top and let the onions cook down in their juices until they are deep golden brown and, well, floppy enough to be eaten right off the fork. Don’t fight that urge either.
Stop back on Thursday for a really great non-burger-related way to use these that is perfect for your next picnic!
PS: Who knew I could write so many words about onions?
*But if you happen to live in a place that is not currently blazingly hot, I highly recommend all three of those recipes on behalf of satisfied neighbors, friends, readers, and party guests who had a chance to make and/or taste them over the weekend. I never get tired of hearing your reviews of my recipes, good or bad (but hopefully good!), so if you make these, or any of the recipes from this site, please send me a picture (acleanbake@gmail.com) or post them on social media with the hashtag #acleanbake, so I can see!
Updated to add: A few readers have asked what size and model slow cooker that I used for this, because it has some bearing on cooking time. This 4-quart model is the one I use.
Slow Cooker Caramelized Onions
gluten free, grain free, sugar free, paleo-friendly, vegan, low carb
Ingredients
- 2 lb white or sweet onions, shallots also work well
- 2 Tablespoons extra virgin olive oil, or other good quality oil of choice
- 1 Tablespoon coarse sea salt or 1 teaspoon table salt, or to taste
Instructions
- Peel your onions and then cut them in half, then into roughly 1/4" slices.
- In the bowl of your slow cooker, toss together the onions and oil to coat, then add the salt and toss again to combine.
- Cook 8 hours on the low setting with the cover on, then remove the cover and continue to cook an additional 1-2 hours. Once the onions reach a deep amber color, they are done.
Notes
This is the slow cooker I used for this recipe. It has a 4-quart capacity. If your device is significantly smaller, you might want to make a half batch of this recipe, or cook it in two batches.
If you want our onions to be crispy, remove the cover after 5-6 hours.
If you prefer a set it and forget it method, you can leave the lid on for the full 10 hours, but your onions may not caramelize as deeply. You'll also have a bunch of cooking liquid (onion broth?) that you can simply discard.
Store leftovers in an airtight container in the fridge for up to a week.
Julia says
I’m constantly amazed at what can be made in a slow cooker and had no idea you could caramelize onions in one! I, too, adore putting caramelized onions on just about anything and don’t have the patience to hover over the stove to make them in the frequency that I want them. I’m loving this set it and forget it method!
Nora (A Clean Bake) says
Right!? Me too! Doesn’t this open up a whole new world of non-soup or -stew ideas??
Candace @ The Wheatless Kitchen says
Love this! I am totally making my caramelized onions this way next time!
Nora (A Clean Bake) says
Awesome! I hope it is a big time saver for you!
Medha @ Whisk & Shout says
These look fabulous! Love the rich flavors 🙂
Nora (A Clean Bake) says
Thanks!!
Taylor says
+1 on the slow cooker love! I love mine! Sadly I haven’t had it out in awhile and that needs to change…when I make my caramelized onions next time I’m definitely trying them out this way!
Nora (A Clean Bake) says
Oh man, bust that thing out! It is SO great in the summer!!
Lynn | The Road to Honey says
This is absolutely brilliant Nora. I love caramelized onions as they always add more depth to a dish and, as you point out, are a sure fire way to add elegance to any meal. I love that you can make them in a slow cooker. I foresee caramelized onions showing up on my menus more often now. 🙂
Nora (A Clean Bake) says
Thanks, Lynn! I hope you get to eat more caramelized onions from now on! 🙂
Shikha @ Shikha la mode says
Yummm! I always love caramelized onions but have little patience to make them. Slow cooking I think is best!
Nora (A Clean Bake) says
I am SO with you!
Traci | Vanilla And Bean says
Genius.
So I just got a big bag of Walla Walla Sweet Onions from a friend who lives in Eastern Washington and I’m thinking all things onion right now, so this is perfect timing! Who knew?! I’m wondering if I can freeze them after I cook em’ up in the slow cooker…. hummm. Perfection on burgers? Yes please… and oh so much more! Thank you for this Nora!
Nora (A Clean Bake) says
Hey, talk about perfect timing!! Also you read my mind on the freezing thing: I was wondering the same thing. From my experience with similar foods, you probably can freeze them and they’ll be just fine, but I have never tried it. If you do, let me know!
Monica says
Yum! The slow cooker really is a magical thing, huh? Gosh, now you’ve got me craving some caramelized onions as a part of my next meal (:
Nora (A Clean Bake) says
Yes it is a total magic machine! Especially because it makes the magical caramelized onions 🙂
Chrissa - Physical Kitchness says
Hi there! I featured this recipe in my fall recipe round up post today at http://physicalkitchness.com/healthy-paleo-fall-recipes/
Thank you for the inspiration!Â
Nora (A Clean Bake) says
Hi Chrissa! Thanks for including this recipe! I look forward to checking out the article.
Madelaine says
Thank you for sharing your knowledge and experience. I have been searching for ideas to tastefully use the shredded chicken I keep as a staple in the refrigerator. I have been developing ways to keep my weight off and am doing a paleo/weight watchers combo. I made this recipe and cut up shallots using my cast-iron pan to cook up shallots because I didn’t want to wait ten hours. Your recipe is delicious and I am excited to cook up onions in my slow cooker to have on hand. I am having some or breakfast and will definitely do this recipe again. Will probably top with scallions and cilantro and wrap in lettuce.
Nora (A Clean Bake) says
That sounds wonderful! I also have a whole post of ideas for using shredded chicken here: https://acleanbake.com/slow-cooker-shredded-chicken/
Susan says
By all means don’t throw out the “onion broth!” Use it in your next savory recipe instead of water, or add to soups, gravies, broths. Delicious!
Nora (A Clean Bake) says
Good point!