/ Food & Drink, Shopping

Some packs of salmon are punching below their weight

Smoked salmon in kitchen scales

I’m not in the habit of weighing my shopping after I buy it, and I’m sure that’s the case for most people. But maybe I should start – if our snapshot sample of supermarket smoked salmon is anything to go by…

Getting 10% off my shopping would normally be something I’d welcome. But I got a reduction of a less desirable kind when I bought a pack of smoked salmon from Tesco that weighed almost 10% less than it said on the pack.

This pack was one of 32 we bought and weighed from Asda, Morrisons, Sainsbury’s and Tesco when researching the weight of smoked salmon. The majority of packs bought from each supermarket were underweight, with the Tesco pack being the most extreme example.

Almost 80% packs were underweight

I was prompted to go trawling through supermarkets for salmon after a tip-off from Which? member Loz Farmer. He told us that during the past two years he’d bought four packs of Sainsbury’s smoked salmon and found them to be around 10% short when he’d weighed them.

When we bought our own samples, 25 of the 32 – nearly four out of five – weighed less than the amount stated on the packs. The other seven packs weighed more.

The ‘200g’ pack of Tesco Everyday Value Smoked Salmon actually contained 181.5g when we weighed it, meaning it was underweight by just over 9%. We believe this breaks Trading Standards rules.

Where do you draw the line?

Shops have to follow various rules about how much their products are allowed to stray from the weight stated on the pack. The most straightforward one is that no single pack can be underweight by a certain amount. How much depends on how big the pack is – smaller packs are given less margin for error – but for products between 100-200g, like most packs of smoked salmon, it’s 9%, so the Tesco salmon was just outside this margin.

When we took our findings to Tesco, it told us that:

‘Our records show that the weight of the products tested conformed to industry standards. It’s not uncommon for some of the oil in smoked salmon to transfer to the packaging while on the shelf.’

But there were other packs we bought that were also underweight but didn’t fall outside of the margin for error, such as a ‘200g’ pack that actually weighed 189g. I’d be pretty annoyed if I found out I was getting short-changed like that on my shopping – but at the same time, it’s impossible to have everything weigh exactly the same down to a single gram, so I can understand that there’s a need for a margin for error.

Have you bought food that weighs less than it should? Do you think the rules on weights are tough enough?


It’s impossible accurately to check-weigh packaged food unless you know the weight of the packaging but if the total weight including the packaging is on or under the declared weight of the foodstuff then you know there’s a shortfall. Unfortunately, few stores have scales or weighing machines near the refrigerators where packaged fresh foods are located.

The customer is never going to get more than the declared weight of product so the only balancing factor is the price. The supermarkets would argue that if they always had to match, or very nearly match, the declared weight then the unit price would be higher.

I bought one of the first digital kitchen scales that would measure to the nearest gram and recalibrated them so that they were accurate over a wide range of weights. I weighed all sorts of supermarket products and found that weights were either generous or very little short of the marked weight. That was quite a few years ago.

As John says, the packaging makes it difficult to check the weight of food but I’m tempted to put my scales in the shopping bag next time I go shopping and choose the heaviest pack of smoked salmon marked 200g.

That’s a good idea. I hope you get away with it and let us know the results.

When I get back from holiday I will try this late one evening, when I’m unlikely to attract the attention of staff in Tesco. I have checked a few products at home today and have not found a problem.

I have been busy with my scales and found some variation in weight, though the packaging makes it difficult to be certain about the weight of the contents. At home, where I have been able to check the weight properly, I have found some items that are slightly underweight but not seriously. On average I am getting a little more than I pay for.

I believe supermarkets of a certain size
are required by law to provide weighing
scales for use by their customers and what
is equally as important is such scales
provided must be accurate. Many a time
I’ve found purchased items weighing less
than specified when I take them home
weighing on my own highly accurate
electronic weighing scales.

Generally I avoid retailers that do not provide
such weighing scales for customers’ use.

Hi Argonaut – Brilliant! That’s almost a sonnet in form!

There’s usually a spring balance dial scale in the fruit and veg section but it might not be accurate enough to register on a small product [although for 200g it should be a reasonably good indicator of deficiency]. I find there’s usually a few grams of dirt in the bowl of these scales and I have sometimes had to complain at the lack of cleanliness of this apparatus that is required to be provided for customers’ benfit. The deli and other specialist sections usually have electronic digital weighing machines on the counter that they might let you check something on.

Thank you, John… you’re much too kind.

1. Like some other products, prepacked food could show gross weight (including packaging) and net weight (contents only). If you have digital scales you could then check if their is suspicion of underweight product.
2. If I buy 200g of something loose, it would be weighed for me and I would not receive less – assuming weights and measures have checked the scales. So why should not pre-packed food contain the amount shown on the package as a minimum? 9 % shortfall means you pay 10% more than you expect for what you get.
3. If the price tag shows £/100g, and there is a weight shortfall, does this not contravene trades description if the total price shown is for the assumed (higher) weight?

It’s smoked herring, not salmon, for us in these austere times. So I thought I’d check today’s breakfast. An M&S prepacked pair of Arbroath kippers with butter. The pack said 230g, 87% kipper (=200g), 13% butter (=30g). Actual weight – kippers 240g, butter 30g. 20% more kipper than it said. I wonder how M&S and Waitrose compare with the big 4. Will members’ scales be out in force?

One cause of this issue may be the way a lot of pre-packed food is marketted. Packs seem to be sold at set weights – 100g, 200g etc – when there is bound to be a variation in content weight. You can’t get exactly that amount from sliced smoked salmon, ham, etc – there is bound to be variation. So either put on the exact weight and charge each pack accordingly, or make the declared weight the minimum. The way fish and meat is packageds (my kippers were double sealed) I would have thought would be unlikely to lead to weight loss in strorage.

I’m pleased Which? is taking up this issue. I do a lot of baking and I’d noticed that packs of butter which should have been enough to make a dish were insufficient for the recipe *if* I measured out the weight on my scales. I was prepared to put it down to my scales but now I’m not sure – it’s happened on several occasions.
In a similar vein, Which? might also look at laundry liquids and if they’ve been watered down. Persil now requires more than a cap per wash for us whereas previously it was one cap. Why? Unless it hasn’t changed and Unilever et all are simply trying to get us to use more product per wash?

It’s worth checking that your scales are correct. I once bought expensive digital scales and found they were very inaccurate.

How much laundry liquid you need can depend a lot on the hardness of the water. That can vary according to the source of the water. My water has gradually become softer over the years, so I need less detergent. Detergent manufacturers are well known for recommending use of more than is needed.

Our scales were checked and found them surprisingly good. I’ve also found them pretty linear – used for counting sheets of card when I’m printing moderate quantities.
SR – checked our M&S butter and found them spot on. So as wavechange suggests could be worth checking. Good for cholesterol if you use less butter.

James says:
23 October 2012

Packs of nine halloween penguins are being sold in Tesco and Sainsburys claiming to be 24gms each by the supermarkets but have shrunk to 20gms. Interestingly I cannot see a weight anywhere on the packets.

All this reminds me of the reduction made to the milk cartons. So that 2×1.5L @50pcost £1.
Then they reduced the volume to 1L@50p, so the 3L then cost £1:50. A very nasty price rise of 50%.I keep seeing this tactic on other products. And its an increase in the use of packaging.Completely against the spirit of the EU directive to increase recycling. Why make something less green?

The salmon packs…well if they can get 80% of them under weight, and within the legal margin, then they can be more accurate than most people think. In other words, the margin should be reduced to say, less than 5%. Or simply say, nothing underweight is allowed and the price takes this into account. Supermarkets will not want that method, but it would be a fair way to do it for customers, and its a fair way to make price comparisons.

In the past supermarkets have managed to persuade the legislators ( MP’s ) to change the proposed laws, to make them useless, and evade the purpose.



I bought a 100g packet of Tesco ground almonds as it was the correct measure to make macarons. When I got home the packet only weighed 88g. Good job I had some more at home to make up the weight!

Jelunga says:
25 October 2012

I recentky bought a pack of Morrisons Smoked Salmon. I removed the wrapper and checked the weight of the packing. The contents were over 15% underweight. To give Morrisons a littke credit, when I reported this they did send gift vouchers with a value much greater than the shortfall.
Lets remove the stupid E symbol and go back to the Weights and Measures Act (1983 maybe?) and not allow ANY short weight sales.

If you are sure your scales are correct you could report this to your Trading Standards and inform the supermarket. It may make them more careful in checking their suppliers, or their own standards and policy.

Robin Ekblom says:
25 October 2012

One small thing which makes me question your findings is that in the accompanying photo there is an amount of salmon in the scale tray but the dial reads zero!

Thanks Robin, nicely spotted… we can assure you that the findings were accurate, though our picture demonstration may not be. 🙂

Jacky says:
28 October 2012

For months now Tesco have varied the weights of their mature and extra mature cheese whilst continuing to charge the same price – whilst annoying (and a little sneaky!) they do advertise the 450g/500g clearly.

What I did notice was that when they reduced the packs to 450g they never actually weighed as much as 450g – usually the packs are 440g or below. I buy several blocks a week and this has been going on for months (I’ve checked my scales – whilst not calibrated they are accurate enough).

However, I am happy to report that this week all 4 packs were a generous 460-480g….what a coincidence!

John E says:
28 October 2012

I bought a pre-packed piece of pork tenderloin at Marks and Spencer’s this week, and the stated weight on the pack was 0.480 grams. As we wanted to split the pack and use only part, we weighed the meat contents and found that it weighed 0.396 grams, approximately 20% less than stated on the package. A phone call to the shop brought the usual request to bring the package back, for a replacement or refund.

I support the suggestion that Which should consider some further work and a campaign on this issue, As I was shocked to discover such a discrepancy and now wonder how often this is happening as I rarely weight the contents of pre-package fresh food.

Clarinet2 says:
1 November 2012

I have a gripe with 400g packs of pineapple pieces from Sainsburys and Asda. If you try and weigh out 100g each for 4 people there is always a shortfall. I contacted Sainsburys about it but nothing has changed.

Conor says:
4 November 2012

I have hads the same problem with tinned tuna. I was amazed at how little tuna there is in a tin of Tuna Chunks in Sunflower Oil (John West) compared to what I remember a few years back. So I started weighing the drained contents. I found that on average over about 3 tins they had a drained weight of about 110g each when the tin says that it should contain 130g drained weight. I haven’t had time or the dedication to check other tins but I am sure this is another rip-off area.

Nauwol says:
17 May 2013

John West Tuna Chunks in Brine, 160g e, 112g drained weight. Drained the contents and weighed them. Result: 77g.
However Nutritional value on the tin implies 112g of quality tuna, not a mixture of 77g tuna and 35g of water.
30% less content than claimed. That cannot be legal.
Looking at other forums on the internet, John West seems to have a bit of a reputation for this. Is this the next food scandal in the making?
Does anyone know how one might get Trading Standards to get involved?

Which? Why not nominate a small range of specific products that members have complained about and ask more members to weigh what they buy? It depends upon accuracy of your scales – you can check by weighing something of similar known weight. Several coins, for example – £1 coin = 9.5 gramme, £2 = 12g (or, as times are hard, 10p = 6.5g). We might find whether the problem is widespread or isolated.

windandrain says:
6 November 2012

I regually buy the packs of frozen Tesco Haddock and kept telling myself I was sure the contents were not as much as they used to be, but, when you are rushing to shop and then rushing to get a meal cooked on time, you don’t stop to weigh an item, as it should be as it states the weight on the packet, but, it is not. I took some pictures this time in case they are needed, my pack of haddock pieces should weigh up to 477g or 450g with liquid ice or something it said, was removed and there was not any dribble of water to pour away from defrosting, but when I remembered to weigh them I had already dusted them in flour. The weight is about 390 g. I am allowing for my scales being in lbs and oz, but even so that is a big difference. I am wondering if the bags are lighter to make up for the special offer of 2 for think it was £6 rather then £3.50 each, so I can only assume that the so called special offer is nothing of the sort and I am paying exactly what the fish is normally priced at. So are all fish products like this and what about other foods.

I recently purchased 12 packs of ‘Bleiker’s Kipper Fillets 250G, with Butter’, direct from the Company. Each pack states additionally at the bottom, ‘250G’ in large print.
Ambiguous to say the least. The first statement implies that the kipper fillets weigh 250G, with the butter being in addition. But the second statement refers to the total contents.
However, on weighing all the packs unopened the smallest was 230G and the heaviest was 245G. Weight of an empty pack was 5G.
I have sent an email to the company to which they have replied saying they have passed it to their quality control manager.
Being a member of Which? Legal Service, Matt, is this a matter I should take up with them for their advice?