Chinese Rice Boxes.

Condensation, and it is a packaging problem rather than a cooking one.

Freshly steamed rice sits at around 90°C and keeps giving off water vapour long after it is boxed. Inside a closed container that vapour has nowhere to go, so it condenses on the lid and walls and runs back down into the rice. Fifteen minutes is enough to leave the top layer wet and the edge grains gluey.

The fix is venting — but it comes with a genuine cost, and it is worth deciding deliberately:

• More venting protects the texture and loses heat faster.
• Less venting keeps the rice hot and lets it degrade.

We size perforation against your actual delivery times. A kitchen doing ten-minute local hops can afford much more venting than one doing thirty-minute routes across a city.

Two other things help: do not overfill to the rim, and do not box rice straight from the steamer if you can rest it for a minute first.

Give us the cooked weight of your portion, not the dry weight — this is where most sizing errors come from.

Rice roughly triples in weight when cooked. A portion measured as 100 g dry arrives in the box at around 300 g, which is a very different container.

A typical single serve lands around 250–350 g cooked, with sharing portions above that. In oyster pail terms that is usually the 16 oz pint size for a single and 26 oz upward for sharing.

Leave headroom deliberately. Rice filled flush to the rim gets compressed by the lid, which makes the steam problem worse and looks worse when the customer opens it.