We spend a lot of time here at Serious Eats reinventing recipes. Instead of adhering to the received wisdom, we try to push beyond that, seeking methods and techniques that get us to an even better version of the dish than most others have. Whether sneaking gelled stock into meatballs, sushi rice into arancini, or fish sauce to, well, just about everything, Kenji and I have a ton of fun thinking outside the...um...pot.
There's a saying, though, that's important for us to remember as we attempt to rethink recipes: If it ain't broke, don't fix it. Overcomplicating a recipe just for the sake of it does neither you nor us any favors. I had to embrace this mantra as I worked on this foolproof cheese fondue recipe. I tried all sorts of tricks in my tests, from slipping in cream of tartar (to bump of tartaric acid levels—more on that below) to using gelatin as an emulsifier. Once all the dust had settled, though, what I found was that a very basic and classic method worked the best.
This is good news! It means fondue really is easy to make without any extra steps. But that doesn't mean I don't have tips for you—because fondue sure can go wrong if you're not careful.
The Wine and its Acid
Wine is one of fondue's few essential ingredients, and its importance goes beyond just flavor: the natural tartaric acid in wine prevents the cheese's casein proteins from clumping together and turning the fondue into a stringy, broken mess. This is why I tried adding even more tartaric acid to one of my test batches in the form of cream of tartar, aka potassium bitartrate, which dissolves into tartaric acid and potassium ions. It seemed like a good idea, but I didn't notice a significant difference, so I ended up leaving it out of my recipe.
Citric acid has the same effect as tartaric acid, so I add some fresh lemon juice to my fondue. It's a happy little accident that lemon juice helps the fondue's stability, because, just like wine, it also tastes great with the cheese, its brightness balancing all that rich dairy fat. (In fact, citric acid was one of the original key ingredients in the processed cheese—like Kraft Singles or Velveeta—that melts so well; today sodium citrate, a sodium salt of citric acid, is more commonly used.)
Because of the importance of the wine's tartaric acid in forming a stable fondue, many sources stress that you should use a tart wine (the more tart it is, the more tartaric acid, naturally). I tested several types of dry—read: not sweet—white wine in this recipe to see just how critical wine choice is.
I started with different quality levels of pinot grigio, including some cheap boxed domestic stuff, a bottle of cheap Italian stuff, and a bottle of slightly more expensive Italian stuff. Price isn't always a reliable measure of wine quality, but I tasted each and felt that in this case it worked as an indicator of quality. And while none of these were Swiss—the country of origin of fondue—I figured that the light, crisp Italian ones, which come from the Alpine north, were close enough to be good options that are readily available here. I also tested some buttery, oaky Chardonnays, which, in theory, should not have performed as well.
In practice, I found little difference in the wines once they were cooked into the fondue. Quality differences, which were notable when tasted straight, vanished once cooked and combined with cheese and other ingredients. And while there may be some truth to the idea that it's a safer choice to go for the crispest, most tart white wine possible, I was able to successfully make fondue with all the wines, including the less acidic buttery Chards. Even the oakiness, which I feared would be a distracting flavor in the final fondue, ended up not being an issue for myself or any of the tasters.
The takeaway is that, while a very tart, crisp white may be, on a technical level, the best choice, you can pretty much get away with using whatever cheap dry white you have available. Pouring good, pricey wine into fondue is basically a waste of money.
As I mentioned, fondue comes from Switzerland, and so the cheeses most commonly used to make it are Swiss ones like Emmentaler and Gruyère. I decided to stick to tradition here—venturing outside the classics opens up a dizzying world of possibilities.
Taste Emmentaler alone, and I think you'll agree with me that it's a really boring, bland cheese. Gruyère, on the other hand, is full-flavored, just slightly funky, and delicious. It's also more expensive. I made batches with each of these cheeses alone, and also in combination.
Fondue made from just Emmentaler falls flat; there's just none of that good Alpine cheese flavor. Fondue made from Gruyère by itself is delicious, though its funkiness is more pronounced, which sensitive cheese-eaters may find challenging to eat in large amounts. It's also a lot more costly, given the price of the cheese. If you're a fan of Gruyère and willing to pay for a fondue made purely with it, go for it. A good middle ground, of course, is to use a 50-50 blend of the two cheeses, which saves some money, while still delivering a lot of that good Gruyère flavor; that's what my recipe calls for here.
The Big Warning
When I was testing this recipe, I made a series of small batches before settling on a final recipe and then scaling it up. Once scaled up, though, I started having problems: My fondue kept breaking, repeatedly. The worst part was, I couldn't figure out why. I wasn't doing anything out of the ordinary, and everything had worked just fine for me on all of my smaller batches.
My only thought was that my fondue, once scaled up, was somehow getting too hot on the somewhat finicky induction burners we have in the Serious Eats test kitchen. I set up a double boiler by nesting a stainless steel mixing bowl over a pot of simmering water, and repeated my recipe once more. And sure enough, the fondue came out perfect—a tremendous relief for me, because I had no other idea what could have been wrong.
In retrospect it makes sense. The induction burners we have at work don't do low heat well. For the smaller batches, it didn't matter, because the smaller quantity of cheese melted quickly enough that it didn't spend too much time on the heat. But once scaled up, I had to melt a lot more cheese, and inevitably the cheese already in the pot got too hot before the fondue was finished, even at the lowest heat setting on the burner.
In the double boiler, the heat was gentle enough that even with prolonged exposure, the fondue never got hot enough to break. It's a lesson to keep in mind: The key with fondue is to keep the temperature very low once you start adding the cheese. The cheeses in this fondue have a melting point around 150°F; let them get much hotter and their proteins will press into each other, causing the fondue to break. It takes more patience since the cheese will melt more slowly at low heat, but it's the single most important thing I've found to guarantee a nice, even result.
With that in mind, here's how easy it is to make fondue.
The first step, a classic one, is to rub the cooking vessel down with a cut clove of garlic. It helps put some good garlic flavor in the fondue.
Then the wine goes in the pot. I found a ratio of about one cup of wine per pound of cheese worked well.
While the wine is heating, take your grated cheese (a food processor with the grating blade attached makes quick work of it), and toss it with cornstarch to coat. The cornstarch is yet more insurance to keep the fondue from breaking, coating the proteins and fat and preventing them from coalescing. Some recipes call for a flour-based roux, but I found cornstarch to work very well, producing a fondue without any starchiness. Since it's less work than making a roux, it's my preferred way to go.
In case you're curious to see what can happen without a starch, the below photo is a batch I made without any. As you can see, the cheese isn't emulsifying very well with the wine.
Next, add the cornstarch-coated cheese shreds a handful at a time, mixing it into the hot (but not too hot) wine as you go, and waiting until each addition is mostly melted before adding the next one.
Once all the cheese is added, you should have a smooth, even melted-cheese sauce. Now's the time I add the lemon juice. A splash of kirsch is a really nice boozy touch at this point as well.
I season the fondue with salt and white pepper, though black pepper is fine too as long as you don't mind seeing little black flecks in the cheese sauce.
And that's basically it. Set it out with toasted croutons, or lightly blanched vegetables for dipping. A fondue pot helps a lot, since the fondue will thicken and set rapidly as it begins to cool just a little. It's actually a fairly narrow temperature band in which to work. Too hot and it can break, too cool and it will thicken and set. That's pretty much the only tricky thing about fondue.
If your fondue gets too stiff, you can also hit it with another splash of white wine, stirring it in until the fondue has loosened.
So that's really all you need to know to make some great fondue. But now that I've explained the how behind fondue, it's time to address the why. The why is the camaraderie and love that it engenders between people. I mean, just look at how much Max and I are enjoying our little fondue feast. I get warm and tingly just thinking about it.