The most honest object in a juice operation is the one nobody photographs.

At the end of a pressing cycle the press opens, and what comes out first is not juice. It is a slab of compressed fruit solids — skins, seed fragments, collapsed cell walls, the spent pulp the trade calls pomace. It is dry enough to break apart in your hands. It smells of apple for about an hour and then of nothing much at all. And it is heavy: in a 2019 Polish study of apple pressing, juice yields across three varieties and two press types ranged from 61.9% to 71.6% of the fruit that went in [1]. Do the arithmetic on the low end and roughly a third of the harvest leaves the building as that cake.

That is the part of cold pressing nobody puts on a label. It is also the honest place to start on a question we get asked often, usually with a note of scepticism: is cold pressing worth it, or is it a marketing word?

It is worth it — but not for the reason most brands give, and the evidence for that reason is genuinely weak. Here is the whole picture, including the parts that don’t flatter us.

What actually happens inside a press — and what it leaves behind

Strip away the language and juicing is one problem: fruit keeps its liquid inside cells, and you want it outside.

There are three broad ways to solve that. You can shred the fruit at high speed against a spinning mesh and let centrifugal force fling the juice out — the mechanism in most countertop juicers and in a good deal of industrial extraction. You can heat the fruit until the cell walls give up, which is what a steam juicer does. Or you can crush the fruit into a mash and then squeeze it, slowly, under mechanical pressure, until the liquid runs out through a cloth or a perforated wall.

That third method is cold pressing. The “cold” is not a refrigeration step and never was — it means no heat is applied to drive the extraction. A hydraulic basket press works at a few megapascals and room temperature. The fruit is never cooked; it is squeezed.

What that buys you is physics, not magic: less cellular shredding, less air whipped into the liquid, no thermal load during extraction. Whether those three things add up to a better glass of juice is exactly what the research has been arguing about — and the argument has not gone the way the industry expected.

The first cost: everything you leave behind

Pressing is inefficient, and how inefficient depends enormously on the fruit and the machine.

A 2024 comparison by Baykus and Unluturk put a household cold-press juicer against a centrifugal one on a pineapple-based blend and measured what came out. Cold pressing returned 92% of the pineapple as juice; centrifugal extraction returned 47% [2]. That gap is the strongest genuine argument for pressing: on soft, juice-heavy fruit, a press gets more out.

But the same paper found something less convenient. Total phenolic content came in at 867.25 mg GAE/L for the cold-pressed juice and 922 mg GAE/L for the centrifugal one — slightly higher in the centrifugal juice — and the DPPH radical-scavenging activity of the two was not significantly different [2]. More juice, not richer juice.

Press design matters too, and not always in the direction you’d guess. The 2019 apple study compared a hydraulic basket press running at 4.5 MPa against a twin-screw press. The screw press produced both the higher yield and juices with higher soluble solids, higher viscosity, higher total polyphenols and higher antioxidant activity than the basket press [1]. “Cold-pressed” covers both of those machines. They do not perform identically.

So the first cost is real fruit: every point of yield you don’t recover was grown, harvested, washed and paid for, then sent out as animal feed or compost. On a fruit like sea buckthorn — small, awkward, harvested by cutting and freezing whole branches — that is not a trivial loss.

The second cost: heat is not the only enemy

The standard story says heat is what damages juice. Heat is one thing that damages juice. Oxygen and the fruit’s own enzymes are another, and at the extraction step they are arguably the bigger threat.

Intact plant tissue keeps polyphenol oxidase — PPO — physically separated from the polyphenols it acts on. Rupture the cells violently and you introduce the enzyme, its substrate and atmospheric oxygen to each other at once. The result is enzymatic browning: the polyphenols are consumed, the colour goes brown, and the compounds you were trying to capture are gone before anyone has tasted anything.

A 2018 study by Park and colleagues in Bioscience, Biotechnology, and Biochemistry made this visible. Apple juice prepared in a high-speed blender showed polyphenol oxidase activity roughly 4.5 times higher than juice from a low-speed masticating juicer, and was visibly darker. The gentler method retained polyphenols and flavonoids at roughly double the concentration of the blender juice — because in the blender those compounds had been eaten by their own enzyme [3]. Note the comparison: a blender against a slow juicer, not a centrifugal juicer against an industrial press, and apples only. It shows a mechanism, not a universal ranking.

Still, the mechanism is the honest case for pressing. Not “cold pressing preserves nutrients” as a slogan, but something narrower and more defensible: slow mechanical extraction incorporates less oxygen and does less enzymatic damage during the minutes when the juice is most vulnerable.

The awkward study

Now the part that a juice company is not supposed to bring up.

In 2019, Khaksar, Assatarakul and Sirikantaramas published a paper in Heliyon with an unusually blunt subtitle: do cold-pressed juices harbor a superior nutritional quality and antioxidant capacity? They juiced pineapple, guava, white and red dragon fruit and carrot by three methods — a vertical cold-press juicer, a centrifugal juicer and a blender — and measured ascorbic acid, total phenolics, total carotenoids, and antioxidant capacity by both FRAP and DPPH [4].

They found no significant differences between the extraction methods on any of those measures. Their own conclusion, verbatim: “Our results strongly question the claim regarding the superior quality of cold-pressed juices” [4].

That is five fruits, one laboratory, and results reported as figures rather than tables, so it is not the last word. But it is a direct, well-designed test of the industry’s central marketing claim, and the claim did not survive it. Anyone selling cold-pressed juice on the promise of measurably more antioxidants per glass is making a claim the published evidence does not currently support.

The same paper produced a finding we think is more useful than the headline. Stored at room temperature — around 28 °C — the cold-pressed juices lost ascorbic acid, phenolics, carotenoids and antioxidant capacity significantly within 48 hours. Refrigerated, the same juices were essentially unchanged to day 5, began declining at day 6, and hit their lowest values at day 7 [4]. The extraction method turned out to matter far less than what happened next.

Where heat genuinely wins

If the case for cold pressing were simply “heat destroys things”, the food science literature would be a lot tidier than it is.

Heat destroys some things. In a 2015 study of sour cherry juice, four hours of sustained heating cost 18% of total anthocyanins at 70 °C and 38% at 90 °C in one cultivar, and 19% and 46% in a second [5]. But four hours is nothing like pasteurisation, which holds juice at temperature for seconds. A 2024 review collected the short-hold figures: sea buckthorn juice at 100 °C for 15 seconds lost 14.3% of its vitamin C and 20.5% of its carotenoids — while its total phenolic content rose 6.5% [6].

That last number is not a typo, and it points at the awkward truth: heat also creates access.

The clearest demonstration is in tomatoes. In 2002, Dewanto and colleagues heated tomatoes at 88 °C and measured what happened. Vitamin C fell from 0.76 to 0.54 µmol/g after 30 minutes — a loss of about 29%. But total antioxidant activity rose from 4.13 to 6.70 µmol/g, an increase of roughly 62%, and bioaccessible lycopene increased substantially [7]. Heat had wrecked one compound and liberated another. The paper’s title says it plainly: thermal processing enhances the nutritional value of tomatoes.

Human data points the same way. Gärtner, Stahl and Sies fed volunteers 23 mg of lycopene either as fresh tomatoes or as tomato paste, each with 15 g of corn oil, and measured the chylomicron response. Peak lycopene concentrations were 2.5-fold higher from the paste, and the area under the curve 3.8-fold higher [8]. Processed beat fresh, decisively, for that particular compound.

Even in berries the picture is mixed. A 2023 study of haskap — the berry behind Blue North — compared a steam juicer, a centrifugal juicer at 13,000 rpm, and a bladder wine press. Steam juicing came out clearly worst, with anthocyanins about a third lower than the other two methods. But the centrifugal juicer, not the press, gave the highest total phenolics and the highest DPPH antioxidant capacity — reported as roughly four times the antioxidant capacity of steam juicing and about 50% more than press juicing [9].

We sell pressed haskap juice. That study says a spinning blade beat our method on two of its measures. We would rather you heard that from us.

Pressing is not preserving — and this is the distinction that matters

Cold pressing is an extraction method, not a preservation method. It describes how juice was separated from the fruit — crushed and squeezed under mechanical pressure at room temperature — and says nothing about what happened afterwards. Pressed juice may still be untreated, high-pressure processed, or pasteurised.

Here is the confusion at the centre of almost every cold-pressed juice conversation, including some of our own past writing.

Cold pressing is an extraction method. It is not a preservation method. It describes how the liquid was separated from the fruit. It says nothing whatsoever about what happened in the twenty minutes, or the six months, afterwards.

This matters because untreated juice is a superb growth medium. The outbreak investigation published in Annals of Internal Medicine in 1999 identified 70 people infected with E. coli O157:H7 from unpasteurised commercial apple juice in 1996: 36% were hospitalised, 20% developed haemolytic uraemic syndrome, and one died. The apples were traced to an orchard where deer carried the same strain, and to a third lot containing decayed fruit; the authors concluded that the plant’s standard sanitation was not sufficient to eliminate the pathogen [10]. The US response was the juice HACCP rule, 21 CFR Part 120, published in January 2001, which requires processors to apply a treatment achieving a 5-log — hundred-thousand-fold — reduction in the pertinent pathogen, sustained across the product’s shelf life [11].

The EU took a different route. There is no European 5-log mandate and no juice-specific lethality requirement; the word “juice” does not appear in Regulation (EC) No 852/2004, which instead obliges every food business to operate a permanent HACCP-based procedure [12]. Instead, Regulation (EC) No 2073/2005 sets microbiological criteria that apply specifically to unpasteurised ready-to-eat fruit and vegetable juices — Salmonella not detected in 25 g as a food safety criterion, and E. coli limits of m = 100 and M = 1,000 cfu/g as a process hygiene criterion [13]. Unpasteurised juice is entirely legal in Europe. It is simply held to a measurable microbiological standard rather than a prescribed process.

So every juice you can buy has been through one of four fates after pressing: nothing at all, with a shelf life measured in days under refrigeration; high-pressure processing; thermal pasteurisation; or a thermal process sufficient for shelf stability at ambient temperature.

High-pressure processing is worth understanding because it is widely marketed as “raw”. A 2022 EFSA opinion sets out the industrial reality: pressures of 400–600 MPa are typical, with holding times of 1.5 to 6 minutes, and — the sentence that matters — non-thermal HPP treatment does not inactivate spores [14]. HPP is a pasteurisation, not a sterilisation. It is why HPP juice still lives in the chiller.

The honest position, then, is that pressing and preserving are two separate decisions, and a brand should be straight about both. If you want to go deeper on the preservation half, we wrote about what pasteurisation does and doesn’t do to juice and about why the pigments themselves are the point.

So why do we still do it

Because the defensible reasons are enough.

Pressing recovers more of the fruit, which is the difference between a viable product and an unviable one when the raw material is Latvian sea buckthorn rather than commodity concentrate. It introduces less oxygen and does less enzymatic damage in the minutes when juice is most fragile — a mechanism with direct experimental support [3]. It produces a juice whose flavour and body we prefer, which is a taste judgement and we will call it that. And it commits us to fruit good enough to press whole, because a press is unforgiving of poor raw material in a way that heat and concentrate are not.

What it does not do is put more vitamin C in your glass than a centrifugal juicer would [4]. We are not going to tell you otherwise in order to sell you a bottle of sea buckthorn juice.

What this will not do

Cold pressing will not make juice a substitute for fruit. Pressing removes the pomace, and the pomace is where most of the fibre was. Whole fruit remains the better choice and juice is a supplement to it, not a replacement.

It will not make juice a low-sugar drink. Pressing concentrates the fruit’s own sugars into a glass you can drink in ninety seconds. The sugar is intrinsic rather than added, but your bloodstream is not checking the paperwork.

It will not extend shelf life. If anything the opposite: gentler extraction leaves more of the fruit’s own enzymes intact, and the Heliyon data shows how quickly a cold-pressed juice degrades at room temperature — significantly within 48 hours [4]. Cold pressing buys you nothing at all if the bottle then sits warm.

And it will not turn juice into medicine. Under EU rules, vitamin C may be described as contributing to normal immune function, to the reduction of tiredness and fatigue, and to normal collagen formation [15] — a real and useful set of functions, and the whole of what can honestly be claimed. If you are pregnant, breastfeeding, taking anticoagulants, managing reflux, or on regular medication, speak to your doctor or pharmacist before adding a concentrated plant product to a daily routine — turmeric and grapefruit interact with common drugs, berry and sea buckthorn juices are acidic enough to matter with reflux, and any new plant is a new allergen for someone.

How to read a juice label this week

Four things tell you most of what there is to know, and none of them is the word “cold-pressed”.

Look at where it is stored, not what it says. A juice sitting on an ambient shelf has been heat-treated or is shelf-stable by some other validated process. A juice in the chiller has had less done to it. The fridge door is a more reliable signal than any front-of-pack claim.

Check for “not from concentrate”. This is a bigger difference than the extraction method. Concentrate has had water boiled out and put back — two thermal steps and a long storage period in between. We have written about that comparison specifically.

Read the ingredient list, and count. For a single-fruit juice it should say one thing. Added sugar, added water, added acidity regulators and added “natural flavourings” all tell you something about what the base juice was like.

Ignore “raw” as a safety signal. It is not a regulated term in the EU and it does not tell you whether the product was treated. HPP juice is routinely sold as raw, and HPP is a pasteurisation [14].

And if you want to test the flavour argument rather than take ours, put a single-ingredient pressing — a 100% aronia, a rosehip — beside the supermarket version of the same fruit. That is a sensory judgement, and the one kind of claim you can settle in your own kitchen.

The cake in the press is the honest accounting. It is a third of the fruit, and it is the price of a method that gets us the juice we want without cooking it — a method that, on the best current evidence, wins on yield, on oxidation, and on flavour, and does not win on antioxidants per glass. We would rather publish that arithmetic than a slogan. The berries were real, the press is real, and so is the cake.

Frequently asked questions

Is cold-pressed juice more nutritious than regular juice?

Not according to the strongest direct test. A 2019 Heliyon study juiced five fruits and vegetables by cold press, centrifugal juicer and blender, and found no significant differences in vitamin C, total phenolics, carotenoids or antioxidant capacity between the methods [4]. Cold pressing’s measurable advantages are in yield, oxidation during extraction, and flavour — not in antioxidants per glass.

Is cold-pressed juice pasteurised?

It depends entirely on the brand, because “cold-pressed” describes only how the juice was extracted, not how it was preserved. Pressed juice may be sold untreated and refrigerated for a few days, high-pressure processed, pasteurised and chilled, or heat-treated for ambient shelf life. Where the product is stored in the shop is a more reliable signal than the front-of-pack wording.

Does HPP juice count as raw?

It is widely marketed that way, but high-pressure processing is a pasteurisation. EFSA’s 2022 opinion describes typical industrial conditions of 400–600 MPa for 1.5 to 6 minutes and states that non-thermal HPP does not inactivate bacterial spores — which is why HPP juice still requires refrigeration [14].

What is pomace, and how much of the fruit becomes pomace?

Pomace is the compressed solid residue left in the press after juicing: skins, seeds and spent pulp. It is not measured directly in most studies, but it follows from yield. A 2019 apple-pressing study reported juice yields of 61.9% to 71.6% depending on variety and press type, which leaves roughly a third of the incoming fruit as pomace [1].

References

1. Wilczyński K, Kobus Z, Dziki D. Effect of press construction on yield and quality of apple juice. Sustainability. 2019;11(13):3630. doi:10.3390/su11133630
2. Baykuş G, Ünlütürk S. Cold pressed vs. centrifugal juice: comparison in terms of the juice yield, physicochemical and phytochemical properties. Food Science and Engineering. 2024;5(1):145–154. doi:10.37256/fse.5120243849
3. Park S-Y, Kang T-M, Kim M-J, Kim M-J. Enzymatic browning reaction of apple juices prepared using a blender and a low-speed masticating household juicer. Bioscience, Biotechnology, and Biochemistry. 2018;82(11):2000–2006. doi:10.1080/09168451.2018.1497943
4. Khaksar G, Assatarakul K, Sirikantaramas S. Effect of cold-pressed and normal centrifugal juicing on quality attributes of fresh juices: do cold-pressed juices harbor a superior nutritional quality and antioxidant capacity? Heliyon. 2019;5(6):e01917. doi:10.1016/j.heliyon.2019.e01917
5. Szalóki-Dorkó L, Végvári G, Ladányi M, Ficzek G, Stéger-Máté M. Degradation of anthocyanin content in sour cherry juice during heat treatment. Food Technology and Biotechnology. 2015;53(3):354–360. doi:10.17113/ftb.53.03.15.3931
6. Polak N, Kalisz S, Kruszewski B. High-temperature short-time and ultra-high-temperature processing of juices, nectars and beverages: influences on enzyme, microbial inactivation and retention of bioactive compounds. Applied Sciences. 2024;14(19):8978. doi:10.3390/app14198978
7. Dewanto V, Wu X, Adom KK, Liu RH. Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity. Journal of Agricultural and Food Chemistry. 2002;50(10):3010–3014. doi:10.1021/jf0115589
8. Gärtner C, Stahl W, Sies H. Lycopene is more bioavailable from tomato paste than from fresh tomatoes. The American Journal of Clinical Nutrition. 1997;66(1):116–122. doi:10.1093/ajcn/66.1.116
9. Wang Z, Svyantek A, Miller Z, Jarrett B, Kapus A. Haskap juicing method effects on haskap juice quality. Applied Sciences. 2023;13(19):10784. doi:10.3390/app131910784
10. Cody SH, Glynn MK, Farrar JA, et al. An outbreak of Escherichia coli O157:H7 infection from unpasteurized commercial apple juice. Annals of Internal Medicine. 1999;130(3):202–209. doi:10.7326/0003-4819-130-3-199902020-00005
11. US Food and Drug Administration. Hazard Analysis and Critical Control Point (HACCP); procedures for the safe and sanitary processing and importing of juice; final rule. Federal Register. 2001;66(13):6138–6202. Codified at 21 CFR Part 120; the 5-log requirement is at 21 CFR 120.24(a).
12. Regulation (EC) No 852/2004 of the European Parliament and of the Council of 29 April 2004 on the hygiene of foodstuffs. Official Journal of the European Union, L 139, 30.4.2004, p. 1.
13. Commission Regulation (EC) No 2073/2005 of 15 November 2005 on microbiological criteria for foodstuffs. Official Journal of the European Union, L 338, 22.12.2005, p. 1. Criteria for unpasteurised fruit and vegetable juices at Annex I, Chapters 1 and 2.5; definitions amended by Commission Regulation (EU) 2019/229.
14. EFSA Panel on Biological Hazards (BIOHAZ); Koutsoumanis K, Alvarez-Ordóñez A, Bolton D, et al. The efficacy and safety of high-pressure processing of food. EFSA Journal. 2022;20(3):e07128. doi:10.2903/j.efsa.2022.7128
15. Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children’s development and health. Official Journal of the European Union, L 136, 25.5.2012.

This article is educational. It is not medical advice, and nothing here is intended to diagnose, treat or prevent any condition. If you are pregnant, breastfeeding, taking prescribed medication — anticoagulants in particular — or managing a diagnosed condition, speak to your doctor or pharmacist before making changes.