Some everyday products - from digestives to dishwashingtablets - have been getting steadily smaller for years, but it might not always be obvious, and the kicker is that often prices don't shrink along with pack sizes.
Eagle-eyed Which? members have beensending us examples of supermarketproducts they suspect have shrunk.We've done some digging into the datato see what's happening, as well asconsulting experts to find out what'sbehind all of this.
The most commonly mentioned productswere Colman's sauces. A lot of you noticedthey had reduced in size but felt you werestill paying about the same.
Our researchshows that Colman's horseradish saucewas downsized from 250ml (costing£1.45 but frequently on offer across thebig supermarkets at £1) to 136g.
The newsmaller size is hardly any cheaper, costing£1 to £1.20, and it's less likely to be on offer.
McVitie's made news last year by gettingon the front foot and announcing packreductions across its digestive biscuits range.
Regular Digestives packets shrunk from 500gto 400g, Digestives Lights from 400g to 300g,and the chocolate ones from 300g to 266g.Pladis, the multinational company thatowns McVitie's, attributed the change to therising cost of ingredients and changes in theexchange rate, which it was unable to absorbthrough the business.
It told us it had dropped the recommendedretail price (RRP) for plain Digestives from£1.25 to £1, but at Asda the packs were beingsold at £1 both before and after the shrink.At Tesco they were £1.10 before and £1 after- not a proportionate drop.
The 1kg pack of Ambrosia Devon Custardvanished from all stockists (Asda, Morrisons,Sainsbury's and Tesco) around November2017, to be replaced with a 750g pack.
It cost£1.85 at Morrisons and Sainsbury's beforeand after the change. At Tesco the 750g packwas actually more expensive: £2 instead of£1.65 for the kilo size.
Premier Foods, which owns Ambrosia,pointed out that it had 'simplified the range'by eliminating both the 500g and 1kg packs and replacing them with the 750g pack.
But the price remained around what it had been for 1kg, rather than halfway between the two. So even taking into account the price per gram for a 500g pack, everyone is being forced to pay more for less.
The larger pack of Doritos was being sold for £1 both before and after the shrink at retailers including Asda.
A spokesperson for PepsiCo, which owns Doritos, told us: 'Like many businesses, we have changed the size of some of our products due to a number of factors impacting the cost of producing them.' PepsiCo said that it clearly labels packs and reviews it ranges regularly, and emphasised that prices are at the discretion of retailers.
A couple of members rightly noticed when restocking Bisto that the container suddenly appeared quite diminutive, and it had indeed shrunk to 190g from 300g.
Premier Foods, the owner of Bisto, told us it had dropped the RRP. But this still leaves customers paying more per 100g compared with the old, larger size.
Ecover admitted that it did not change the price or alert consumers to the change in size of its washing-up liquid, but it told us'the key change we did make was upgrading the bottle to be made from 100% post-consumer recycled (PCR) plastic because we believe in setting new standards of sustainability in the category'.
When we looked at shrinking products afew years ago, we found the 70 pack of FairyAll in One Lemon dishwasher tablets hadshrunk down to 67 tablets. It has now droppedagain to 60 capsules at some supermarkets.
Procter & Gamble, the owner of Fairy,told us that pack-size changes were dueto a combination of factors to do with itsresearch and development budget, which had - it claims - resulted in a better product.You can consult our to find out how we scored it.
A spokesperson forPurina - which owns Felix - pointed tosimilar reasoning around the cost ofmanufacturing. It hadn't dropped theRRP, but argued that this figure isn't atrue reflection of what the consumer pays,because of the promotional mechanicsbehind shelf price. Purina said that thesmaller 40 pack is regularly on offer for £10.
Purina's argument goes to show that when special offers are combined with changing pack sizes, it can be even harder to tell what you're getting for your money.
In the case of Felix, we found that thefull-price 40-sachet pack was regularly beingsold for £12.49 at Waitrose, compared with£12 for the larger 44 pack. At Tesco thesmaller pack is £12, compared with £9 to £12for the larger pack.
At Morrisons, the smallerpack was introduced at £10, then hiked upto £12.50 - albeit with regular discounts.
With Ambrosia custard, the larger sizewas introduced at Asda at a lower price of£1, but this gradually increased to £2, whilestill occasionally being discounted to £1.
Premier Foods - which owns Ambrosia and Bisto - also told us it had ramped up promotional activity for the launch of the smaller Bisto parsley sauce container at the time of the change.
A number of factors influenceshrinkflation, and manufacturers gave usvarying explanations. One common threadwas that the price youpay for their products is ultimately at thediscretion of individual retailers.
But ifmanufacturers aren't passing on reducedwholesale prices to supermarkets, thisposition is difficult to defend. Manufacturersdid not comment on wholesale prices.
The supermarkets and the British RetailConsortium told us that the sizing andpricing of products are regularly reviewedand are affected by a number of factors,including commercial negotiations, thecost of raw materials, and industry efforts to manage food waste and portion sizes.
Ratula Chakraborty, professor of businessmanagement at the University of EastAnglia, says that 'shrinking package sizesis a back-door way to increase prices withoutconsumers noticing.
'Studies show thatconsumers are four times more sensitiveto a price rise than a correspondingpackage size cut.' She notes that 'stealthypackage size cuts, typically 5-10%, willoften go unnoticed'.
Professor Chakraborty argues more needs tobe done to make things clear for consumers.She says: 'Quoting the unit price alongside theitem price isn't enough. Suppliers and retailersneed to be honest - and, if necessary, obligedby law to mark on their packages when the pack size has been reduced, for a period of at least one month.'
We investigated your submissions, fromsnacks to household cleaning supplies,and looked into pricing and weight dataover the past three years. We trackedprices from 2016 to 2019 using supermarketprice-comparison website MySupermarket,which gave us prices in monthlyincrements at Asda, Morrisons, Ocado,Sainsbury's, Tesco and Waitrose.