Hi, and welcome. A rice ball looks like the simplest thing in the world, just rice pressed into a triangle with something hidden inside.

But plenty of first attempts fall apart the moment you pick them up, or turn gummy because the rice was packed while it was still steaming hot. Get three small details right, warm rice, salted hands, and a firm but gentle press, and you'll have onigiri that hold their shape all the way to lunch.

Start with the right rice

Short grain Japanese rice is what you want here, the kind sold as sushi rice or koshihikari. Long grain rice won't clump the same way and your triangles will crumble. Rinse 2 cups of rice under cold water until the water runs mostly clear, then cook it however you normally do, rice cooker or saucepan. While it cooks, mix 1 teaspoon of salt into 2 cups of water in a small bowl for wetting your hands later. You'll also want a sheet or two of nori cut into strips, and a small bowl of fillings ready before the rice is done.

Shape while it's still warm

Timing matters more than technique. Rice is sticky when warm and loses that grip as it cools, so shape the balls within about ten minutes of the rice finishing. Let it steam off for five minutes first, then spread it into a wide bowl so it cools evenly. Dip your hands in the salted water, shake off the excess, and take a handful of rice, roughly 90 to 100 grams, into one palm. Press a small hollow in the center with your thumb, drop in about a teaspoon of filling, then close the rice around it.

Fillings that behave

Wet, loose fillings leak and ruin the shape, so pick things that stay put. A piece of grilled salmon flaked with a fork, a spoon of umeboshi, or a small chunk of teriyaki chicken all work. Tuna mixed with a little mayonnaise is popular and holds together well. Keep the amount small, about a teaspoon, or the rice won't seal over it. If you're making several, set up a small tray and shape them one by one rather than assembling everything at once.

The press that holds it

Cup the rice in one hand and use the other to form a triangle, turning it a quarter turn between presses. Three or four firm squeezes is enough. Press too hard and the rice turns dense and chewy. Too soft and it falls apart. Wrap each ball in a piece of nori right after shaping, or set it in a small paper cup if you're packing a bento, which keeps the shape and stops the rice from sticking to the box.

Packing it for later

Onigiri are best eaten the same day. If you're making them in the morning, let them cool completely before closing the bento lid, or condensation will make the nori soggy. Wrap each one individually in plastic wrap if you're carrying it loose in a bag. They'll keep at room temperature for a few hours, which is why they show up in so many packed lunches. Add a few cherry tomatoes and some pickled vegetables to the box to round it out.

Once you've made a batch, the whole thing takes about 40 minutes start to finish, with 20 of that hands off while the rice cooks. The trick is really just the warm rice and the salted hands, everything else is flexible. Try it once with a simple salmon filling, then start swapping in whatever you've got in the fridge. You'll get a feel for the press after two or three, and after that it's one of those things you can make without thinking.