The Food Lab: How to Pan-Fry Salmon Filets
It's time for another round of The Food Lab. Got a suggestion for an upcoming topic? Email Kenji here, and he'll do his best to answer your queries in a future post. Become a fan of The Food Lab on Facebook or follow it on Twitter for play-by-plays on future kitchen tests and recipe experiments.
I hate salmon. With a passion. Chalky, dry, smelly, slimy-skinned, the worst of the worst when it comes to fish.
At least, that's what I would've said about a decade ago, when the only salmon I had tasted was over-poached at buffets or overcooked at restaurants that frankly didn't quite know what they were doing. I don't know if I was running the right circles, but it seemed de rigeur in my youth to cook salmon to a shade just past well-done. We didn't seem to exit these culinary dark ages until some time in the '90s, by which time my bias against the fish had already been firmly established.
It wasn't until I started cooking in nice restaurants (the kind that I could never afford to go to as a civilian) that I realized that it wasn't the salmon that was at fault, but rather (as usual) the cook. Properly cooked salmon is amazing. Crisp, crackly, crunchy skin that can rival the best roast chicken's; tender, moist, flavorful meat that melts across your tongue like butter. There's a reason, after all, why salmon is the most popular fresh fish in the country.
But before we even begin cooking it, let's take a quick look at what you might find at the fish counter.
There was a time not long ago when salmon was salmon. It was the pink fish that skinny people ordered at restaurants or fancy ladies in French hats would pick at on a high class buffet. These days, diners are a little more aware of what's out there, or at least that there are options when it comes to specific salmon species.
Here's a quick guide to what you might find in the market. Over the course of the next few weeks, the folks at Copper River Salmon will be sending us samples of various salmon species, so stay tuned for some more detailed updates!
- King Salmon, also know as chinook, are the largest salmon species and one of the most popular at the fish counter. In the wild they an grow to over 100 pounds and live for several years, making them prized amongst game fisherman. Large, thick filets make for relatively easy cooking, though they are not the most flavorful species. Farm-raised king salmon tend to be smaller with a bit more intramuscular fat, giving them more richness.
- Coho are far smaller than King Salmon with denser, brighter, more flavorful flesh. With relatively little intramuscular fat and a very fine texture, they're great for cured preparations such as gravlax.
- Sockeye Salmon get their name from a Halkomelem word from the indigenous people of British Columbia. Nothing to do with either socks or eyes. Known for their deep red flesh and full flavor, they are quite small, which makes them difficult to cook—thinner filets are prone to overcooking.
- Arctic Char are... not salmon. But they have a similar reddish-orange flesh colored by the carotenoid pigments they get from feasting on small shellfish. Their flavor and cooking qualities are quite similar to Sockeye Salmon, though they tend to be a little fattier.
In general, I prefer larger, fattier King Salmon for high-heat cooking methods like pan roasting. Their thicker size and higher fat content offer a little more protection from overcooking or drying out, things that salmon is prone to do in the high heat of a pan or an oven.
That said, any salmon will do as long as you are careful with how you treat it.
Bad Salmon Playbook
There's an unholy trinity of fates that can befall salmon. If you've ever cooked salmon, these are probably all too familiar a site:
The Picked Scab:
Flaky bits of salmon flesh that get stuck to the pan as it cooks. Not only does it make the finished cooked filet look like a pock-marked teenage crater-face, it also makes the pan a bitch and a half to clean when you're done. We'd rather avoid that.
Like the TMNT character of the same name, there may be something soft and tender underneath, but the dried out, stringy, crusty, downright malicious exterior is all you can pay attention to.
The Bloomin' 'Bumen
That's right. The white gunk that gets squeezed out of the layers of salmon flesh, oozy and unattractive like a popped pimple (what's up with the blemish similes today?). It's not just that it's something you don't want to eat, it's also a pretty surefire indication that the salmon you are about to put in your mouth has been overcooked beyond repair.
Luckily, the first two problems can be solved relatively easily.
A Closer Look
How many of you have been intimate with a salmon filet? Raise your hands.
I thought so. Well, it's time you made the leap. When was the last time you looked closely at the cross section of a salmon filet, I mean really closely?
Well here's what you'd see:
Starting from the top, we've got:
- Pale orange/red flesh. This is the bulk of the matter, and if you get your salmon filets skinless, then it's basically all you're left with. Depending on the species of salmon, the color can vary from a deep, dark red to a paler orangey pink. We'll talk more in a moment about salmon flesh's cooking characteristics. Right above the meat you'll find a layer of...
- Subcutaneous Fat. Depending on the species of salmon, the time of year, the availability of food, and a number of other factors, the thickness of the fat can vary, but all salmon have got it. It serves both as an energy store for the fish, and as a means of insulating its body from the large temperature changes between ocean waters and the rivers is swims to during spawning season.
- Skin. Some fish have thick, leathery skin. Salmon skin is some of the nicest around, very similar in thickness and texture to chicken skin, making it ideal for cooking.
It's these last two layers—the skin and the subcutaneous fat—that are of interest to us. We know that the role of that fat is to insulate the salmon against rapid temperature changes, so why not harness that feature in our cooking method?
Just like all meats, the texture of salmon flesh alters as a direct result of the temperature is it raised to.
- At 110°F and below your salmon flesh is essentially raw. Translucent and deep orange or red, it has the soft, fleshy texture of good sashimi.
- At 110 to 125°F your salmon is medium rare. The connective tissue between layers of flesh has begun to weaken and if you insert a cake tester or toothpick into the filet, it should slide in and out with no resistence. The meat is relatively opaque, but still juicy and moist without and chalkiness or fibrousness.
- At 125°F to 140° you are beginning to enter medium to well-done territory. Flakiness will increase, and a chalky texture will start to develop, though it won't be extreme. Albumen will start to get expelled from the between the contracting muscle fibers and will begin to coagulate in unattractive white clumps on the exterior of the salmon. In the early stages of this clumping, your salmon is still rescuable (just stop cooking it IMMEDIATELY).
- At 140°F and above, your salmon has reached its limit. From here on out, it's just going to get chalkier, dryer, and more unattractive. This is what salmon that sits in the steam table at the cafeteria looks like, and probably why you didn't like eating salmon as a kid.
So your goal is really to keep as much of the salmon below the 140°F temperature range (and preferably closer to the 125° range) as possible. To do this, make sure to always cook your salmon skin on if you're pan-roasting, even if you plan on serving it skinless*. By cooking salmon with the skin on, you can all but alleviate any sort of overcooking problems on the outer layers of flesh. The insulative subcutaneous fat acts as a heat barrier, transmitting heat to the interior flesh very, very slowly. This slow heat transfer means that skin-on salmon cooks much more evenly and gently than skinless salmon.
*Why do you want to serve your salmon skinless? is a question most often followed up by I see, and do you find pleasure anywhere in your life?
It fulfills the exact same role that a batter or breading supplies on a piece of fried chicken or a tempura shrimp—a buffer to slow down heat transfer and provide a crisp element while still keeping the flesh underneath from overcooking.
You may ask but what about the other side of the filet? Salmon only has skin on the outside, right? And right you are. We still have the problem of overcooking the skinless side of the filet. The solution? Just cook it through almost entirely with the skin-side down. Fancy pants French chefs who want to sound nerdy like to call this unilateral cooking—cooking from one side only. Personally, I cheat just a bit, flipping the salmon over for the last 15 seconds or so, just to firm up the second side.
But cooking salmon skin-on leads to a few other problems that need to be dealt with.
The Woes Of Skin-On Filets
First off, if you aren't careful, you still get the leaky albumen problem with skin-on salmon filets. Even worse is this guy:
Yep, don't tell me that hasn't happened to you before. At its worst, the skin gets solidly fused to the skillet and you end up completely separating the meat from the skin as it cooks. This in itself is not a terrible thing if you don't plan on eating the skin anyway, and indeed, if you want a skinless filet, it's the best way to do it: cook the filet skin-on, the slide a thin spatula in between the skin and the flesh to separate them.
At best, you end up with something that looks like this:
It's not the end of the world—what's left of the skin is still relatively crisp, and the flesh underneath may be perfectly cooked, but it's certainly not the kind of thing that's gonna impress the mother-in-law.
After cooking through several pounds of salmon filets on at various temperature ranges, it turns out that the key to getting your skin to stay intact is serendipitously the same method that gets you the most evenly cooked, moistest, tenderest salmon. I've broken it down into a few easy tips:
Perfect Salmon Tip 1: Preheat the Oil
Know why that salmon likes to stick to the metal pan? It's not just a matter of being, well, sticky, it's actual a chemical bond that occurs between the fish and the pan at a molecular level. This happens with all meat. With land-dwelling flesh like beef or pork, it's not quite as bit a deal. The robust flesh of land animals sticks to itself better than it sticks to a pan. The worst you'll get is a deposit of browned proteins that have been expelled from the meat as it cooks.
With tender fish, on the other hand, it's very easy for it to stick to the pan better than it sticks to itself. Rather than lifting clean, it tears. The key to preventing this is to make sure that the skin heats up as fast as possible. With a hot enough pan and enough fat in it, the skin will have heated up, causing its proteins to tighten and coagulate before it even comes into contact with the hot metal. This prevents it from forming a strong molecular bond with the metal and makes subsequent flipping easier.
Perfect Salmon Tip 2: Dryer is Better
Nothing cools down oil faster than wet stuff being added to it. Rather than working towards searing your meat, the energy from the hot oil ends up getting used to evaporate excess moisture. The dryer your meat before it goes in the pan, the better. I press my salmon filets firmly between paper towels before I transfer it to the pan skin side down.
Perfect Salmon Tip 3: Hold On Tight—She's A Fighter!
Salmon skin shrinks as it cooks due to proteins tightening and water and fat being driven off. What happens when this occurs? Like a bi-metal strip, the salmon filet will begin to curl up on itself. This curvature can cause uneven cooking—the edges of the skin in tight contact with the pan will end up overcooking and burning, while the central regions that are lifted off the pan will barely cook at all. This is not an ideal state of affairs.
To counteract this problem, I use a flexible metal fish spatula to hold the filets firmly in place as their bottom layers cook. This is of utmost importance during the first minute or two of cooking. After that, the filets shape will be set and they will continue to cook evenly.
Perfect Salmon Tip 4: Slow And Steady
In order to get perfectly crisp, rendered skin, three things need to happen simultaneously: fat needs to render out, water need to evaporate, and proteins need to set. Cook too hot and all your water will evaporate too fast. The temperature rapidly climbs, and your proteins set and start to burn before your fat has had a chance to render out properly.
You end up with salmon skin that is slightly crisp in spotty patches on the exterior layers, while still gelatinous, greasy, and fatty underneath. Preheating the pan over a relatively high heat to prevent the sticking problems explained in Tip #1, then immediately reducing the heat once the salmon is added solves this problem. You end up with shatteringly crisp, perfectly rendered, brown crunchy skin just like the best pan-seared chicken.
And here's another bird to kill with that same stone: slow and steady cooking also leads to a more evenly cooked finished result. Say goodbye to coagulated albumen!
Perfect Salmon Tip 5: Don't Flip Until It's Ready!
If there's one most important trick I've learned about pan-roasting foods in all my years cooking, it's this one: never force your food out of the pan. It'll come on its own when it's good and ready. I use a thin, flexible metal fish spatula for all of my flipping, but if I find that after some very gently prying the fish doesn't release, it means that it's not ready to come yet. Let it continue cooking and once the skin is completely rendered and crisp, it should detach itself from the pan quite easily.
Perfect Salmon Tip 6: Break Out the Thermometer
You just knew this one was coming, right? If you've been following my work at all, you'll know I'm a huge fan of the Thermapen instant-read thermometer. Get yourself one and you will never, repeat never overcook your meat again.
That is, unless you are like me and stop to take photos while the salmon is in the skillet thereby letting it come all the way up to 137°F when you were aiming for 120°F. Let me rephrase that to say, you will rarely, repeat rarely overcook your meat, and when you do, you'll know it's overcooked before it ever reaches your mouth. Better?
Perfect Salmon Tip 7: Just A Kiss on Backside
Just a repeat from what I said earlier: cook your fish almost all the way through skin-side down, as this is the side that's insulated. The reverse side needs the briefest kiss from the flame.
Follow all these tips, and you should end up with something that looks like this:
Perfectly renderd, brown, crisp, thin, salty, crackling skin with no more greasy, gelatinous fat underneath. A thin layer of ever-so-slightly flaky meat underneath that, followed by a wide expanse of tender, juicy, not-the-least-bit-chalky flesh, and a central core with a creamy, buttery texture bordering on sashimi-esque.
This is how salmon should truly taste.
It's good enough to eat on its own (or with a squeeze of lemon and a big drizzle of olive oil), but I feel like the strong flavor of salmon does very well with other bold flavors, so I went ahead and topped mine with a chunky relish made with oilves, capers, anchovies, and a few other aromatics.
It's bold enough to pair well with the salmon flesh, but soft-spoken enough to let the fish do the talkin'.
And what's that fish saying?
Get The Recipe!
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.