Is bag-in-box wine as good as wine from a bottle?

Bag-in-box is wine in a foil bag with a tap, packed in a cardboard box, usually holding 3 litres.

Three litres corresponds to four bottles of 0.75 litre, or about twenty glasses of 15 centilitres. The bag collapses as you pour, so no air takes the place of the wine.

Directive 2007/45/EC sets eight sizes for still wine between 100 and 1500 millilitres and five sizes for sparkling wine between 125 and 1500 millilitres. Above 1500 millilitres the size is not fixed, and that is where the 3 litre box falls.

An opened box lasts longer than an opened bottle, because no air gets back into the packaging when it is poured.

With a bottle, air gets in with every glass, and that oxygen makes the wine start to discolour. With a bag-in-box the volume of the bag simply shrinks.

It is not unlimited. The foil itself also lets oxygen through, and that continues once the box is open. Research in the Journal of Food Science showed that mainly time and temperature determine how fast the colour changes and how much sulphite disappears.

Glass blocks almost all oxygen, foil does not, and it is precisely the amount of oxygen that determines how long wine keeps well.

The Australian AWRI reckons for bottled wine with about 27 months at less than 1.0 milligram of oxygen per litre in the package, about 8 months between 1.0 and 3.0 milligrams, and about 6 months above that.

For a box, that means: buy what you will drink within a reasonable time, and store it cool and dark.

Wines that are drunk young lend themselves to a box, because the packaging is not made to age for years.

Maturation in the bottle requires packaging that keeps oxygen out almost entirely and that stays the same for years. A box is intended for use within a short time, for example on a long afternoon in the garden or at a party.

In Bathmen the wine is in bottles, from small bottles to bottles of several litres. If you are looking for wine for a group, we will work out together how many glasses you need.

Store a box cool, dark and upright, and keep to the date on the packaging.

Heat speeds up the reactions that change the colour and break down the sulphite. The 2009 study compared storage temperatures of 22, 35 and 45 degrees for this; the higher the temperature, the faster the decay.

Storing it upright keeps the tap clean and prevents leakage along the tap. After use, put the box back in the fridge if you serve it chilled.