Experts for sustainable aquaculture and fresh vegetables from Vienna
blün – this the combination of blue and green (“blau” & “grün”), of fish and vegetables. These are also the colours of sustainability for the founders of the Viennese start-up blün. Behind this business, which is devoted to aquaponics, an innovative recirculation system, are four young farmers with a vision.
“We are completely convinced that quality, in conjunction with the protection of our oceans and the climate, as well as with consideration for our grandchildren, is the key for the future.”
This is the creed that the four founders of blün, Gregor Hoffmann with his friends Michael Berlin, Bernhard Zehetbauer, and Stefan Bauer, have committed themselves to.
Since 2016, they have been farming fish and vegetables at the edge of Vienna. And because they love good food just as much as innovation, they work with a state-of-the-art farming method, aquaponics. “‘Aqua... what?’ – I get this question a lot when I talk about our business,” laughs Gregor Hoffmann. “It is actually an ancient system of recirculation that farmers have been using for centuries, when they utilise the manure from their animals to make their fields more fertile. We do the same when we use the water from our fish as fertiliser for our vegetables.”
The “side effects” of aquaponics techonology and philosophy are appreciated by the restaurateurs in the Austrian capital as well. blün’s fish as well as vegetables can be found on Thomas Hahn’s menu, owner of one of the city’s top restaurants, Labstelle in Vienna’s first district: “The tomatoes, the wels catfish, and the perch absolutely won me over with their quality and remarkable taste.”
A conversation with Gregor Hoffmann
We are four fathers who want to use our abilities to make a contribution to making the world better for our children and grandchildren.

Aquaponics: a promising model for the future
When fish farming and vegetable cultivation are joined together in a closed circulation loop, this is called aquaponics. It is a sustainable, innovative technology in which no water is lost. Vienna’s piped-in mountain spring water, in which the fish swim, is turned into liquid nutrients for the plants in the greenhouse: tomatoes, cucumbers, courgettes, and aubergines.
The water is permeated with natural fish waste that supports the vegetables in their growth and contains neither heavy metals nor environmental toxins, as the fish – wels catfish and perch – are raised indoors and are thus also free of these harmful substances. In this closed-circuit system, nothing is lost, and everything is utilised.
Labstelle Vienna. “Food with no frills” is how this restaurant in Vienna’s city centre describes its cuisine. Essential for its culinary creations are high-quality regional and seasonal ingredients. Labstelle is one of many high-end restaurants in which fish and vegetables from blün are popular selections.

Where you can find blün products in Vienna
Vienna: One of the world’s greenest cities
Vienna has been voted the world’s most liveable city multiple times. There are countless reasons for this – one of them is that over half the city is covered with green spaces. Wherever you happen to be in Vienna, the nearest park is never far away. Expansive parks and nature conservation areas, the Vienna Woods, vineyards, and the Danube area are a pure delight for nature lovers.
It is no wonder that 456 species of bees make their home in Vienna as well – more than in any other European city. Another thing that’s good to know: the Viennese drinking water right from the tap and from drinking fountains in the city is pure spring water from the Alps – and one can taste it.
10 tips for discovering green Vienna
Dining in green Vienna
The harvest of art
The famous paining 'Summer' by Arcimboldos from his 'Four-Elements' series can be admired in the Kunsthistorischen Museum.