Mackerel Loaves

Saba-zushi

Preparation info

  • Difficulty

    Complex

  • Serves

    6–8

    as a main dish.

Appears in

Here seasoned rice is topped with silver-and-blue-streaked marinated mackerel to make an impressive luncheon or dinner main course. The fish must be salted or marinated overnight; instructions for both methods are included.

Though uncooked, the final dish keeps quite well for a day at room temperature. In fact, this mackerel loaf is the refined version of a very primitive method of food preservation, namely salting, and is probably the oldest known kind of sushi there is. It is particularly favored in the Kansai region (area around Kyoto, Nara and Osaka), though enjoyed throughout Japan.

Ingredients

  • 2 whole mackerel, each weighing about 1¼-1½ pounds
  • 3–4 tablespoons coarse sea salt

Marinade

  • cup rice vinegar
  • 5–6 tablespoons sugar
  • 1½–2 tablespoons usu kuchi shōyu (light soy sauce)
  • About 25–30 inches shirata konbu (pale green kelp), optional since availability is limited
  • 2 cups raw rice, cooked according to the master recipe
  • Generous ¼ cup sushi su (seasoned vinegar)
  • 8–12 sticks hajikami su-zuké (whole young ginger pickled in sweet and sour sauce)

Method

Clean, dress and fillet both mackerel (pages 28–30). Salt the 4 fillets on all sides with 3 tablespoons of salt and lay them flat in a covered glass or ceramic container for 4–5 hours in a cool but unrefrigerated spot. (Or use 4 tablespoons of salt and refrigerate the fillets overnight.) Either way, there should be a considerable amount of liquid to pour off, and the flesh should be much firmer than before. Remove the small bones down the middle of each fillet with tweezers. Carefully rinse the fillets under running cold water, then gently pat them dry.

In a small saucepan, combine the ingredients for the marinade. If you are planning on marinating the fish unrefrigerated, use 5 tablespoons sugar and 2 tablespoons light soy sauce for the marinade. (If you plan to refrigerate the marinating fish, use 6 tablespoons sugar and only tablespoons of light soy sauce.) If you have found the pale-green kelp (difficult to obtain in some areas of the United States but well worth special ordering), put it in the saucepan also and bring the mixture to a boil. Stir to make sure all the sugar has dissolved. Remove from the heat and let the kelp and marinade cool down to room temperature undisturbed. The kelp will turn a translucent golden-toned green and impart a subtle sweetness to the marinade.

Lay the mackerel fillets flat, skin side up, in a single layer if possible, in a glass or ceramic casserole or deep dish. Pour cooled marinade over the fish, cover and let them marinate for 2–3 hours at room temperature (or overnight in the refrigerator).

About 1 hour before shaping the loaves, cook the rice and season it with the sushi su. Fan the rice to cool it down as you toss gently with a wooden paddle or spoon. With damp hands, form 8 balls from the seasoned rice. Lay a damp cloth over these if you are not going to use them immediately. (The rice can be held for about 1 hour this way.)

Remove the fish fillets from their marinade and peel off the thin, transparent outer skin from each piece. Peel from the head to the tail. Arrange the fillets’ backs to each other, tails to right, heads to left, and cut them diagonally as shown. Now reverse the top and bottom pieces on the right-hand side. Not only will this make for an attractive design on the finished loaf, but it helps to even out the overall thickness of the fish fillets. Trim the right- and left-hand sides for neater loaves. (Either eat up these end pieces, or slice them very thin and toss them with thinly sliced, lightly salted, then squeezed-out cucumbers for an interesting hors d’oeuvre or side dish for another meal, which can be kept refrigerated for up to two days.)

Ideally, to shape the loaves you should have the following equipment on hand: a sudaré (slatted bamboo mat), some sarashi (white linen cloth), and four sheets of take no kawa (bark from bamboo, sold especially for wrapping such dishes as these). If not, you can still make do with a white napkin and either clear plastic wrap or aluminum foil, some stiff cardboard and rubber bands. If you do have the bamboo bark, soak 4 pieces of them in water for 15–20 minutes, remove a thin strip from each sheet to use as a tie and then pat the sheets dry with paper towels. Sarashi cloth or table napkins should be soaked in slightly acidulated water for 2–3 minutes, then wrung out very well. The sudaré mat should be dry, and so should your work surface.

Place the sudaré mat flat on your work surface and lay the damp cloth over it. Or, if you haven’t a mat, lay the cloth directly on a small cutting board. Arrange one block of mackerel (two diagonally fitted pieces), skin side down in the middle of the cloth (1). With damp hands, take two balls of rice and place one at each end (2). Push and coax the rice with your hands to cover the mackerel fillets entirely (3). Try to maintain a rectangular shape from the start. Bring the cloth and mat up over the rice to help form a straight line and sharp-edged block (4, 5). Twist the ends of the cloth gently to help shape these sides (6). Open the cloth, and if you’re using damp bamboo bark, place it over the fish and rice loaf. Now flip the loaf over and peel off the cloth (7). The bark will be on the bottom with the fish fillets on top (8). Or, use clear wrap, foil or damp linen cloths in lieu of the bamboo bark and transfer the loaf in the same manner. If you have kelp, cut it to match the length of your mackerel block and lay it across the top of the fish. Tie up the mackerel loaf snugly in bamboo bark (9) or place stiff cardboards on top and bottom of loaves wrapped in plastic wrap, foil or cloth. Secure the cardboard with rubber bands and add light pressure evenly on top—a 1-pound book or two is fine. Repeat the shaping and wrapping procedure to make 3 more loaves.

Let them set for at least 2 hours and up to 6 hours unrefrigerated. Unwrap the loaves and, with a very sharp damp knife, slice each loaf into 5–6 pieces . Avoid a sawing motion and dampen your knife after each cut. Reassemble the slices into loaves and lean 2 or 3 sticks of pickled ginger against each of them. Or, if the sticks of ginger are unavailable, garnish your platter with sliced red and pink pickled ginger.