How a beer gets made from toilet water

It's actually the last bottle of its kind. It's called Reuse Brew and it was made from recycled water. We went to the wastewater treatment plant in Berlin to see the high-tech water cleansing project behind the beer in action.

The Wastewater plant in Berlin, Germany is a huge facility that processes the water for 1.3 million people. 

Most of the plant is dedicated to simple techniques for filtering the particulates out of wastewater. 

The plant smelled worse than I could have imagined. 

Most of the methods used to clean water have been practiced for years. 

We were told to make sure we didn't fall in. The wastewater was dense enough that we would have sunk. 

These large vats do most of the work. Pipes introduce bacteria and oxygen to make the particulates easier to filter. 

The facility reuses the bacteria by skimming the sediment at the top and bottom of the tank near the end of the filtering process. 

This first step gets the water 97 percent clean. That's good enough to reintroduce it to certain groundwater sources and to use it for agriculture. 

Berlin's soil acts as a natural filter for the water reintroduced into lakes and streams. This smaller circular vat does roughly the same process as the bigger tanks. 

We all had trouble coping during the tour. 

To make the wastewater drinkable, the treatment plant partnered with a water technology firm called Xylem. Xylem makes this Ozone filter that actually produces ozone and introduces it into a controlled stream of wastewater.

The ozone breaks down chemical waste, then the plant introduces the water to UV light to help kill chemicals. 

After the ozone and UV light, Xylem uses natural carbon filters like soil. 

Here's the smaller system of filters used to test the process. 

Each filter used a slightly different order and amount of soils to see what would work the best. 

They scaled up the filters to these large containers. 

Even these filters only process a small percentage of the plant's water. It's still a pilot program. 

Xylem is continually measuring results and experimenting to make the process more effective and efficient. 

The beer was brewed as a one-time project to show that the tech works well enough for human consumption.

The beer was a hit. Xylem brought it to a water tech conference and this was the last bottle left. 

After some hesitation, I tried the beer. It actually tasted great.