Which? research has revealed that Ocado delivers the freshest food and drink out of the UK’s six biggest online supermarkets.
We used mystery shoppers to place online orders for 25 items each from Asda, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose, totalling more than 1,700 groceries, to test how fresh their perishable goods really are.
Here, we explain our findings, including the supermarket that delivered sausages a stomach-churning 11 days past their use-by date.
Supermarkets rated for freshness
Online-only Ocado (Ocado.com) was the freshest supermarket, with perishable items lasting an average of just over 11 days until midnight on their use-by date. At the other end was Sainsbury’s, where perishable groceries lasted an average of just over nine days. Here’s how all the supermarkets compared:
Two supermarkets delivered potentially dangerous food
But these averages mask some appalling results, including three items that had already gone past their use-by dates when they were delivered.
Sainsbury’s was the worst culprit, supplying ‘fresh’ frankfurters that were a revolting 11 days out of date, and a block of stilton with a use-by date of the previous day.
Asda delivered stilton that was three days out of date.
All of these items could have been dangerous to eat.
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The groceries that had just a few hours remaining
Our shoppers also took delivery of five products where the use-by date was the same day.
Pity the shopper who received a quiche from Sainsbury’s at 6pm on its use-by date – leaving just six hours to eat it safely. Or the customer who received eight pork sausages from Morrisons with just eight hours left on the clock.
Our shoppers also filed numerous reports of food that was damaged or looked past its best, despite being within its official use-by date.
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Which groceries have the best shelf life?
When we surveyed 2,000 online supermarket shoppers, a massive 72% said the shelf life of groceries was an important factor in getting the best value for money. That’s understandable given prices at the moment: wasting food is now hitting people’s wallets, as well as their environmental consciences, harder than ever.
We only ordered products with use-by dates (as opposed to best before, or no dates), as this is the most crucial measure of food freshness – and we found significant differences between products.
The individual item with the longest life – a piece of stilton from Sainsbury’s – had 37 days until its use-by date. Stilton in general also had the longest average life of all the groceries in our investigation, at 26 days. Others with a longer-than-expected average life included chilled frankfurters, yoghurts and bacon.
Here are the groceries with some of the biggest differences in shelf life in our mystery shop – both for better and worse – compared to what shoppers in our survey expected:
Overall, the dairy items in our investigation had the longest life of all the different types of groceries we ordered, at nearly 19 days. So it’s generally a safe bet to order cheese, yogurt or cream online if you’re after products that don’t need to be consumed imminently.
At the other end of the scale, pre-cut melon had the shortest life, at three days on average, closely followed by pineapple chunks and carrot batons. Pre-cut fresh fruit and veg generally doesn’t have a long life, so it’s best to plan to eat meals involving those types of products as soon as possible after your delivery.
Is it better to shop in-store?
If buying food with a decent shelf life is a priority, it’s worth knowing that people who shop in-store are more satisfied with the freshness of their groceries (73%) than those who have online deliveries (65%).
That’s probably because when you’re in the supermarket you’re able to pick the items with the longest shelf lives, something half of those who shop in-store told us they always do.
Several shoppers told us they avoid ordering foods that tend to go off quickly when shopping online. Many also spoke of a distrust that supermarket pickers would choose the same items they would select if they were shopping for themselves.
One shopper said: ‘I find the pick and packers don’t always look at the use-by dates. They just see the product listed and throw it in the container. When shopping in-store I always go for the furthest away dates. It helps with budgeting.’
Another added: ‘I find produce is generally shorter dated when shopping online. In-store, I can choose products more freely and go for the longest date. [That’s why] I prefer to shop for certain products in-store.’
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Supermarket staff speak out
We’ve heard from supermarket staff working behind the scenes.
One Asda worker told us: ‘You’re told to pick the freshest. “Would you buy it yourself?” is what my old manager used to say. However, from a driver point of view, that’s not always the case. I’ve had mouldy, squishy produce in some of the containers the customer has handed back for obvious reasons.
‘The pickers are monitored using a pick speed per hour. But I have heard management having words with pickers about their pick speed and saying it needs to improve. They are more concerned with speed as opposed to quality. I think a lot of the problems come down to poor staffing levels and inadequate training.
‘I’ve known pickers to go out with another colleague [to be trained] for an hour then told to go on their own – me included. I was helped for all of 20 or 30 mins then I was on my own. When I came across a problem I had to wander around the shop, looking for another picker for advice.’
Should you complain?
Most supermarkets have policies guaranteeing the minimum life of perishable groceries in online deliveries. But as our investigation has shown, this sometimes fails.
Of the shoppers we surveyed who were dissatisfied with the freshness of their online groceries, only 24% complained to the supermarket – but you should always do so as you’ll probably be offered a refund.
Of those who were dissatisfied with the shelf life of their groceries, the most common response was to change meal plans (30%).
But worryingly, 23% ate products after their use-by dates – something which could put your health at risk. And sadly, 18% threw the food away.
What’s the difference between use-by and best-before dates?
Use-by dates and best-before dates are often mixed up – but the difference between them is critical.
Use-by dates are about safety: you should never eat food past midnight on its use-by date, even if it looks and smells fine. But you can freeze food up until its use-by date if you think you won’t use it in time.
On the other hand, best-before dates are less important and are all about quality rather than safety. Food may not be at its best past the date, but it’s unlikely to do you serious harm.
You can sniff or touch food past its best-before date to see if it seems OK to consume. But you should never do this for groceries past their use-by date.
Manufacturers are responsible for deciding whether or not to put a use-by or best-before date on their products. They do this according to the type of food and how it is made. This must be based on robust evidence, which is often microbiological risk assessments or shelf-life studies that help prove the length of time a product will stay safe.
There have recently been big shifts away from use-by dates for some products. Some milk has moved from use-by to best-before dates. The same applies to yoghurts, many types of hard cheese and pasteurised fruit juice.
How do supermarkets’ policies vary?
When we put our findings to the supermarkets in our study. They all told us staff are trained to pick the freshest items and that customers could return anything they weren’t happy with.
Ocado lists items in use-by date order on email receipts. Morrisons does this for those whose shopping comes from a fulfilment centre, but not for shoppers receiving their order from a store, so it depends where you live.
Some supermarkets, such as Ocado and Tesco (and sometimes Morrisons, as above), display minimum life guarantees on their webpages. Asda and Sainsbury’s list a ‘typical life’ on some products, but this isn’t a guarantee. Waitrose doesn’t do either but says its staff are trained to pick the freshest produce.
At supermarkets such as Sainsbury’s and Tesco, staff can mark items as having a short life and this appears on the customer’s delivery note.
But shockingly, we found none of the items delivered on their use-by date were flagged by the driver to our mystery shoppers on the doorstep. We think this is something that supermarkets should do wherever possible.
Sainsbury’s said: ‘We deliver more than 85,000 orders a day on average and are sorry that this tiny number of examples has not lived up to our usual high service.’
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About our research
Opinium surveyed 2,000 UK adults about their grocery shopping habits on behalf of Which? between March 31 and April 4 2023. Data was weighted to be nationally representative.
For the mystery shop, we used 12 people across the UK to order the same types of 25 perishable items from Asda, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose between 27 March and 6 April 2023. We added up the number of full hours remaining from the time of delivery to midnight on the use-by date for each item to calculate averages per supermarket and per item.