Equipment
Plastic vessels and what "food-grade" actually means
Can I ferment cider in a plastic barrel, and how do I know it is safe?
In short
Plastic fermenters are usually high-density polyethylene, polypropylene or, for carboys, polyethylene terephthalate. All three are used throughout the food industry and none of them are a problem in themselves.
What matters is whether the specific container was manufactured for food contact, using approved polymers and additives, and whether it has only ever held food. A drum of the right polymer that previously held a chemical is not made food-safe by washing it.
The two real risks are taint carried by the plastic and oxygen crossing the wall over long storage. Both are manageable if the vessel is chosen and used with those risks in mind.
What "food-grade" means and how to check
Food-contact materials are regulated: in the UK and EU, plastics intended for food contact must comply with the relevant food-contact materials legislation, use only authorised substances, and be supplied with a declaration of conformity. Compliant containers usually carry a symbol of a glass and fork, or a statement of compliance, moulded or printed on them.
The moulded recycling triangle with a number in it is not a food-safety mark. It identifies the polymer for recycling purposes and says nothing about the additives, the pigments, the release agents or the previous contents. A drum marked with the polyethylene code may be perfectly suitable or entirely unsuitable, and the code cannot distinguish them.
Second-hand drums are the commonest source of trouble. A drum that held a food product — fruit concentrate, brine, olives, glucose syrup — and can be identified as such is normally fine after thorough cleaning. A drum whose previous contents are unknown, or which held anything non-food, should not be used, and no amount of scrubbing changes that: solvents and aromatic compounds partition into polyethylene and leach back out into an alcoholic liquid for years.
Taint
Polyethylene is a good solvent for many small organic molecules. That is the physical basis of plastic taint: compounds absorbed into the wall diffuse back into a liquid that is a better solvent for them than water is, and ethanol makes cider a much better solvent than the juice was. A container that smells of nothing when dry can taint a cider after months of contact.
The same mechanism means fermenters acquire a history. A plastic vessel used for a heavily hopped or spiced batch, or one that has held a spoiled cider, may carry that character forward. Serious users keep dedicated vessels for flavoured batches.
Scratches are the other issue. Polyethylene is soft, and every scrub with an abrasive pad leaves grooves that hold soil and organisms below the reach of a sanitiser. Plastic vessels are cleaned with soft cloths and chemistry, and are retired when the interior is visibly scored.
Oxygen through the wall
Polyethylene and polypropylene are permeable to oxygen. The rate is low, but it is not zero, and it scales with surface area and with time. For a primary ferment of a few weeks this is irrelevant — the carbon dioxide leaving the vessel vastly outweighs anything coming in. For maturation over a year it is not irrelevant, and cider held long-term in thin-walled plastic will oxidise measurably faster than the same cider in glass or steel.
The practical rule most producers arrive at is: plastic for fermentation and short-term holding, glass, steel or wood for extended maturation. Thicker-walled vessels and those with a barrier layer perform better, and an intermediate bulk container in a metal cage is thicker-walled than a thin food drum.
Light is a related consideration. Translucent white or natural polyethylene passes light, and cider is susceptible to light-induced changes. A vessel that lets light through belongs in the dark.
Choosing and fitting out a plastic vessel
- Buy new food-grade, or buy second-hand with a documented and acceptable previous food use; do not gamble.
- Prefer a wide opening. A vessel that cannot be reached into cannot be cleaned or inspected.
- Fit a bulkhead tap only if it is a food-grade fitting with a cleanable bore; a cheap tap with a hidden cavity will be the dirtiest object in the cider house.
- Drill for a grommet and airlock rather than relying on a loose lid, and check that the lid gasket seals when clamped.
- Label the vessel with what it has held. Institutional memory about plastics is short.
Also answered on this page
Questions this page covers, so you can tell at a glance whether it is the one you want.
- Is it safe to ferment in a plastic barrel?
- What does food-grade plastic mean?
- Can I use an old chemical drum for cider?
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.
- What equipment do i actually need to make cider at home — At kitchen scale, most people start with bought juice and a demijohn, because that removes the two hardest problems — milling and pressing — and leaves the fermentation to be learned on its own.
- What vessel should i ferment cider in, and does the shape matter — The material question comes down to three properties: how much oxygen crosses the wall, whether the vessel adds or absorbs flavour, and whether the surface can genuinely be cleaned and sanitised.
- How do i sterilise cider bottles — Wash them clean first, then sanitise with a no-rinse sanitiser or a sulphite solution, and fill while still wet with it. Bottles that look clean but have dried deposits inside are the usual source of bottle spoilage.
- Is a glass demijohn a good vessel for making cider
- What is oxidation in cider
- What should i ferment cider in — Anything inert, cleanable and closable: glass demijohns, food-grade plastic, stainless steel, or a wooden cask if you can keep it sound. Vessel shape and material change how much oxygen the cider sees and how fast it clears.
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.
National Association of Cider Makers
NACM · specialist organisation · retrieved 2026-08-24
The UK trade association. Useful for industry-agreed definitions and for the voluntary labelling standards its members work to. A trade body has an interest in how its product is described, so CiderHQ cites it for what the industry says about itself rather than for neutral scientific claims.
The New Cider Maker’s Handbook: A Comprehensive Guide for Craft Producers
Claude Jolicoeur, Chelsea Green Publishing, 2013. ISBN 9781603584739 · reference work · bibliographic record verified, not opened 2026-08-25
Bibliographic record verified on 2026-08-25 against the Open Library union catalogue: Chelsea Green Publishing, 2013, ISBN 9781603584739, one edition recorded. That establishes the citation points at a real book in a stated edition, which is what a citation needs and is all it establishes. No copy was opened and nothing is quoted from it. The book itself is in print and not digitised in any open collection; where CiderHQ needs a figure from this territory it uses an accessible research source instead and says so.
Cider and perry production technical training material
Peter Mitchell / Cider and Perry Academy · reference work · registered as competent for this subject
Searched again on 2026-08-25 and it remains the one printed source here that a bibliographic check cannot fix, because it is not a published work with an edition. It is course material issued to participants of a training programme, so there is no catalogue record to verify, no ISBN, and no lawful public copy. Its state stays `registered` for that reason rather than through inattention.
Where to go next
- Cider making equipment — The rest of the equipment material, grouped by what each piece is for.
- How cider is made — The methods this equipment exists to carry out.
- Troubleshooting — The faults that are traced back to equipment and to cleaning.