Containers decide whether leftovers get eaten

This is written to be used rather than admired. Each section below is a decision about food containers, and each one has a default.

Depth changes safety and quality

A deep container of hot food cools slowly at the centre, which matters both for texture and for the guidance on cooling cooked food. Shallow containers present more surface and bring the temperature down considerably faster.

They also reheat more evenly, since the heat has a shorter distance to travel to the middle. A tall tub of stew reheated in a microwave is boiling at the edges while still cold in the centre. Local food safety guidance covers how quickly cooked food should be cooled, and shallow storage is what makes that achievable.

Visibility is a behavioural issue

Food in an opaque container is out of sight and reliably forgotten, which is how most leftovers are wasted. A transparent container makes the contents obvious every time the fridge is opened. Where containers are opaque, labelling becomes essential rather than optional.

Keeping leftovers on a designated shelf rather than distributed through the fridge has the same effect. These sound like trivial points and they account for a large proportion of household food waste.

Seals, stacking and the lid problem

A lid that does not seal properly lets food dry out and lets smells transfer between items. Containers that stack save space and, more importantly, keep the contents visible rather than letting them be buried behind something taller. A collection of mismatched containers with lids that fit some and not others is the usual state of a kitchen drawer.

The part that matters: one set of matching containers in two or three sizes is a genuine upgrade over a large mixed collection. Lids stored with the containers rather than in a separate heap is the difference between a working system and a two-minute search every evening.

Materials and their trade-offs

Glass does not stain or hold smells, tolerates the oven in many cases and is heavier and breakable. Plastic is light and cheap, and it stains, warps over time and retains odours from strongly flavoured food. Metal containers are durable and stack well, though they are opaque and most of them cannot be used in a microwave at all.

If you are short of time, whichever material, the manufacturer instructions on heat and dishwasher tolerance are worth reading once rather than guessing.

A mixture is reasonable, with glass for anything that will be reheated and plastic for cold storage and transport.

Sizing to portions

Containers sized to a single portion mean you take out exactly what you will eat and leave the rest sealed. A large container opened repeatedly exposes the whole quantity to air each time, which shortens its life. For freezing, portion sizing also removes the problem of thawing more than you need.

Nine times out of ten, very small containers are useful for exactly the things most often wasted, such as leftover sauce, half an onion or a spoonful of paste. Matching the container to the portion rather than to the batch is what converts a batch into several meals.

Keeping the collection under control

Containers accumulate steadily over years, and a drawer that will no longer close is a drawer in which nothing can actually be found. Discarding anything without a matching lid, and anything warped or heavily stained, usually halves the collection. Reused packaging works perfectly well for short cold storage, though it usually seals poorly, stacks badly and warps in a dishwasher.

A small number of good containers in constant rotation is worth considerably more than a large number of mismatched ones in a heap. The test is simple: if it does not get used in a month, it is taking space from something that would.

The takeaway

Shallow, transparent, stackable and sized to a portion, with the lids kept in the same place as the boxes.

The good version is the one you can make on a Wednesday.