Consumer group reviews in-store 'squeeze-your-own' juice: Clean, safe, full of vitamins and value for money

In a review of orange juice across the country's major supermarkets, the organisation tested the vitamin C content in each the moment it was extracted, a few hours later, then again at intervals of 24, 48 and 72 hours.

After this time, it is generally not suitable for drinking anyway, but the OCU says the levels of vitamin C remained the same at every test.

More and more Spanish supermarkets are offering a 'squeeze-your-own' service, where locally- and nationally-produced fresh oranges are piled into a giant machine, customers take an empty bottle, normally available in different sizes, and pump the juice into it themselves.

It is an ideal option for those who do not have juicers at home, and is more popular than the varieties sold by the carton – in fact, an increasing number of Spanish residents are tending to drink fresh juice rather than pre-packaged.

Some concerns have been raised among the public about the amount of additional single-use plastic this relatively new system generates, since as yet, no supermarket has a 'return' service for empty bottles, and reusing these after rinsing them out is strongly discouraged by stores – even though it is technically possible as the barcode reading applies to the product, not to individual bottles.

Customers who use the 'squeeze-your-own' machines are urged to reuse bottles for other purposes where they can, and afterwards, deposit them in the 'yellow bin', where plastic, cartons, tins and cans are recycled.

The OCU studied 24 samples in three different branches of each of the eight supermarkets it reviewed – Mercadona, Carrefour, Alcampo, Hípercor, Lidl, Aldi, Día, and Ahorramás.

Its first study addressed what turned out to be unfounded concerns among some consumers – whether the 'squeeze-your-own' machines were hygienic.

The organisation says the hygiene quality of juices depends upon how often the machines are cleaned, but stressed it did not find any risk in any of the juices or squeezers and considers the product to be very safe.

Although the OCU recommends freshly-squeezed juices are consumed within 24 hours and kept in the fridge during this time, it all depends upon how clean the machines are – and when the juice is pressed from a supermarket machine in store, it is perfectly safe to drink within 48 hours, even though anecdotal evidence points to its being fresh enough to do so for longer.

All supermarkets reviewed cleaned their machines thoroughly at least once a day, normally just before closing time – in fact, those who want to add a bottle of hand-pressed juice to their shopping basket should normally aim to get there at least an hour before their local branch shuts to be sure the machine was still in use.

The OCU reviewed prices, but did not find any difference in quality between stores – in fact, the oranges used are practically all grown in the Comunidad Valenciana in the east of Spain, one of Europe's largest orange-producing areas and one which supplies most of the supermarkets in the UK.

The cheapest half-litre bottle is from Alcampo, at €1.75, followed by Carrefour, Día, and Lidl, at €1.79.

Mercadona, Aldi, Ahorramás and Hípercor were the most expensive for a half-litre bottle, at €2.25.

But it works out cheaper to buy a litre instead in terms of economies of scale – these range from €2.89 to €2.99, lower in price during peak orange season, from about November to February, and higher in price when these are more scarce.

Although considerably more than a litre carton of orange juice from concentrate, the in-store 'squeeze-your-own' option is still good value for money – the machines filter out the 'bits', meaning for every 100ml of juice, a whole large orange is used, and buying the fruit to squeeze at home works out about the same price per orange as hand-pressing them in a supermarket.

Photograph: Mercadona