Skip to content
CiderHQ
Search

Storage

Storing bag-in-box and keg

How should bag-in-box and kegged cider be stored, and how long do they last unopened?

In short

A bag-in-box has a shorter unopened life than a bottle of the same cider, because the laminated pouch and the tap admit oxygen slowly but continuously; three to six months from filling is a typical working expectation, and warmth shortens it sharply.

A stainless keg is effectively impermeable, so a keg of pasteurised or filtered cider keeps for months to over a year; an unpasteurised keg is limited instead by its microbiology.

Both formats want the same conditions as bottles — cool, dark, stable — with the additional requirement that a bag-in-box should be kept flat, unpunctured and off the floor.

Why the container is the limiting factor

Glass is essentially impermeable to oxygen; whatever reaches the cider in a bottle comes through the closure. A bag-in-box pouch is a multi-layer plastic and metallised film, and while it is far better than plain plastic it is not glass: oxygen crosses it slowly across the whole area of the bag, and the tap assembly is a further route.

That is why the same cider has a shorter stated life in a box than in a bottle, and why box dates are usually given in months rather than years. It is also why a box that has been folded, dented, dropped or stacked under weight is a worse container than one that has not: creasing the laminate can compromise the barrier layers.

Stainless steel kegs are the opposite case. A sealed keg admits essentially no oxygen, and a filtered or pasteurised cider in one is very stable. What limits an unpasteurised keg is not oxygen but whatever organisms are in it, and a keg of live cider stored warm will continue to change.

Conditions

Storage of unopened bulk containers
FormatUnopened working lifeStorage requirementChief risk
Bag-in-box, still cider3–6 months from fillingCool and dark; flat, upright, not stacked heavilyOxygen ingress through pouch and tap
PolypinWeeks to a few monthsCool; supported so the container is not stressedPermeability and seam failure
Stainless keg, filtered or pasteurisedMany months to over a yearCool; upright; protect the couplerLittle, while sealed
Stainless keg, unpasteurisedWeeks to monthsCold storage strongly preferredContinued fermentation or spoilage; pressure build-up
Wooden caskShort; days to weeks after fillingCool and damp so the wood does not shrinkLeakage, resident organisms, oxygen through the wood
An unpasteurised keg can build pressureWhere a keg contains live yeast and residual sugar, warmth can restart fermentation in a sealed vessel. Kegs are built for pressure and have relief arrangements, but a container that is fermenting when it was not supposed to should be moved cold and vented carefully by someone who knows the fitting, not opened casually.

Handling a bag-in-box before it is tapped

Cold chain and small producers

A great deal of small-producer still cider is sold unpasteurised and unfiltered in bag-in-box, which means it is a live product. It will continue to change in the box, and it is much more sensitive to temperature than a pasteurised commercial cider. A box of farmhouse cider left in a warm car for a day has been damaged in a way a bottle would not have been.

Producers who ship such cider generally state a short life and expect it to be kept cool, and where they give a keeping time it is better evidence than any general figure. Some will say plainly that the cider is intended to be drunk within weeks.

The corresponding advantage is that these ciders are usually being sold close to when they were made, and the format is an honest one for cider that was never meant to sit on a shelf.

Also answered on this page

Questions this page covers, so you can tell at a glance whether it is the one you want.

Related

What people ask next

Questions readers ask about the things this page mentions. Each one goes to the section that answers it rather than to a page written to receive the question.

Sources

What this page rests on. Where a source is marked as registered rather than read, CiderHQ is recording that the body is authoritative on the subject without claiming to have worked through the document itself. See our evidence policy for what each state means.