I am not sure if it happens in other countries, but some provinces in Canada uses milk bags for 4L instead of jugs, or other containers. Anyone knows if there is an advantage of this over the other conventional method? Is it because it's supposed to be more consumer friendly?

Because of this you have to buy a special item called milk bag holder that's only used for this. It's an item made to solve a problem that shouldn't be there in the first place. But also now you have another thing to clean from time to time as milk drops can form all kinds of bad stuff in the holder. The most common ones can even cut your hand because of utilizing ridges at the top for no reason.

There are other gotchas like what you need to do to seal the hole temporarily, etc.

Is there a reasonable design decision for this or it is done just because?

This is how it looks:

enter image description here

  • I have never seen that in any place that I have lived or traveled to. It's quite original for me, risky, but original.
    – PatomaS
    Commented Mar 1, 2014 at 8:15
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    Germany once used milk bags instead of TetraPaks, but I didn't find milk bags anymore since ~2002.
    – Ray
    Commented Mar 1, 2014 at 15:57
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    @JoanVenge: laugh It's just a motor memory, awoken: standing there with a bag of milk lifted. You pick one bag from the bag/milk soup, pinching it at one corner, lifting it carefully as not to splatter milk over you. With all weight resting on one bottom corner, you try to figure out whether the milk dropping from it is from the outside or the inside - quickly, so you do not get stern words from the shopping courtesy police. Repeat for all corners.
    – peterchen
    Commented Mar 4, 2014 at 8:14
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    I'm voting to close this question as off-topic because it is about reasons products are designed a certain way for reasons other than UX.
    – DA01
    Commented May 8, 2015 at 5:24
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    While the ultimate answer may not be UX, the initial framing of the question is entirely framed from a usability perspective. "Why do I have to buy a 3rd party milk jug" vs. "Why not just design the handle into a plastic jug I buy" - being just one of the points brought up. Commented May 8, 2015 at 15:54

6 Answers 6


The Wikipedia article on Milk Bags point out the other countries they are common in. It also calls out the benefits (though not referenced):

Milk bags use less plastic than traditional milk jugs and are placed in reusable plastic pitchers. The bags themselves can also be washed out and re-used to carry sandwiches, or to freeze food (using a twist tie or rubber band for closure).

They contain less plastic than a milk jug, causing less environmental harm than milk jugs. Milk bags are more ideal from an environmental standpoint than paper milk cartons or glass milk bottles.

"Bucky," over at The West Virginia Blogger, asked his Canadian friend in 2008 and received several points, including:

  • The bags were actually adopted to reduce waste and other resources required to transport the milk.
  • The bags themselves are easy to sterilize and transport and some people even freeze their milk.
  • As well, the fact that you buy such a large amount usually means savings.

A comment in the above article by "sj" claims there is a 25-cent deposit on plastic jugs in Ontario, to help keep them out of landfills by discouraging people from buying them.

From Worthwhile Canadian Initiative, further evidence of overall cost is given:

there are a fair number of people in South Africa who don't have much money. Milk bags use less materials than jugs, so are cheaper to make. Some people are willing to pay for convenience, some people aren't.

Note the last paragraph, implying that bags are not more usable then jugs. Indeed, an update to the same blog post points out:

Update 1: Chris Auld wrote to Dan Wong of the BC Dairy Council and received this reply. Mr Wong explained that milk is not sold in bags in BC because of widespread cross-border shopping - consumers prefer milk sold in jugs, and be even more inclined to buy milk in the US if milk was not available in jugs in BC.

It appears that, according from the Dairy Council, consumers in Canada were willing to cross the border to America to buy jugs (likely at higher cost) for the convenience.

It would appear the the "design" decisions behind bagged milk is primarily for environmental and transportation reasons. The cost saving design of this is also of note, but unlikely to be the primary reason due many consumers willingness to spend more for convenience (i.e., jugs).


It's cheaper to ship them.

This is a case in which the monetary considerations often outweigh the usability considerations. Imagine the milk crates containing the packages.

Some big-box retailers in the US started using rectangular milk jugs rather than the ones with the angled tops. They're awful to pour because they're unbalanced.

Which of these do you think costs less to ship:

milk containers

  • I would like to have that rectangular milk jug :) I definitely agree that the standard milk jug is unbalanced and strains the wrist if you pour it with your arm in front of you. But how can you stack the plastic bags without them bursting? If you use square milk containers, then I wonder how much difference we are talking about.
    – Joan Venge
    Commented Feb 28, 2014 at 21:37
  • The rectangular containers are even more unbalanced. If I want to venture a guess on this, do I answer again? Anyway, my best bet is that the boxes contain cardboard dividers like in a 6-pack of bottles, with cardboard layers in between. Can't find any pictures, though.
    – SwankyLegg
    Commented Feb 28, 2014 at 21:50
  • To clarify, I was referring to the bags, not the milk jugs here.
    – SwankyLegg
    Commented Mar 1, 2014 at 18:39

Milk bags are pretty much all we've got here in Ontario. I understand that milk bags were adopted not because they are easier to use from the consumer's perspective, but because they are cheaper to manufacture and fill.

Still, they have many advantages from a UX perspective:

  • Milk bags are easier to handle and pour without spilling. If you've ever seen a small child struggle to pour a full 4L jug, you'll know what I mean. Individual bags are only 1.33 litres, so are quite light.

  • When pouring, the stream of milk does not go "glug-glug" as air is sucked back into the container, because air does not need to go back into the container. The bag is flexible, so it simply deforms. What's left when the bag is empty is an air-free bag with a few milk drops. These do not develop a smell in the garbage because the leftover milk is trapped in a bag that only has a pinky-sized hole in one corner.

  • Milk bags take up much less room in the refrigerator. We have a drawer where we dump them in, and this gets filled with no leftover space wasted to air. If we had jugs, we wouldn't have room for anything else.

  • For a person with reasonably strong arms, it is easier to carry many bags of milk at once, compared to jugs, where the limiting factor is the ability to actually hold them all.

  • When it comes time to dispose of an empty bag, bags take up much less room in the trash/recycling bin than jugs, which are difficult to flatten.

Now what makes them worse, from a UX perspective:

  • They have the perception of fragility, so people are less likely to use or trust them.
  • They require a tool to cut the corner off (usually a cutter that clips to the pitcher, but scissors work too).
  • The individual bags are clear plastic with no labels, so once you remove them from the carrier bag, it's not obvious what kind of milk it is (whole, skim, 2%, organic, etc.), or the expiry date if it's not stamped on each bag (usually not). Some kinds of milk will come in different coloured translucent bags, though.
  • Not all municipalities recycle plastic bags, so consumers who think about this sort of thing might prefer to buy recyclable jugs.
  • You end up with little plastic corners all over the place that might be a choking hazard to children.

(It's a common misconception by some that milk bags leak or can burst. They do not. Over 20 years, I can remember only a couple incidents of leaking milk bags, and that was from dropping them on sharp gravel or pavement. If you drop a milk bag on the floor, it will not burst. Try doing that with a 4L jug. I did, and the results weren't very pleasant.

As for where to put the bag, you can use any old pitcher like the picture in Robyn's answer shows, but if bagged milk is all you buy, it makes sense to have a dedicated pitcher. Since milk bags do not leak, it follows that the milk pitcher will not develop smells. Our milk pitcher probably gets washed only every month or two.)

  • Interesting points in this answer.
    – PhillipW
    Commented Mar 8, 2017 at 23:03
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    I don't know why all the answers are focused in Canada. I live in Argentina, and that's the most common milk package (it's called sachet here). I agree with most of the points in this answer, but having working for milk companies, I can tell there's one main reason: price. Everything else (good or bad) is a consequence of the price saving and sometime cab be quite subjective, but price is something nobody can deny
    – Devin
    Commented Mar 9, 2017 at 2:47
  • @Devin: The answers are probably focused on Canada because SE's user base is largely English-speaking people from English-speaking countries. And I covered that point about price in my second sentence, but "price" doesn't really cover the UX angle, hence the rest of my answer.
    – user69458
    Commented Mar 9, 2017 at 21:37
  • @FighterJet, as I said, i agree with all your points, the comment was more directed to the whole corpus of answers
    – Devin
    Commented Mar 9, 2017 at 21:44

I heard that this is common in Canada. It seems quite fragile and almost a 100% guarantee of spilling when you open it. Not very good for immediate usability right there.

These types of containers are flexible enough that you can pack more of them in one box for shipping. When it's in the store, I imagine they could be stacked, saving lots of shelf room.

You may want to consider purchasing rectangular, thus space-saving containers to put your milk into for storage in your fridge.

  • And it's not even everywhere in Canada. Alberta didn't have it, Toronto and Montreal has it. I don't know about the others.
    – Joan Venge
    Commented Feb 28, 2014 at 21:02
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    They're actually very easy to open without spilling. You use scissors to cut one of the corners (after putting the bag in a jug).
    – Dean
    Commented Mar 1, 2014 at 7:13

I'd also note that in the food service industry, refrigerated milk dispensers ("cows") are generally loaded with a bag these days. Since the bag includes a tube that serves as the nozzle, and the dispensing valve simply pinches off that tube, this makes the entire system a sterile, disposable container rather than requiring a great deal of effort to clean the cow on a regular basis.


I live in Arnprior, near Ottawa, Ont.

Milk bags are a breeze to use, not sure what the hubbub is. You simply cut one corner once you have dropped the bag into the jug; not decanting the milk out of the bag into the jug. It pours perfectly, and actually goes bad less frequently than carton or jug milk, as the bags are 1 liter, whereas both others are often in 2 liter format. Also, the bag in jug is not as heavy or awkward as the cartons & plastic jugs while pouring.

That being said, we all drink far too much milk in Canada, but it's a hard habit to break...

picture of a milk bag in a cup

  • Yeah but it's not all of Canada that uses milk bags and just like in your picture you have to use a different instrument to store the milk which is unnecessary.
    – Joan Venge
    Commented May 10, 2015 at 14:35

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