When I think of luxury foods, I think of things that are expensive enough that I'd buy them only in very small quantities, as an occasional indulgence, if at all. White truffles? No thanks. Caviar? Lemme grab a really small spoon. Cured fish like lox and sable? I'll get three-quarters of a pound of each—oh wait, that's $17.99 per quarter pound? I'll just get a quarter pound of the lox, thanks.
That's why I love gravlax, Scandinavia's dill-flavored cured salmon. It seems like just as much of a treat as lox, but, because it's so easy to make, there's no reason to pay for the cost of someone else's labor—just make it yourself. For the price of a nice fresh fillet of salmon and a very short, two- or three-day wait, you can serve a beautiful spread of hand-sliced gravlax as an hors d'oeuvre or light appetizer. Plus, because you're making it yourself, you can customize its flavor with the aromatics of your choice.
The whole process is ridiculously easy, which is cool, because gravlax continues to be one of those dishes that manage to impress people. (No joke: The hardest thing about making your own gravlax is slicing it.) It's so easy, in fact, that testing this recipe was as simple as figuring out the best ratio of salt to sugar in the cure, plus a couple other variables. After that, I was done.
Unearthing Gravlax: What Is It?
Very simply, gravlax is salmon that's been cured with salt and sugar and infused with the flavor of fresh dill and sometimes other aromatics and spices. Unlike the lox that we eat on bagels, gravlax is not cold-smoked. The grav part of its name comes from a Scandinavian word for "to dig" (it shares a root with our word "grave"), and the lax part just means "salmon." In essence, the name is telling you that it's "buried salmon," which is how gravlax was apparently originally made: buried in sand on the beach until it was fermented. Sometimes it was wrapped in birch bark and pine needles before it was buried.
Today, the only burying that goes on is in heaps of dill and the dry brine* of sugar and salt, and there's not really any significant fermentation to speak of. There are no funky flavors to develop a taste for, just the clean, mildly salty flavor of lightly cured salmon and dill.
*For the food geeks like me out there, you might be interested to learn that there's a wet-brined counterpart to gravlax called lenrimmad lax.
The Dry-Brine Ratio
Because gravlax is an inherently simple preparation, the biggest question was merely what ratio of salt to sugar to use in the dry brine. Existing recipes are all over the place on this one, with some using more sugar than salt and others calling for the opposite.
On a technical level, what both the salt and sugar do is draw moisture out of the fish through osmosis. This decreases the moisture level of the fish, which in turn makes it less hospitable to microbial life. The salt, meanwhile, also helps ward off bacteria that would otherwise hasten spoilage. This extends the edible life of the salmon, but only for a short amount of time—gravlax is not cured in any long-term sense of the word.
Ultimately, the ratio of salt to sugar is a question of personal taste. If you prefer a sweeter flavor, more sugar should go into your cure. If you have a more savory-leaning palate, you'll want to go heavier on the salt. That said, I still wanted to do side-by-side tests, have my colleagues taste them, and see if there was a consensus or not.
I whipped up three batches of gravlax, one with a 1:1.5 ratio of salt to sugar, one with equal amounts salt and sugar, and one with a 1:1.5 ratio of sugar to salt. My ratios were all based on weight, since volume measurements of salt and sugar can be misleading—not only do salt and sugar have significantly different weights by volume, but different brands of salt can weigh more or less as well.
The differences were easy to detect, and exactly as you'd expect: The sugar-heavy cure produced a sweet-tasting gravlax with very little saltiness; the 1:1 cure was the blandest, neither sweet nor salty; and the salt-heavy cure produced gravlax with a pleasant level of saltiness that was rounded out by a very subtle sweetness. The saltier cure also helped firm the salmon more, while the sweeter gravlax retained more of the salmon's sashimi-like raw-fish texture.
Interestingly, my Serious Eats colleagues were unanimous in their preference for the salt-heavy cure, which was also the one I preferred. Unless you're certain you want a sweeter flavor, I'd recommend leaning toward that salt-heavy ratio, since it seems to be the crowd favorite.
Cure Time and Shelf Life
One of the important things to understand is that gravlax is lightly cured, so the fish's shelf life is extended only by a little, not a lot. Gravlax will go bad on you. Exactly how long it lasts will depend on just how pristine the fish was when you bought it (no matter what, it should be sushi-grade—make sure to tell your fishmonger that you're planning on eating it raw), as well as how it has been stored and handled. On average, my samples started smelling a little fishy after about five days or so, not including the curing time itself.
As a general rule of thumb, I'd plan to eat the gravlax within a few days after it's been cured, and stop eating it if you start to detect any off odors.
Beyond the salt and sugar, you have options for other flavors in your gravlax. Dill is essential for the classic gravlax flavor, and white pepper is very common. For those who don't like the pungent taste of white pepper, black pepper works well, too.
Great gravlax is possible with salt, sugar, white pepper, and dill alone. If you want to add even more dimension, spices like caraway seed, coriander seed, and fennel seed are all good options. My recipe includes caraway and coriander, because I love those flavors and think they play well with dill, but there aren't really any right or wrong choices here.
You can also supplement the dill with other herbs, like tarragon or fennel fronds. If you can get your hands on some conifer needles, like Douglas Fir, that might even be a cool throwback to the way they did it in the Middle Ages.
Some people add citrus to the mix. I'd strongly advise against using actual wheels of citrus or juice, which some recipes call for; the acid will "cook" the fish, as it does in a ceviche, toughening the fish's exterior in an unpleasant way. If you want citrus flavor, add zest instead.
It's also common to see alcohol, like aquavit and brandy, in gravlax recipes. I prepared a test using my salt-heavy cure along with a few tablespoons of aquavit (on a half-pound piece of salmon), and found that it didn't significantly alter the flavor or texture of the fish. Some liquors, like brandy, might have a bigger flavor impact, but I'd say if you want to taste caraway—the spice used to flavor aquavit—you're better off just using the spice itself.
If you're eating gravlax the traditional way, you'll want to serve it with hovmästarsås, the mustard-dill sauce typically spooned on top. Most recipes make this as a fairly sweet sauce, with a healthy dose of sugar. Maybe it's because I have a palate that tends toward salty things, but I don't understand why anyone would want to spoon such a candy-like sauce on their fatty cured salmon.
My version, while adhering to the basic sauce in terms of its ingredients—dill, Dijon mustard, white vinegar, sugar, and oil—is much less sweet. I add only enough sugar to round out the sharp edges of the vinegar and mustard in the sauce, but not so much as to make it overtly sweet. The vinegar and Dijon mustard shine through, cutting the richness of the salmon while adding a blast of fresh flavors.
Step by Step
I start by giving the skin-on salmon a 10-minute bath in salted water. (I just salt it to taste, then drop the fish in.) This isn't a required step, but it can help wash off any juices on the surface of the fish that might develop off aromas prematurely. I pat it dry when I take it out of the brine.
Then I rub half my cure mixture onto the skin side of the fillet.
It may not stick to the skin all that well, but do your best to get even coverage, and it'll be fine.
Next, I arrange some big tufts of dill in the bottom of a baking dish, and set the salmon on the dill, skin side down. I rub the remainder of the cure all over the top and sides of the fillet, sprinkling any extra cure all over, and then pack more dill on top of that.
I cover the fish in plastic, then set something on top of it to weigh it down. This could be a smaller baking dish, or a flat plate roughly the size of the salmon, with some heavier things, like cans of beans, on top. This will help press even more moisture out of the fish as it cures.
I put the whole thing in the fridge and let it cure for one day. Then I flip the fish over so that it's skin side up, wrap it with fresh plastic and return the weight to the top, and let it go one to two days longer. Two days will give you a slightly lighter cure, while three days will cause the fish to become just a tiny bit firmer.
As I mentioned above, carving gravlax is arguably the only hard thing about it. You absolutely must have a sharp knife. Sorta sharp just won't cut it, literally. Gravlax is delicate and will tear under the force of a dull knife. Ideally, you should reach for a thin slicing knife, since the reduced surface area of the thin blade means there's less of it for the salmon to stick to as you slice.
If you feel comfortable with the sharpness of your knife and your skills in wielding it, you can cut beautiful wide slices from the entire fillet. Try to work on a bias so that the slices don't come out as skinny little strips.
If you don't feel that comfortable, you may find it easier to divide the fillet in half lengthwise along its natural division, then cut each fillet half into smaller slices.
Some folks are bothered by the brown-colored blood line that runs along the middle of the fillet on the skin side. You can get rid of it by sliding your knife between the pink salmon flesh and the skin, trimming off the blood line as you go.
Then you can cut your skinned, blood-line-free portion into slices.
You can eat the gravlax alone, or drape the slices on pieces of pumpernickel.
Then spoon some of that sauce on top. Now tell me that's not luxurious!