Our household lab testers have years of experience subjecting numerous items such as prams and suitcases to unforgiving durability tests. Drawing upon the expertise of our kitchen lab experts and working in a temperature-controlled, hygienic lab environment, they deliver rigorous results that show you which plastic containers are the best.
Plastic food containers from brands like Décor and Sistema are sold in every supermarket and department store, so we scour these places to find the most common ones. We also look at popular brand names (such as Tupperware) and survey manufacturers about availability. We then buy the plastic containers just as a consumer would, to ensure we're getting a product that everyone else is, that hasn't been "tweaked" in any way. As there are so many plastic containers on the market, we concentrate on popular 1L varieties.
Plastic containers need to be as air-tight and leakproof as possible. Ideally, they won't smell or stain after cleaning, and be durable enough to last many dishwasher cycles. They must also be easy to use.
These moisture absorbent beads change colour when they are wet.
Our plastic containers are subjected to a range of tests.
To see if air gets into the plastic container, we place moisture-absorbent silica beads that change colour when wet into the containers, and plunge it into a large bucket of water for two minutes. We then observe if any moisture has entered through the lid. If water can get into the container, it's likely air will, too. The more water in the container, the lower the score.
Some plastic containers stain more easily than others, as our tests reveal.
You don't want soups or juices to leak out of your container while travelling. We place 500mL of water into the container, along with some food dye. We then shake and tip it over absorbent paper for 30 seconds to see if any droplets appear. The more it drips, the lower the score.
Odour and stain test
Some foods can leave orange stains on plastic containers, and the smell can linger even after multiple washes.
We put spaghetti bolognese into the plastic containers, leave them in the fridge overnight and reheat them in a microwave for several minutes.
We then remove the sauce, and put the container in the dishwasher. After washing we score the containers for any staining, and comment on whether there are any strong odours.
This test is to see how strong the plastic containers are. We freeze 500mL of water in the containers, and drop them onto a hard surface from a height of 900mm. We note any cracks or damage. We don't score this but we comment on any damage.
Frozen plastic containers are more brittle. Our durability test separates the strong from the weak.
Lid strength test
We remove and replace the lid 100 times and see if it's still airtight and leakproof.
We heat and reheat 500mL of water in the plastic containers multiple times and observe any damage.
Ease of use
We rate ease of storage, removing and replacing the lid, and ease of cleaning (the fewer pieces, the better; models with removable gaskets which could trap mould or become lost score lower).
Performance makes up 70% of the CHOICE Expert Rating, and ease of use 30%. We recommend products with a CHOICE Expert Rating of 80% or more.
Stock images: Getty, unless otherwise stated.