We’ve had an email from Jennifer asking:

I was on the verge of buying a soda siphon to make my own sparkling water at home – surely much more ecologically sound than buying bottled sparkling water, right? But my husband raised a concern about the used CO2 cartridges? Are they recyclable?

A not-so-quick Google around suggests that they’re metal (typically steel) so can be recycled with normal metal recycling. Anyone know for sure?

When we posted about water filter cartridges three years ago (cor! that’s ages!), we had a number of people making reuse suggestions – how to clean them to get more life out of the filters – are there any tricks like that for soda syphon cartridges?

Even if they couldn’t be reused or recycled though, it still might be worth considering the syphon route because of the amount of energy wasted shipping heavy bottles of water around the place.

Any other suggestions?