The Danish are turning urine into beer – should Ireland also be taking the piss?

An article in the Irish times last week looked at how Copenhagen microbrewer Nørrebro Bryghus collected 54,000 litres of urine from festival-goers in order to make a beer caller “Pisner”. The urine was transformed into fertiliser and yielded it into 11 tonnes of malting barley. After harvesting and brewing the malting barley, the beer will hit the market in June this year.

While this novel way of making beer is helping a microbrewery make a splash internationally, it is also preventing the harmful nutrients found in human urine, from making it’s way into waterways around the festival, harming the environment. In Ireland, Herr Ltd is also investigating how you can use urine and still come out smelling of roses!

At the ReDiscovery Centre in Ballymun, County Dublin, human urine is being used as a fertiliser for the growing of garden flowers and other green plants . This pioneering system is part of an ecological and hygienic method to separate, recover and eventually to recycle nutrients, such as phosphorus, from urine. Phosphorus is a powerful fertiliser for plants but is also responsible for toxic algal blooms in Irish lakes every summer. Herr Ltd are interested in exploring if in the future, gardens in our cities will be using plants and flowers to remove the nitrogen and phosphorus from human urine, helping protect our lakes from algal blooms.

According to Swedish scientific research – human urine from individual homes contributes approximately 70% of the nitrogen and about 47% of the phosphorus found in waste water discharges. It is a sobering thought then, that by separating human urine from the other waste water in domestic houses, we can reduce by over 50% of the nutrient pollution that contributes to these unwanted algal blooms in our lakes.

The separation of urine is presently being practiced in places in Sweden as a method to protect the Baltic Sea from algal blooms in summer. Ireland should consider doing likewise to protect our inland water bodies and water supply sources.

There is often a lot of controversy and opposition against the use of sewage sludge on agricultural land; because of the concentration of toxic metals in the sewage solids from large towns and cities. However, the Herr Ltd system tackles this issue by separating the toilet solids from the urine, which is safe to recycle. At the ReDiscovery Centre, toilet solids separation and composting has also been installed. This additional urine treatment system is a major element in the Herr Ltd waste water pollution-avoidance system.

It must also be remembered that in a similar way to oil, phosphorus is also a finite resource. The coming era of Peak Oil and the coming end of cheap Phosphorus will cause fertilizer prices to rise eventually to unaffordable levels. These will in turn cause future food scarcity and economic hardship for many around the world in the future.

The Herr system uses the urine to grow green plants which are then periodically harvested. The cut leaves can be placed around the garden where additional fertility is required. In this way nitrogen and phosphorus nutrients can be recycled. Human urine contains none of the harmful toxic metals that are present in municipal sewage sludge.

Up until now there has been no urban friendly (system which doesn’t need lots of space) eco technology that can prevent the nitrogen and phosphorus, that still remains after conventional domestic electro-mechanical treatment systems, from polluting our aquifers, rivers and lakes. The problem is that if we continue to be wasteful of nitrogen and phosphorus then algal blooms will continue to grow in summer on Irish lakes that are polluted with these nutrients.

If early signs at the ReDiscovery Centre are anything to go by, the urban gardens of the future will be using plants and flowers to not only prevent urine polluting of waterways but will be using this super fertiliser to grow flowers and food leading to a more sustainable future for all.