Concentration and speciality
Cryoextraction
Milling and pressing fruit that has frozen on the tree or in store, so the ice stays behind in the pomace and only concentrated juice runs from the press.
Also called frozen-fruit pressing, cryoextraction of frozen apples.
- Stage
- Concentration and speciality
- Traditional in
- Quebec
- What it most changes
- Sweetness up, acidity up
- Safety
- None recorded
What it is
Cryoextraction is the making of concentrated juice by letting the fruit itself freeze — on the tree, or gathered and held outdoors through hard frost — and then milling and pressing it while it is still frozen or only part-thawed. Ice remains locked in the pomace, and what runs from the press is the unfrozen fraction: a small volume carrying most of the fruit’s sugar, acid and phenolic material. It is one of the two recognised routes to an ice cider in Quebec, and it is not the same operation as freezing juice that has already been pressed.
Why it is used
- It concentrates juice without heat and without a membrane, so nothing is boiled off and no equipment stands between the fruit and the finished must.
- It makes the winter climate do the work, which suits growers in cold regions who can leave fruit hanging into deep frost rather than installing and running refrigeration capacity.
- It is one of the two methods admitted under the Quebec ice cider framework, so a producer working towards that designation has to choose deliberately between this route and cryoconcentration.
How it works
- When water in the fruit crystallises, solutes are excluded from the growing ice lattice and driven into a shrinking unfrozen phase, so sugar, malic acid and phenolics all rise together in whatever remains liquid.
- Pressing frozen or part-thawed pomace exploits that separation mechanically: the ice stays in the cheese while the concentrated liquid is expressed, so there is no separate decanting or fraction-collecting step.
- Repeated freeze–thaw cycles rupture cell walls and expose the flesh to air, so fruit that has hung through winter arrives at the mill soft, brown and already oxidative, carrying dried-fruit and cooked notes before fermentation has begun.
- Yield per tonne of fruit is low, and falls further the harder the fruit is frozen, because the more water is held as ice the less liquid there is to express — concentration is paid for directly in volume.
What it changes
The direction this step pushes the finished drink in, dimension by dimension. A direction, not a measurement: how far it moves depends on the juice, the temperature and how the step is carried out.
| Dimension | Direction | Why |
|---|---|---|
| Sweetness | Raises | Sugar is excluded from the ice phase and stays in the liquid fraction, so the juice reaching the vat carries far more fermentable sugar per litre than the same fruit pressed unfrozen; fermentation is arrested well before that sugar is used up. |
| Acidity | Raises | Malic acid concentrates on exactly the same principle as the sugar, which is what keeps a very sweet ice cider from reading as cloying — the two rise together rather than one at the expense of the other. |
| Body | Raises | Dissolved solids of every kind are concentrated into a smaller volume, so viscosity and mouth-filling weight increase measurably alongside the sugar. |
| Oxidative character | Raises | Freeze damage breaks cell walls while the fruit is still hanging, which brings polyphenol oxidase and its phenolic substrates together in the presence of air over a period of weeks rather than the minutes a normal milling allows. |
The chemistry and the organisms
What is actually being changed, and by what. Each entry says what that compound or organism does in cider generally; this page is one place it does it.
Compounds involved
Glucose
The sugar yeast takes first and the smallest of the three in apple juice, which is why the last sugar left in a slow ferment is almost never glucose.
Fructose
The dominant sugar of apple juice and the sweetest of the common sugars, which is why apple juice tastes sweeter than its total sugar figure implies and why a stuck ferment leaves sweetness behind.
Malic acid
The acid of apples, which supplies almost all the sharpness a cider has and, through pH, decides how vulnerable that cider is to everything that could spoil it.
Sorbitol
The unfermentable sugar alcohol that pears carry in quantity and apples carry only in trace, and the single reason a fully fermented perry keeps a sweetness a fully fermented cider cannot.
Where it is traditional
The places this step belongs to as a matter of practice. It is not a claim of exclusivity — a method can be traditional in one region and perfectly ordinary in another.
Styles it produces
Categories in which this step is characteristic or required. Some name it in their definition; for others it is simply how they have always been made.
Ice cider
Cider made from apple juice concentrated by freezing, fermented slowly and stopped while a large residual sugar remains, giving a dessert-strength drink of high acid and high sweetness.
Quebec ice cider
Ice cider made under Quebec’s reserved designation, which sets out how the juice may be concentrated, what may be added and what the finished product must contain.
Ice perry
Perry made from pear juice concentrated by freezing, in which the fruit’s unfermentable sorbitol adds to the residual sweetness the arrested ferment leaves behind.
More on cryoextraction
The distinction that decides everything about this record is where the freezing happens. In cryoextraction the fruit is frozen and pressed in that state, so the concentration takes place inside the apple and the ice never leaves the pomace. In cryoconcentration — the separate process described under ice concentration — whole juice is pressed first in the ordinary way, then frozen, and the concentrated fraction is drawn off from the ice. Quebec’s ice cider framework admits both, which is why two ciders carrying the same designation can differ so much in character: extraction delivers a must already marked by weeks of frost damage, browning and partial dehydration on the tree, while concentration starts from clean autumn juice and adds nothing but cold.
What the practitioner actually decides is how much crop to gamble. Fruit left hanging into midwinter is exposed to wind, birds, rot and thaw, and a mild season can leave a grower with neither a concentrated must nor a normal harvest. Cultivar matters as much as climate: apples that hold firmly to the spur and resist breakdown survive the wait, while those that drop or soften early do not. The pressing itself is demanding. Frozen pomace is abrasive, it does not build a stable cheese in the way autumn pomace does, and the pressure needed to move liquid through a part-frozen mass is hard on racks, cloths and hydraulics. Many producers work the fruit part-thawed as a compromise between yield and equipment life.
Done badly the process produces a must that is merely spoiled rather than concentrated. Fruit that thaws and refreezes repeatedly, or that sits wet on the orchard floor, accumulates rot organisms and the risk of patulin from Penicillium expansum, and no amount of subsequent concentration removes that. The resulting juice is also difficult to ferment: high osmotic pressure stresses the yeast, so a slow, cool, extended fermentation is the norm and stuck fermentations are common. Perry made this way is rarer still, because most perry pears break down quickly once frozen, which is part of why ice perry remains a small category beside ice cider even in the regions where both are made.
Related processes
Steps that sit alongside this one, replace it, or depend on it having been done.
Concentration and speciality
Ice concentration
Freezing pressed juice and drawing off the unfrozen fraction, so that water is removed as ice and everything else in the juice is left behind more concentrated.
Pressing
Hydraulic pressing
Pressing in which a pump drives fluid against a ram, so that a small pumped pressure becomes a large, controllable and repeatable load on the pomace.
Pressing
Pressing yield
The proportion of a fruit charge recovered as juice, and why a single headline figure for it is not a meaningful number.
Fermentation
Arrested fermentation
Deliberately halting a ferment while sugar remains, to obtain natural sweetness from the fruit rather than from an addition — and accepting the instability that follows.
Harvest
Fruit storage before milling
Holding a gathered crop between harvest and the mill, and managing what respiration, water loss and spoilage do to it while it waits.
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.
- How do you stop cider from fermenting — By removing the yeast, by chilling, by filtering it out, by pasteurising, or by a combination — and in practice a home maker cannot reliably stop a ferment mid-way with chemicals alone. Sorbate prevents yeast multiplying but will not stop an active ferment.
- What is pressing yield — Pressing yield is the proportion of fruit weight recovered as juice. It varies from under half on a poorly loaded basket press to around seventy per cent on a well-run rack-and-cloth or belt press.
- What is malic acid and why does it matter in cider — Malic acid is the acid of apples and supplies almost all the sharpness a cider has. It also sets pH, which decides how well sulphite works and how exposed the cider is to spoilage, so it does far more work than its taste suggests.
- What is ice cider — Ice cider is made by concentrating apple juice by freezing before fermentation, so that the ferment starts from a very high sugar level and stops sweet. It is a Quebec speciality with a protected definition there.
- Which sugar is most of the sugar in apple juice — Fructose, by a long way. Apple juice carries roughly twice as much fructose as glucose, with a smaller amount of sucrose, and fructose is the sweetest of the three on the tongue.
- Why is sorbitol important in perry — Sorbitol is a sugar alcohol that pears carry in quantity and that Saccharomyces cannot ferment. It passes through the whole fermentation untouched, so a perry can taste sweet while being dry by measurement.
Where to go next
- How cider is made — The whole sequence, stage by stage, with the choices open at each one.
- Cider science — The chemistry and microbiology the methods on this page rest on.
- Troubleshooting — What goes wrong, how to recognise it, and whether it can be reversed.
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.
University of Vermont cider research
University of Vermont Extension · university · retrieved 2026-08-24
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.