No use crying over spilled milk?

13th Feb 19 by Christina O'Sullivan

Are we wasting far too much milk because supermarket 'Use By' dates are too conservative?

Last year when the ‘Beast from the East’ was covering us with in an icy blanket of snow, I got a message from a friend explaining that she couldn’t get out to the shop but the milk in her fridge was past its ‘Use By’ date – what to do? I swiftly responded telling her to sniff it and that if it smelled ok it would be fine. Through life experience and common sense, we know that milk is often safe to drink past the ‘Use By’ date, unlike Cinderella’s pumpkin milk does not transform at the stroke of midnight.

At Feedback, wanted to test this theory – specifically with food science. We commissioned the University of Chester’s NoWFOOD Centre to test milk from four supermarkets (Tesco, Sainsbury’s, Morrisons and Asda). The results suggest that milk, when stored at optimum conditions (which meant that the milk was unopened until it was tested, and stored at the recommended fridge temperature of below 5 degrees Celsius) was safe to drink seven days after the supposed ‘Use By’ date.

It’s understandable that supermarkets want a buffer period for food safety, but that period must be reasonable, particularly when you considering the environmental impact of pouring milk down the drain. Globally, the meat and dairy industries exact a huge toll on our global environment and are major drivers of climate change, estimated to account for 15% of total global emissions – more than the entire global transport sector. At an individual level, although milk is not the most wasted food, milk waste represents the highest contribution to greenhouse Gas Emissions compared to other food as it is so widely consumed and resource-intensive to produce. Milk waste also represents a waste of water; research by the UK Institution of Mechanical Engineers shows that on average it takes 1000 litres of water to produce just one litre of milk. The water used to produce milk that is ultimately thrown away as a result of date labels is enough to fill 20,000 Olympic swimming pools.

Supermarkets argue that date labels need to take account of variables such as milk spending a lot of time out of a fridge, or fridge temperatures being set too high. However, with the buffer for milk stored in optimum conditions as high as seven days and considering that in other countries including Norway and Denmark they trust citizens enough to use a ‘Best Before’ date and encourage them to use their senses, there is an opportunity to adopt a more realistic approach to reduce waste. Research by WRAP suggests that extending milk ‘Use By’ dates by just one day could save around 30 million pints of milk a year.

Instead of crying over spilled milk we should be calling on supermarkets to act to stop millions of pints of milk going to waste. They hold the power in our food system so they must be held to account. Here’s three things you can do today:

  • Only buy the milk you need and store it at the correct temperature (below 5 degrees – for more information see the WRAP ‘Chill the Fridge Out’ campaign) to avoid waste.
  • Where you feel confident to do so, use your senses, including the ‘sniff test’ and checking the texture of milk, to determine whether milk is still good to drink.
  • Tell your supermarket you want change – write to them now

Here are details of the milk testing carried out:

Food safety testing was conducted at the NoWFOOD centre at the University of Chester. They used the AOAC 3M petrifilm accredited method for Aerobic Colony Count. The dilution factors were chosen to cover the range of expected growth. Samples were sequentially diluted in a Peptone solution. Each dilution was a factor of 100. Three samples of milk were tested every day (totalling eight days) from each supermarket, totalling twenty-four samples for each supermarket. Milk was stored in the fridge unopened until it was tested. The results showed that each sample was safe to consume. The milk was stored at between 4-6 degrees Celsius and at least one of the milk bottles spent 2 hours in the car on route between the supermarket and the lab, simulating the journey of milk to a household fridge.

What can you do next?
How long does it take: 2 minutes

Challenge supermarkets to reduce milk waste

Write to your supermarket