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Cuisinart CSO-300 Combo Steam + Convection Oven review: Versatile cooking for expensive tastes

Does this $299 toaster oven live up to the price? Our team weighs in.

Ry Crist Senior Editor / Reviews - Labs
Originally hailing from Troy, Ohio, Ry Crist is a writer, a text-based adventure connoisseur, a lover of terrible movies and an enthusiastic yet mediocre cook. A CNET editor since 2013, Ry's beats include smart home tech, lighting, appliances, broadband and home networking.
Expertise Smart home technology | Wireless connectivity Credentials
  • 10 years product testing experience with the CNET Home team
Ry Crist
10 min read

The kitchen is one of the most upgradable rooms of the house, and Cuisinart would love for you to consider upgrading your toaster oven. The company's top offering, the sleek CSO-300 Combo Steam + Convection Oven, promises to bring the power of steam to your countertop, transforming your standard toaster oven into a more multidimensional cooking contraption. But that expanded functionality comes at a price -- $299, to be exact. If you think $299 is a lot to spend on a toaster oven, you'd be correct, but Cuisinart would argue that the CSO-300 isn't just a toaster oven, and they'd be correct, too. You'll never be able to steam cook a passable rice pilaf from scratch in a standard toaster oven the way you can in the CSO-300.


Cuisinart CSO-300 Combo Steam + Convection Oven

The Good

With multiple steam cooking settings, the <b>CSO-300</b> successfully expands the functionality of the common toaster oven, and it sports a luxurious, easy-to-use interface, as well.

The Bad

At $299, that new steam functionality doesn’t come cheap. On more traditional settings like toasting and broiling, the CSO-300 couldn’t consistently beat the less expensive competition, and when it did, it usually wasn’t by much.

The Bottom Line

Creative home chefs looking for a powerful, versatile alternative to their full-size oven should give the CSO-300 first consideration, but those just looking for something to heat up Pop-Tarts and Red Barons should stick with something less expensive.

Personally, I'm not sure that rice pilaf gets me excited enough to want to spend $300. That said, if you've already decided that you want to splurge on a high-end toaster oven, then you've certainly got a few good-looking options. Some of these, like the Breville Smart Oven, will whip up bubbly pizza and golden-brown bagels just as well as the CSO-300 does, if not better. However, none of them can match Cuisinart's steam functionality, and for that reason alone, the CSO-300 is my high-end toaster oven of choice.

Read more: The best toaster oven is the one you'll hate the least

Colin West McDonald/CNET

With its hefty price tag, the CSO-300 sets a high bar for itself when it comes to appearances. Given the money you'll have to spend to own one, you're naturally going to expect it to be one of the best-looking, most solidly constructed toaster ovens available. Fortunately, Cuisinart passes the test, as the CSO-300 is about as beautiful and well-built as kitchen appliances get. Its vivid blue LCD screen, brushed stainless-steel exterior, and illuminated dial all give it a classy, high-end sheen that no competitor can quite match. On looks alone, it was our unanimous favorite.

Read moreBest toaster ovens of 2019  

It feels like a quality piece of hardware, too. There's no rattling or creaking when you open and shut the door. The dial offers smooth, reassuring clicks as you turn it from option to option. The plastic 1.4-liter water reservoir doesn't feel flimsy when you take it out and put it back in. This will be something of a luxury purchase for most shoppers, and Cuisinart seems very aware of the fact, since the CSO-300 feels appropriately luxurious.

Cooking with the Cuisinart CSO-300 Steam + Convection Oven (pictures)

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Using the CSO-300 is nearly effortless. The knob presents you with a semicircular array of nine cooking modes, each one with its own icon and default settings. It's a surprisingly intuitive machine given its expansive functionality, and much easier to work with than toaster ovens that use multiple knobs and buttons. The CSO-300 will even automatically detect how warm the oven is at the start and adjust the cooking time accordingly. If your roommate made toast just before you and the oven is still warm, then your toast won't take quite as long.

No matter what mode you use, the CSO-300 will work with the timer, automatically killing the heat as soon as it reaches zero. There's no way to leave it on indefinitely, which is a reassuring safety feature in case you ever forget that you're using it. You can set the timer for up to two hours, and if you need to cook for longer than that, you can always add more time midcycle.

The CSO-300 was a steady enough performer in our basic testing, but it failed to truly distinguish itself from the competition. That's where its steam power comes in, because the CSO-300 can cook things that no other toaster oven can, things like rice, fresh doughnuts, and delicate cuts of fish. If you take a look in the recipe book that comes packaged with the CSO-300, you'll find recipes for dishes like homemade soft pretzels, steamed pork buns, and even an indoor clambake. The CSO-300's versatility is the ace up its sleeve.


The CSO-300 will cook a pot of rice to perfection in about 30 minutes.

Ry Crist/CNET

In our tests, the steam cooking modes worked perfectly. Simply pull out the reservoir, unscrew the cap, fill it with water, and return it to the base -- just like that, you're ready to cook with steam. With four separate steam modes, each of which can be adjusted and customized, that's a lot of new functionality to play with. There's the previously described steam baking mode, ideal for roast chicken. Steam broil mode will let you cook foods like meat and veggies at a high temperature without anything getting too dry. Steam mode is great for basic, lower-temperature steaming, and super steam mode is what you'll want to use to cook rice.

I found that the CSO-300 will, in fact, cook a great pot of rice. The instructions recommends steaming your rice for 20 to 25 minutes, but the ideal time was more like 30 to 35 minutes. Still, I was impressed. For meats and other, more complicated dishes, you can even add a little bit of wine or any other liquid to the baking pan, then steam the flavor directly into your meal.


The CSO-300's steam settings can also help resuscitate last night's dinner.

Ry Crist/CNET

The steam settings are also ideal for reheating leftovers, especially when there's sauce involved. I brought in some homemade manicotti from the night before. Using the CSO-300, I was able to reheat it in less than 15 minutes, and with pretty remarkable results. The sauce was the perfect consistency and the noodles were nice and tender, not at all crunchy and overdone like they might have turned out in a standard toaster oven, and not soggy either, as you'd get in a microwave. Even the delicate ricotta filling came out tasting fresh. I also used the steam settings to reheat some leftover frozen pizza, and honestly thought that it came out tasting even better than the first time around.

Comparative performance
If you're going to buy a high-end toaster oven, you want to know that it's going to cook the foods you love to satisfaction, and in our expansive run of tests, the CSO-300 did an admirably steady job versus the competition. Taste is a subjective thing, making it difficult to say that it cooks food any better or worse than another model, but in terms of doneness and consistency, the CSO-300 hit its marks time and time again.

Ry Crist/CNET

The first thing that you would expect a toaster oven to be able to handle is toast. Surprisingly, not every model that we tested made toast as effortlessly as you might imagine (I'm guessing you can spot the problem child in the chart above.) Fortunately, the CSO-300 didn't give us any real trouble here. It offers you seven different darkness settings, and for the most part, all seven accurately hit the mark. The one snag: consistency was a problem when starting from a hot oven versus starting from a cold one. The timer adjusted automatically when the oven was hot to start with, shortening the cooking time, as it's supposed to. However, sometimes it seemed to shorten it too much, causing the toast to undercook just a little. This wasn't an issue that we saw in other, longer tests, which makes sense -- the short cook time of toast makes it more susceptible to this kind of variance. In the end, it's a minor issue, and at any rate, we're happy that the CSO-300 errs on the side of undercooking and not overcooking. No one likes burnt toast.

Ry Crist/CNET

Next, we broke out the cookie dough, cooking multiple batches in each oven according to the product's instructions. Aside from making our lab smell incredible for a few hours, we learned that toaster-oven-baked cookies just aren't quite as good as ones baked in a full-size oven, so cookie enthusiasts might want to temper their expectations a bit. In most models, including the CSO-300, the dough tended to crisp up on the outside a little too quickly, leading to an uneven bake and a rather mediocre cookie. This isn't surprising, given how much closer to the actual heating element the cookies were, as opposed to ones baked in a full-size oven.

Interestingly enough, the one exception here was the Panasonic FlashXpress, the only non-convection toaster oven we tested. Cookies baked in the FlashXpress seemed to come out more evenly baked than the others, and when we put our wares out for a blind taste test, our tasters agreed, naming the Panasonic's cookies the best of the bunch.

Ry Crist/CNET

Things got interesting when we started testing frozen pizza. The Frigidaire Professional, which had already disappointed us with its propensity for burning toast, produced undercooked, underwhelming pizzas when we cooked them according to the product's specifications (it did a little better when we used its own frozen pizza setting). With the Panasonic unable to fit anything larger than an individual-size pizza, we were left with a battle between our two heavyweights, the CSO-300 and its top competitor, the Breville Smart Oven.

Ry Crist/CNET

Both performed very well, producing tasty pizzas with each run. Some of our tasters preferred the evenly baked pizza of the CSO-300, while others enjoyed the more well-done, borderline burnt cheese on the Breville's pie. In the end, I'm calling it a draw between the two, although for my own personal tastes, the CSO-300's pizza is the one I'd want to eat. That said, pizza lovers shouldn't rule the Panasonic FlashXpress out too quickly. True, it's a bit limited in terms of size, but it still cooked an individual-size pizza just as well as the CSO-300 and the Breville cooked full-size ones.

Ry Crist/CNET

The CSO-300 continued to duke it out with the Breville as our testing turned to roasting chicken. We were actually impressed with almost all of the chicken that was cooked, but it was the CSO-300 and the Breville that maintained a consistent edge in our taste tests, if only a slight one.

Using the CSO-300's steam bake setting, we were able to get a crispier, tastier skin than we could with the other ovens. The chicken was moist, too, although not quite as moist as the Breville, which won the majority of our taste testers' votes in the end. This was a little bit surprising, as the chicken test was the first time I had reason to use the CSO-300's steam baking setting, with crisp, moist chicken being its calling card. Even the icon for the steam bake setting is a roast chicken. To be fair, the CSO-300's chicken was indeed excellent, but still, you have to be impressed with the Breville -- when it came to keeping chicken moist, it outperformed a steam oven.

Colin West McDonald/CNET

I love a good burger, but I'm not sure I'll ever crave one cooked in a toaster oven, not even one cooked in a toaster oven that costs $299. Broiling burgers in the CSO-300 cooked the meat efficiently, but perhaps too evenly, failing to give us much char on the outside at all. The texture of the meat was chewy and a little dry, and left us wishing we were testing patio grills out, instead. Switching over to the CSO-300's steam broiling mode yielded better results, with the meat coming out a fair deal juicier, but as burgers go, the results were still far from exceptional.

In fairness, none of the toaster ovens impressed us with their performance in the burger test. Only the Breville managed to get any kind of char on the meat, but that didn't win it many extra votes in our taste test, where our guinea pigs had a hard time calling any of the burgers a winner. The real takeaway might in fact be that anyone planning on upgrading their toaster oven in order to broil a better burger might want to think twice.

Given that it has a 1.4-liter water reservoir attached to it, you might expect that the CSO-300 would be a higher-maintenance toaster oven than other units -- and you'd be right, to an extent. Like a coffeemaker, you'll have to decalcify the machine at least once a year to remove harmful calcium deposits. Fortunately, this isn't actually all that much work; you'll just need to run a 75-minute steam cycle using distilled vinegar. Owners who use their oven more frequently will want to decalcify on a more regular basis.

Cleaning the oven is rather easy. A tray at the bottom catches drips and crumbs, then slides out easily for quick cleanup. For heavier messes, you can always run a 30-minute steam cycle to loosen things up, then wipe the interior clean with a damp cloth.

Colin West McDonald/CNET

Service and support
The CSO-300 comes with a generous three-year limited warranty from defects in materials and workmanship. Every other toaster oven that we tested came with a standard one-year warranty, even the comparably priced Breville Smart Oven, so this was definitely a strong point for Cuisinart. A three-year warranty speaks to their confidence in the quality of the CSO-300's build.

The CSO-300 comes packaged with instructions for cleaning, maintenance, and decalcification, as well as a very brief troubleshooting section. The Cuisinart Web site doesn't feature much more in the way of troubleshooting or frequently asked questions, although it does provide PDF copies of the product manuals. You can also submit support questions through an online form, or call toll-free 7 days a week at 1-800-726-0190.

Colin West McDonald/CNET

All things considered, the CSO-300 was one of the most impressive toaster ovens that we tested, though I wouldn't say that it dominated the competition. A better description would be to say that it always kept up with the competition -- if another model outperformed it in a certain area, it was never by very much. What's more, the CSO-300 didn't show us any specific weak areas relative to other models, and never finished at the bottom of any of our tests. As conventional toaster ovens go, it's about as well-rounded as they come. Throw in the CSO-300's steam cooking settings, all of which tested quite well in our performance tests, and you've got one of the most versatile countertop ovens currently available.

Does its versatility alone justify the $299 price tag? For most shoppers, I'm not convinced that it does, but once you factor in the luxurious build-quality, the ease of use, and the attractive-looking design, I think you can begin to see why it would be an appealing and justifiable purchase for many home chefs, especially ones looking to make use of the specific advantages offered by steam-powered cooking. If this sounds like you, I say buy it with confidence. Otherwise, I'd recommend sacrificing a little bit of that versatility for the sake of your wallet, and sticking with a much more affordable but still impressive model, like the Panasonic FlashXpress.


Cuisinart CSO-300 Combo Steam + Convection Oven

Score Breakdown

Performance 7Usability 9Features 8Maintenance 7