Milk containers routinely underfilled

Fair_deal

Has anyone noticed that milk containers in supermarkets are routinely underfilled? As a specific example, I have, over the last 6-months, routinely purchased 4-pints of milk at Lidl and, despite on each occasion choosing the best available on the rack (in terms of filled volume) I have yet to find one that is filled to the marked line on the container. After careful calibration and measurement, the underfill is usually in the range of two to three percent. Others on the rack will be underfilled by a greater amount. Complaints to Lidl are acknowledged by a coupon for a free bottle at my next shop. I have contacted my local Trading Standards office but there is no feedback. Is this a sneaky way to increase corporate profit and add to food shop inflation? The extra 5 pence earned on each carton times the millions of cartons sold daily surely adds up.

Alderbank

How are you measuring the volume of milk in each pack?

I wouldn't attach any value at all to the printed line on the carton. Ordinary domestic kitchen equipment like measuring jugs and digital scales don't measure to the precision and repeatability you need.

Isthisforreal99

I think the amount of people that care, or even notice, or have nothing better to do is less than 1%.

Woodstok2000

If you're buying milk in single use containers in the UK you will be buying it by the litre, not the pint, so you will need to calibrate your measurements that way for true accuracy and avoiding conversion errors.

At that volume they will be packaging on the average system. it's only the average across a batch which has to be above the stated volume. A small number of cartons can be up to 1.5% below the stated volume, and no carton should be more than double that (3%) below the stated volume.

Given your home measuring system probably has a similar margin of error, and it's going to be impossible to get ALL the milk out of the carton, this doesn't sound like a major issue.

A 3% underfill has cost you about 5p.

flaneurs_lobster

Pretty much anything (foodstuffs and otherwise) that is sold pre packaged by weight/volume uses the 'average quantity system' where the actual amount can vary over/under the nominal stated amount by a defined tolerance.

There's a decent overview here

https://www.businesscompanion.info/en/quick-guides/weights-and-measures/packaged-goods-average-quantity

PS - it's why there's often a single small runty boiled sweet in a packet - makeweight to get the average up.

AssemblyGMX

I hope this post can be seen as related. If not, I apologize.

Lidl 4 pints of milk, for a good while now, has cost exactly the same as M&S.

A few weeks back the price, overnight, because I had been there the day before, jumped by 10 pence (marked as "Good value"!) in M&S.

It is still 10 pence more in M&S than in Lidl - and in other supermarkets.

10 pence, for some of us, is a big jump for an essential food item.

I no longer buy milk in M&S. It's a pity because I used to buy my milk at M&S when buying reduced price yellow stickered items in their food hall.

subjecttocontract

It would seem to me that the important lesson to learn from this post is.......buy your milk from Lidl, complain and receive a coupon for free milk. The result is you get 2 for the price of 1. Win win all round.

flaneurs_lobster

It would seem to me that the important lesson to learn from this post is.......buy your milk in Tetra Paks, can't see how much you are being short-measured so nothing to worry about.

MyRealNameToo

https://forums.moneysavingexpert.com/discussion/comment/82108792#Comment_82108792

Even with the average system there is still a minimum for a single unit, for "4 pints" each individual unit must have at least 2,203.8ml even if the average of a batch is within tolerance

The other question will be what temperature the OP is measuring it at? The regulations require the volume to be correct at 20C. If they are measuring at 4C instead of the regulation temperature then that explains 0.4% of the "missing" volume

subjecttocontract

https://forums.moneysavingexpert.com/discussion/comment/82108864#Comment_82108864

Yes but none of that will get you a 2 for 1 opportunity, after all, this is the MSE website.

QrizB

I don't know how much a UKAS-accredited lab would charge to provide a certified measurement of the contents of a bottle of milk, but I suspect it would be more than my household spends on milk in a year.