Why are milk lids white? Why Edinburgh supermarkets made the switch from coloured bottle caps to clear

Edinburgh residents may have noticed that their milk bottle caps have changed colour at supermarkets – but what is the reason for this switch?

Shoppers across Edinburgh have shared their confusion, after milk bottle lids changed colour overnight. It’s not just the Capital – supermarkets across the UK have made the change over the past month. Here’s why shops are now using clear or white milk lids instead of coloured bottle caps.

Why are milk lids white?

The usual coloured bottle caps have been replaced with clear or white lids – as these are easier to recycle. Red, blue and green lids are difficult to recycle back into food-grade packaging, as the plastic can cause colour contamination. However, the clear caps can easily be reused to create new milk bottles.

Before the change, the caps and bottles had to be recycled separately, but now they can be reprocessed together in a ‘closed-loop’ system. This will allow supermarkets to become less dependent on ‘virgin plastics’, which do not contain any recycled materials.

How will I tell the difference between different kinds of milk?

For years, shoppers have been able to tell if a bottle contains semi-skimmed or whole milk with a quick glance at its coloured lid. Cartons with blue tops contain whole milk, while bottles with green lids contain semi-skimmed milk. Red-topped bottles have skimmed inside, while gold lids indicate Jersey and Guernsey milk.

While supermarkets are getting rid of colour-coded lids, they will be replacing them with colourful labels, which will help shoppers quickly pick out the different types of milk.

What supermarkets are making the change?

Lidl, Aldi, Marks & Spencers, Sainsbury’s and Co-op have all committed to using clear milk lids permanently, after trialling the change last year. However, some big supermarket chains, like Tesco and Asda, are still using coloured bottle tops.

How much plastic is saved by using clear bottle caps?

Supermarket Co-op believes that the switch could remove over 150 tonnes of coloured plastic from their high-density polythene (HDPE) streams a year. A spokesperson for Aldi said that the switch will allow them to recycle around 60 tonnes of HDPE into milk bottles.