Milk bag

A milk bag in Ontario, Canada

Bagged milk is common in eastern Canada. The innovation was introduced in 1967 by DuPont using European equipment. The new packaging quickly found favour with the domestic dairy industry, being lighter and less fragile than glass bottles. However, the consumer public preferred plastic jugs for years, but largely accepted the new containers in certain regions in the 1970s. A major reason for that shift was with the national conversion to the metric system, which was easier to adjust to on production with bags, while doing the same for jugs required entire systems to be wholly redesigned.[2] Regulation in Ontario that required retailers to collect a deposit on milk jugs, but not bags, also motivated the practice.[3]

Milk bags are sold in parts of central Canada, Ontario, Quebec and the Maritimes, but not widely sold in western Canada, and Newfoundland and Labrador.[2] Three bags are sold together in a larger bag containing a total of 4 L (7 imp pt) of milk. The bags are not sold individually, and are either not labelled at all or labelled with only the expiry date, the lot number and sometimes the type of milk contained in the bag. The three-bag 4 L (7 imp pt) package is the largest normally sold at retail, with the lowest unit price. Some convenience store chains offer 4 L (7 imp pt) plastic jugs instead of milk bags, even in eastern Canada. Two accessories are commonly associated with Canadian milk bags — pitchers and bag openers. The key-shaped bag opener with a clip and a magnet was invented in Toronto in 1979.[4] These bag openers are a common type of refrigerator magnet, although the bags can be opened with scissors or knives. Large milk bags inside corrugated boxes (bag-in-box) are often used in milk dispensers at schools and institutions.

In urban parts of India, milk is most commonly sold in 0.5-litre and 1-litre bags.

In Israel, milk in a bag is the most common type of packaging for milk. They became the standard form of milk packaging in the 1960s, with the discontinuation of glass bottles. In Israel, the milk bag is a regulated product, which means that its price is controlled by the state. Therefore, there are price differences between the milk bags and the other alternatives available for marketing milk — plastic bottles or milk cartons. Due to the price differences, a relationship was observed between the socioeconomic status of the consumer and the type of milk container that they customarily purchased. The higher the socio-economic status of the purchaser, the more likely they are to buy milk in cartons rather than in bags, despite the higher price of cartons. Based on these differences, Network Blue Square created a way to measure the socioeconomic status of an area based on the sales ratio of milk cartons versus bagged milk. The higher the ratio of the former to the latter, the higher the status of the region in Israel.[5] For religious Jews, opening a bag of milk can be considered problematic on Shabbat, because the action requires cutting. Israel's interior minister has used empty milk bags in the Knesset, as props to complain about price-hikes in the cost of milk.[6]

In Mexico, assistance programs and prior welfare and government social programs distribute milk in bags (1 l (1.8 imp pt) per bag) at very low prices.[7]

Milk bags are also commonly used in Colombia, Ecuador, Argentina, Brazil, and Uruguay.[8]

In the United Kingdom, Sainsbury's began a pilot experiment on distributing milk in bags in 2008 in conjunction with Dairy Crest.[9] It was originally targeted at 35 stores at the same price as a regular 2-imperial-pint (1.1 l) plastic bottle of milk,[10] the product was expanded through the North of England nationwide in 2010 at which point the bags retailed at a discounted price compared to traditional containers.[11] In the UK, the bags are usually used in conjunction with a specialized plastic jug. The bag fits snugly inside the jug, one corner of the bag is secured under a bar at the front of the jug, and as the lid is closed the bag is pierced and a spout slides into the hole, maintaining freshness and allowing the milk to be easily poured. Doorstep deliveries in the United Kingdom are normally associated with traditional glass milk bottles, but the Dairy Crest/Milk & More service also deliver milk bags, and sell Jug-It brand plastic jugs specially designed to hold the milk bags. After lengthy negotiations, Milk & More was bought by dairy giant Müller from Dairy Crest in December 2015 and sales of the Jug-It plastic bags ceased.[12]

Dairies in the United States used the bags in the 1980s, but today are confined mainly to regional convenience store chains with in-house dairies, such as Kwik Trip in the Upper Midwest and other boutique dairies.