Soft Shell Crab and the Spider Roll

The legs sticking out of both ends of a spider roll put a lot of people off, and the explanation for them is more interesting than the roll’s name suggests.

A crab that has just outgrown itself

The first thing to clear up: there is no such animal as a soft shell crab. It is an ordinary hard-shelled crab, caught at one particular moment in its life.

A crab’s shell is an external skeleton and it does not grow. So to get bigger, the crab has to abandon it. It grows a new, soft shell underneath the old one, splits the old one open at the back, and backs out — legs, claws and all — leaving behind a complete empty crab-shaped husk.

For a few hours after that, the new shell is pliable. Then it takes up water, hardens, and the animal is armoured again. Catch it inside that window and every part of it is edible.

Why that makes it expensive to produce

The window is the problem. Crabs do not moult on a schedule anyone controls, and a soft crab that hardens is just a crab again.

The traditional approach is to hold crabs that are showing signs of an imminent moult and watch them closely, then remove each one as soon as it has shed. Miss it by a few hours and the batch is worth a fraction of what it was. That is labour and attention rather than raw ingredient cost, and it is why soft shell crab is a treated as a specialty item rather than a staple.

It is also why it is almost always sold frozen. Freezing at the soft stage is how the window gets extended from hours to months, and a properly frozen soft shell crab is a perfectly good one.

Yes, all of it

This is the part that stops people, and the answer really is that simple: you eat the shell, the legs, the claws and the body together, in one piece.

What you get is a texture no hard-shell crab can give you. The exterior is thin and crisp after frying, and the inside is soft crab meat, and the two arrive in the same bite instead of requiring you to extract one from the other. Nobody is picking at anything with a small fork.

The flavour is milder and sweeter than people expect — closer to the crab in a California roll than to anything strongly marine. It is the texture that makes it, not the intensity.

If you have avoided it because you assumed it would be crunchy in an unpleasant way, that is the wrong picture. A soft shell crab is crisp on the outside because it was fried, not because there is anything hard in it.

Why it is called a spider roll

Straightforward, and slightly unfortunate for the dish’s popularity.

A whole fried crab is wider than a roll, so when it goes inside, the legs and claws have nowhere to go but out of the ends. The finished roll has spindly fried limbs protruding from both sides. Somebody looked at that and said spider, and the name stuck across the entire American sushi menu.

It is a rare case of a specialty roll name that describes the food rather than selling it. Most roll names are marketing — there is a whole taxonomy of that in specialty roll names, decoded — but Spider is just an accurate description of what turns up on the plate.

Our Spider is listed as deep fried soft shell crab with crab, in five pieces. The Jumbo Spider is listed as a lightly fried spider roll, which means the assembled roll goes through the fryer as well as the crab inside it.

The appetiser or the roll

Both are on the menu and they suit different appetites.

The appetiser is the honest version. The crab arrives whole with nothing competing, so you actually taste it, and the crispness is at its peak because nothing damp is touching it. If you have never had soft shell crab, order it this way once before you meet it inside a roll.

The Spider roll is the more familiar format and the easier sell. The crab is buffered by rice and sauce, which makes it approachable but also means the crab is one voice among several. The legs still stick out, which some people enjoy and some find alarming.

The Jumbo Spider takes it further again by frying the whole roll. That is a rich order — fried crab inside a fried roll — and it belongs with the rest of the fried roll section rather than with the delicate end of the menu.

Timing matters more than usual

Everything about this dish is a race against moisture.

A whole fried crab has a large surface area and a thin coating, which is exactly the combination that goes soft quickest. Inside a roll it is worse, because it is pressed against damp rice on every side. The difference between a spider roll eaten immediately and one eaten twenty minutes later is not subtle.

So: order it, and eat it when it lands. Do not order it as part of a large table order that will arrive in stages, and do not order it for delivery — it is on the short list of things that genuinely do not survive the trip. More in Japanese takeout that actually travels.

Where it sits among the other shellfish

The appetiser list has several shellfish options and they are doing quite different things.

• Soft shell crab. Whole and fried. Texture is the point.
• Garlic Shrimp. Cooked in a sauce rather than fried, so it is the one that is not racing the clock.
• Mixed Tempura. Listed as tempura fried shrimp and veggies, cooked with panko.
• Baked Green Mussel. Warm and sauced — see the baked section.
• Calamari Tempura. Squid, and a completely different animal — more in squid and octopus.

If you are ordering two appetisers, take one from the fried group and one from outside it. Two fried starters is a heavy opening, and only one of them can be eaten first.

Frequently asked questions

Do you eat the whole soft shell crab?

Yes — shell, legs, claws and body together. During the moult the new shell is soft enough to eat, which is the entire point of the dish.

Is soft shell crab a different kind of crab?

No. It is an ordinary crab caught in the few hours after it has shed its old shell and before the new one hardens.

Why is it called a spider roll?

Because the crab is wider than the roll, so the fried legs stick out of both ends.

Does soft shell crab taste fishy?

Not particularly. It is mild and slightly sweet, and the fried coating is a large part of the flavour.

Is a spider roll cooked?

Our Spider is listed as deep fried soft shell crab with crab, so the filling is cooked. Check any roll individually rather than assuming — see sushi without raw fish.

The short version

A soft shell crab is a regular crab caught in the few hours after it sheds its shell, which is why the whole animal is edible and why it is a specialty rather than a staple. Fried whole, it gives you crisp and soft in the same bite.

Try the appetiser before the roll, eat it the moment it arrives, and do not let the legs put you off.