Question: what is the most interesting part of finding an environmentally friendly washing powder and why

Jessica Liley answered on 21 Nov 2013:

The most interesting part (and the most fun) is actually making it!

For a start, I get to travel to do the work so it’s nice to live somewhere different for a while 🙂

To make the detergent (which is the part in washing powder that gets things really foamy), I have to first grow up the bacteria that makes it. It grows in water, inside lots of big flasks. This normally takes a few weeks, and I have to keep checking that the bacteria are still growing happily. They produce a bright colourful pigment while they grow, so the solutions are quite pretty!

After 2-3 weeks, I take the bacteria solution and use a centrifuge to remove all the bacteria cells – this is a big machine which spins round 1000 times per minute (that’s nearly 20 times every second!) to make all the cells collect at the bottom under the force of gravity.

Then I need to shake the solution left over with different organic solvents which don’t mix with water. The detergent will move from the water layer to the organic layer. And finally when you dry off all the solvent, you’re left with a brown sticky substance which is the detergent!