Wednesday, 20 May 2009

Worms, tea bags and tissues

I mostly concentrate on the “big” international issues of sustainability but here’s a few words on composting and wormeries.

Just about every site on worm composting tells you to compost your teabags – ditto if you just have a normal compost heap.  Despite a lot of Googling I have not yet found anyone else who has spotted the following aspect.

After a few years of composting my kitchen waste in my wormery, I spotted that there was a layer of “net” forming in the worm compost and it proved to be “skeletons” of tea bags. I phoned up a couple of tea bag makers and discovered that, although mostly paper fibres, the manufacturers include a small percentage of polyester fibres in the bag material. This is to enable the bag to be heat sealed when they press the two halves together.

Although the worms do a good job of eating the tea leaves and the paper part of the bag , they obviously leave the polyester alone and it builds up to form an indigestible, non-compostable layer. The same thing happens in a conventional compost heap but the scrap of polyester is almost unnoticeable. Most people who want to make organic compost would not like this plastic residue in it so the solution is to rip your tea bags and pour the contents into your worm caddy or big compost heap and (sadly) put the actual bag into the rubbish. It’s easiest to do this when they have cooled down or dried out (if you have the patience).

I think readers should spread this news or we are going to have veggie patches full of increasing amounts of polyester!

I recently discovered that most facial tissues these days have temporary “wet strength” additives. I have a done a little research on this and the additive appears to be a polymer resin that does break down after it has done its job. So far, I can’t find out definitively if the break-down products of the polymer are helpful, bad or indifferent to making good compost so I’ll carry on researching until I find out (when I get some time). I’ll report back here then. I note that “Bounty” kitchen roll (recently renamed Plenty) is now supposed to stay strong so I suspect they have used a permanent wet strength additive that will not break down.

5 comments:

st-ouennais said...

It's a salutory lesson - a little adulteration gets in the way of really good things.

Alea said...

Thanks for the information! I will make sure to pour the tea out of the tea bag before i compost it.

We use hankerchiefs and cloths kitchen towels, but I will pass the word on kleenex and papertowels.

Simon Sherlock said...

I have noticed said teabag "ghosts" in my heap but never in the wormery. There is also an increasing number of manufacturers who want to change to nylon teabags but I'm rather hoping that the obvious anger this has caused makes them change their minds!

JoeGreenHome said...

I have just got off the phone with Equal Exchange. Their "pyramid" style tea bags are PLA (corn plastic), allegedly biodegradeable, but not home-compostable. There's something inherently yucky about steeping plastic in my hot cup of tea. Let's all call our favorite tea companies and stage a "teabagger protest"...Joe Nolan, owner, Home Green Home

Soshanna said...

Thanks for sharing, I am an avid composted and have had two wormeries for 3 years now. I occasionally notice teabag ghosts but not from my rooibs tea from home, will be drinking that only now and emptying the rest :-)