Is there any animal that we eat that's more mystifying than the octopus? An octopus can camouflage itself and shape-shift in ways that sci-fi nerds only dream of. They have a complex and decentralized nervous system that allows each individual limb to register senses and make decisions independently. Plus, octopuses have repeatedly demonstrated escape-artist abilities; one even broke out of its enclosure and retreated through a drain pipe to the ocean.* And what about that plural—is it "octopuses" or "octopi"? (At Serious Eats, we use "octopuses.")
But perhaps the realm where the octopus really vexes is in the kitchen. Just look at the crazy things people have done in pursuit of tender tentacles: beating the poor beasts against rocks, tossing wine corks in the pot with the hope they'll work some dark magic, even dropping the cephalopods in washing machines and running the spin cycle. When someone says they prefer Tide for laundry, this isn't what they meant.
Cook enough octopus, though, and all of this becomes obviously silly. There's nothing hard or mysterious about it, you just need enough heat in combination with enough time to make an octopus tender. How you determine those two variables depends on the cooking method.
To explore this further, I tested octopus cooking methods to find the best ones (well, most of them; I didn't test roasting it, though that, too, can work). I tried out superstitious old techniques like the wine cork, as well as newer ones like sous vide. Below are the keys to success.
*While an animal’s intelligence shouldn’t be the only reason we try to protect them, it’s hard not to feel some likeness with such a clever creature. We can all do our part by keeping an eye on Seafood Watch’s recommendations and avoid any sources of octopus that are unsustainable.
What You Need to Know Before You Cook Octopus
An octopus is a mollusk, more specifically a cephalopod along with squid and cuttlefish. Just like squid and cuttlefish, an octopus's flesh is packed with muscle fibers and collagen, the tough connective tissue that also strengthens a mammal's ligaments and tendons. This collagen makes octopus flesh rubbery, at least initially. With enough heat and time that collagen breaks down into silky and tender gelatin, and the octopus grows tender with it. It's really no different than stewing gristly chunks of beef in a stew; eventually they become soft and tender.
If you're wondering whether I'm implying that octopus should only be prepared using a lengthy cooking method, I mostly am, though there are exceptions. Octopus can be eaten raw (alive, even, assuming you don't find that inherently cruel), and it can also be prepared using quick-cooking methods like sautéing, though it's riskier to do that than with, say, squid, a related animal that starts out much more tender.
Anatomically, an octopus is intimidating. There are those eight tentacles covered in suckers, radiating out from the floppy head; two small eyes; and a beak. A beak? Yeah, a beak. It's right where the eight legs converge. A person couldn't be faulted for feeling a little lost about what to do with this particular physical form. It's simple though: Do very little before cooking the octopus. Some sources suggest cutting out the beak and eyes beforehand, but I find it much easier to remove those parts when the flesh isn't as slippery as it is when raw.
In almost all cases, the head itself will already be cleaned when you buy an octopus. You'll be able to tell because there will be a large slit allowing you to stick your hand inside, like a puppet. Do it, jam your hand up there, even flip it inside out, but, you know, have some respect—save the impromptu puppet shows for your socks. Dig around to make sure nothing major was left behind. What's major? Ink sacs, slimy blobs, unidentifiable stuff that you can pull out. You don't have to scrape it clean, but you also don't want to leave globs of innards behind. Also give it a good rinse, since there's sometimes sand hiding there.
You can cut up an octopus before cooking it, though in most cases cooking it whole and cutting it after is easier (sous vide is one exception to this). If you need to, use a sharp knife and steady hand, because I promise you, the raw octopus won't be steady for you. Even easier, grab a good pair of kitchen shears. If you do end up butchering the octopus while raw, you might as well locate the hard beak and remove it along with the eyes.
Most octopus you buy from a fish counter will have previously been frozen, or still is. There's nothing wrong with this. It might even help: The ice crystals that form in the flesh can create micro-lacerations that help tenderize it.
Tenderizing Octopus Before Cooking
Aside from freezing, there are some other methods that people claim can help tenderize the meat before cooking. I didn't try all of them—massaging the tentacles with salt for 20 minutes, which is what sushi chefs do, is needlessly laborious unless you're a sushi chef. But I did try beating an octopus with the flat side of a meat tenderizer for about a minute to see what effect it had.
The answer: nothing, at least nothing that I noticed. Compared to an un-beaten tentacle from the same octopus cooked for the same amount of time in the same pot of water, I was unable to detect any difference in texture, tenderness, or cooking time. It might work if you whale at it hard and long enough, but you'll likely sooner damage your countertop or get a call from your neighbors asking you to please stop being such an a-hole.
Phase One: Cooking Octopus Until Tender
In most cases, octopus needs to be cooked until tender no matter what the final cooking method will be. Even if you ultimately plan to sear or grill the octopus, you first need to cook it to tenderize it sufficiently. There are several ways to to do this, some faster and some slower. They'll all get you there in the end.
Blanching: Do You Need to Do It?
I once worked on a farm in Galicia, Spain, which should immediately signal to octopus cognoscenti that I was in serious octopus country. There, the farmer Vicente taught me to make one of the region's iconic dishes, pulpo gallego. He showed me how to dip the octopus three times in the simmering water before lowering it in for the duration of cooking. He claimed this helped set the fragile purple skin to prevent it from falling off later.
I've never had a reason not to follow his instructions, but for this article I tested it. I found that blanched skin tore just as easily as non-blanched skin. If you want to keep the skin intact, you're better off chilling the octopus after cooking it, which really does make it more resilient.
While blanching doesn't help with the skin, it acts like a curling iron for octopus, setting the limp tangle of tentacles into graceful twirls. That's not a necessary step if you're just going to boil the octopus in the pot (it'll curl up all the same there, with or without the dipping sequence), but it's not a bad idea for sous vide, since the pressure in a vacuum bag can hold the raw tentacles in positions that come out looking like some kind of undersea contortionist act.
What About the Skin?
Some recipes say to remove the purple skin after cooking. That's nuts. The skin and the gelatinous, almost fatty layer under it are some of the best parts of the octopus. The kind of people who remove that are the same ones who pull the paper-thin brown and crisp skin off roast chicken and push it to the side of their plate. Please, I beg you, don't be one of those people.
Medium Speed: How to Cook Octopus in a Pot on the Stovetop
Humans have been boiling octopus for about as long as we've been eating it. It works. But there are still some ideas out there about how to make it work better. I experimented with a couple approaches: with and without a cork in the pot, and using a cold versus hot start. All my octopus samples reached tenderness in the same amount of time—about one hour—and I couldn't spot a lick of difference among them.
The cork trick is an old folk method that some chefs swear by. In all my years cooking octopus in restaurants I'd never noticed a difference, but I still needed to test it more methodically. The results bolstered my suspicion that a cork is little more than a psychological crutch to give nervous cooks a boost in confidence. Perhaps there's a particular kind of cork that does something helpful to speed things up, or perhaps I needed to add more than one cork to my pot. But in any case, I don't really see the point. Even if there is some effect I managed not to detect, an octopus will still become tender with or without a cork. How long that takes depends on the octopus itself; different varieties and different individuals will be different sizes and have varying collagen levels, all of which will change exactly how long it takes. You'll know the octopus is tender when you can slide a paring knife into its flesh with little resistance.
The starting temperature of the water didn't have any effect either, with the octopus coming out the same no matter whether it was in the pot as the water heated up or went in after the water was simmering. I suppose there's some infinitesimally small benefit to starting in cold water simply because it's marginally easier to put everything in the pot and let it go rather than waiting around for the water to boil.
High Speed: How to Cook Octopus in a Pressure Cooker
As I've written before, a pressure cooker is an excellent way to speed up the cooking time of octopus. By trapping steam and raising the pressure inside the cooker, and therefore raising the boiling point of the water as well, you can cook octopus much more quickly than at a standard sea-level boil of 212°F (100°C).
In my experience using two different pressure cookers (a stovetop model and an electric multi-cooker), I've been able to tenderize a two- to three-pound octopus after just 15 minutes at high pressure (12- 15psi), not including the time it took for the cookers to come up to pressure. Keep in mind, though, that a pressure cooker is a black box: Once it's sealed and at pressure, there's no way to check the status of what's inside until you depressurize and open it. This does introduce a small amount of risk. You could possibly undercook the octopus, in which case you'd have to simmer it longer or return the cooker to pressure for another few minutes; or, worse, you could overcook your octopus. If you're new to using a pressure cooker for octopus, you may want to err on the shorter side of cooking times until you dial in on the number of minutes that work using your device.
Slow Speed: How to Cook Octopus Sous Vide
If the pressure cooker is the fast lane of octopus cookery and a pot on the stovetop is the cruising lane, using a sous vide setup with an immersion circulator is a leisurely country drive. What it offers are reliably consistent, set-it-and-forget-it results that rival all the other methods in terms of quality. What it requires of you is enough time and advance planning to do it, which I found to be about five hours.
I ran tests at 140, 160, 175, 180, and 185°F (60, 71, 79, 82, and 85°C), testing the samples at five hours, eight hours, and 24 hours. The octopus cooked at 140 and 160°F were still chewy even after 8 hours; by 24 hours, the 140°F sample was good while the 160°F sample had turned to an unpleasant mush. I could have sought out the ideal cooking time for the 160°F sample (somewhere around 10 to 12 hours, probably), but I didn't see the point since I'd already zeroed in on a much better combination of temperature and time: 175°F for five hours. Why cook at 160°F for 12 hours when 175°F gets you great results in less than half the time?
For those curious, the samples cooked at 180°F and above were overcooked and inedible even at the five-hour mark. While a shorter cooking time undoubtedly would work at each of those temperatures, at that point you might as well just simmer them on the stovetop since the cooking times and results will be similar and the setup is easier.
In addition to temps and times, I also experimented with adding salt and olive oil to the bags. Be careful with salt as it can quickly become aggressive on seafood that already has a natural salinity; you can add a tiny pinch, but be very sparing. Or, just season after. The olive oil seemed unnecessary as well; it added a pleasant flavor, but one that you can just as easily add later with fresh olive oil after the octopus has come out of the bag.
As mentioned above, it can help to set a more presentation-worthy shape if you dip the tentacles in simmering water first before vacuum-bagging them. It's also easier to cut the octopus up into parts (individual or groupings of tentacles, plus the head) before bagging, otherwise the sprawling shape of the octopus can make it difficult to get all the air out of the bag.
When it's done, you can chill the octopus in the bags, opening them once you're ready to proceed.
Phase Two (Optional): Sear or Grill
Once your octopus is cooked to the point of being tender, you can serve it right away while still hot; chill it and then use it like that in cold preparations (I like it in seafood salads); or sear or grill the octopus to brown and crisp the exterior.
When searing and grilling, it's a good idea to chill the cooked octopus first, a step that sets the skin and keeps it from sloughing off during the secondary cooking.
In both cases you want to work over high heat, with the oil in your skillet nearly smoking, or directly over the hot coals on a grill. Since you've already cooked your octopus to the point of ideal tenderness, you only need to cook each side long enough to reach your desired level of browning, and to warm the octopus through. As soon as that's done, it's ready to be served.