Easy ice - an inexpensive cooling method for fishermen

Liquid ice and slurry ice have certain advantages over flake ice. The liquid “binary” ice surrounds shrimps or fish within just seconds, and the ice doesn’t have to be broken up, so a pickaxe and shovel are superfluous. With “Easy Ice”, the refrigeration engineering company Cooltech now offers a new soft, snow-like ice which provides fast intensive cooling. On-board production of Easy Ice is inexpensive and the machine requires only little space.

With their new ’Easy Ice’, refrigeration engineer Cooltech now offers a soft, snow-like ice which enables fast, intensive cooling. Production on board is inexpensive and requires only little space.

The use of flake ice on board fishing vessels has a number of disadvantages. For a start, the ice has to be taken on board and paid for already in the harbour. Conventional flake ice clumps together within just one to two days so that the fisherman has to break it apart with a pickaxe. Ernst Jahn, co-partner at Cooltech, sees a further danger here: ice burns: “When ice flakes at a temperature of about -6 to -10°C lie on the surface of the fish or shrimps the cell fluid can freeze. This cooling in one spot leads to freezer burns.” As an alternative, Cooltech from Satrup in Schleswig-Holstein, northern Germany, offers binary ice, also known as slurry ice or flow ice. One binary ice variant is pumpable. The ice surrounds the fish or shrimps completely so that the cooling process only takes seconds. Due to the storage space and pumps which binary ice machines require, however, they demand greater investments. With the new Easy Ice technology Cooltech has now presented an ice machine which does not need this technical periphery, making it less expensive than binary ice production. The machine also takes up less space on board.


Quick cooling rate without the risk of freezer burns

Easy Ice technology produces a snow-like ice with a soft consistency. With a salt content of three per cent Easy Ice has a temperature of -2.5°C. Water content is just 30 to 40 per cent making this ice comparatively dry and not pumpable. “The water between the ice crystals is in the form of capillary water and not as a flowing liquid”, explains Ernst Jahn. Because the microscopically small ice crystals (their diameter is less than 0.5 mm) have a fine structure and are not angular but round this ice does not stick together. The Easy Ice surrounds the fish or shrimps completely and thus has a better cooling rate than flake ice without any risk of freezer burns. The ice can easily be distributed over the fish boxes using a shovel.

'Easy Ice' is a snow-like ice which with a water content of 30 to 40 per cent is comparatively dry. Due to its fine structure it wraps itself around the fish or shrimps and has a better cooling rate than flake ice.


Compact, plug-in device

Because Easy Ice technology – in contrast to classic binary ice – does without an ice storage bin the machine is a small, compact, plug-in system which can also be used on board smaller fish and shrimp cutters. The water used for ice production is pumped into the ice generator from the sea. The required salinity is low at as little as 0.8 per cent which also enables its use in the western Baltic, for example, which is considerably less salty than the North Sea – salinity sometimes falls below 0.8 per cent. Jahn: “If the salt content is even lower there is the possibility of mixing to reach the minimum limit of 0.8 per cent.”


140 ice machines for Ecuador

The Easy Ice method is Cooltech’s latest development and is the result of 25 years’ experience in liquid ice technology. Since the company’s reestablishment in 2008 by Ernst Jahn and his commercial partner Detlef Hansen nearly two hundred ice machines with capacities of between 0.5 and 3.5 t have been sold to buyers worldwide. The machines’ sizes differ mainly in the height of the ice machine, the refrigerant evaporator, which is perceivable from the outside as a pipe. In 2011 Cooltech was very busy working on a big contract from a foreign customer who had ordered about 140 ice machines for use in Central America in Ecuador. Given the modest dimensions of the production hall the project had been a logistical challenge, said Production Manager Kurt Ivers: “To adapt to construction progress in Ecuador we had four delivery phases.” In Ecuador the air-cooled ice machines are to be used at on-shore shrimp farming facilities.

Cooltech - Company Fact File

Cooltech GmbH

Raiffeisenstraße 8

D-24986 Satrup

Tel.: +49 (0)46 33 - 96 85 15

Fax: +49 (0)46 33 - 96 85 17

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.


Business: Production of ice machines

Owners: Detlef Hansen, Ernst Jahn

Manager: Detlef Hansen

Technical Manager: Ernst Jahn

Employees: 5

Sales: 500,000 EUR

Founded: 2008

Product and space cooling for fish cutters

Binary ice from a Cooltech machine is used on board a South African hake trawler, and along the German and Dutch coast Cooltech has so far fitted three cutters with water cooled binary ice machines. In addition to Hallig Hooge’s only fish cutter and the Dutch 24-metre trawler “Jente” from Den Helder, the “GRE 37” from Greetsiel in East Freesia was equipped with an ice machine not only for cooling the shrimps after cooking but also for cooling the ambient air within the holds – both of these applications with liquid ice. Here the skipper could be sure of Cooltech’s competence in the field of space cooling which the Satrup company has also installed in the state parliament of North Rhine-Westphalia in Düsseldorf, in the new finger dock at Zurich airport, or in the Schleswig-Holstein state representative office in Berlin. This cooling method is also used in the production of sous-vide or cook & chill ready meals to cool the food as quickly as possible to below +8°C to prevent germ formation. Binary ice is also used for immersion cooling of fish. Ernst Jahn points out that it would also be conceivable to use binary ice and Easy Ice for keeping fish counters and display units cool. bm