Part 5 of an experiment in home composting.

I started this experiment on 28 April 2019 to see whether The Guardian’s compostable bags do actually degrade in a home compost heap. I’ve added a few further items along the way, and am now checking up on everything for the final time this year.

I dug over the heap once more on Monday 28 October, eight weeks after the last check and 26 weeks after I started the experiment. Again, I removed all the material carefully with a spade and trowel, placing it as I went into a large bin.

The only possible sighting of the compostable cup which I had placed in the heap on 1 September was this small fragment.

However, it could be a small piece of cardboard from an egg box or similar. Either way, I think we can record this as something which has pretty well completely composted.

Further down I came across the Happy Pear compostable pouch which I placed in the heap on 4 August. It has still not decomposed much – if at all – as you can see from the picture below. I didn’t expect to find much progress on this, even after twelve weeks. The label says it is designed for industrial composting, so I’m not very optimistic that it will ever break down in a domestic situation. But we shall see.

I had to dig right down to the bottom of the heap to come across these very small fragments of the Greensax compostable bag placed in the heap on 28 April, distinguishable from the Guardian bag by the green printing. These are just a few centimetres in length. There was no sign of the original Guardian compostable bag.

These were at the bottom of the heap, so I concluded the experiment. Here is a report on all the items in the form of a table:

Date	Item	Completed decomposition time
28 April 2019	Compostable bag: source The Guardian	Approx 26 weeks
28 April 2019	Compostable bag: source Greensax	Small fragments at 26 weeks
7 July 2019	Compostable wrap: source NJB	Approx 8 weeks
4 August 2019	Granola pouch: source Happy Pear/TIPA	Not yet decomposed
1 September 2019	Compostable cup: source Down2Earth	Approx 8 weeks

I put all the part-composted material back, and have added a layer of fallen leaves and some more kitchen waste since. Now I am going to leave everything until next spring.

Part 1, 28 April 2019. 
Part 2, 7 July 2019.
Part 3, 4 August 2019.
Part 4, 1 September 2019.

Part 4 of an experiment in home composting.

I am conducting an experiment to see whether The Guardian’s compostable bags do actually degrade in a home compost heap.

I checked up on the heap again on Sunday 1 September, four weeks after the last check and eighteen weeks after I started the experiment. Again, I removed all the material carefully with a spade and trowel, placing it all into a large bin.

The first item I came across was the Happy Pear compostable pouch which I placed in the heap just four weeks before. It hadn’t decomposed much – if at all – as you can see from the picture below:

I didn’t expect to find much progress on this, certainly not after four weeks. The label says it is designed for industrial composting, so I’m not very optimistic that it will breakdown in a domestic situation. But we shall see.

Further down was the remnants of the compostable cup which I had added in July, at Stage 2 of the experiment. This has now further disintegrated further, so I’m pretty confident that this will vanish completely in due course.

Of the clear film bread wrapper left in the heap at the same time, I now found nothing. I can therefore record that this was composted completely within eight weeks.

Finally, I dug right down to the bottom of the heap to see what was left of the initial two compostable bags. These have been further reduced to a few very small scraps of compostable film:

It’s not now possible to tell from which of the two bags the scraps come, which is good news. It seems to me likely that there won’t be anything discernible by the time I next open up the heap, but we will see.

Finally I have decided to add another item to the heap: a compostable coffee cup made by Down2Earth Materials in Cork. (This firm may well have made the earlier cup which I placed into the heap in July, which you can see above. Unfortunately I didn’t keep a note of the manufacturer which is why I’m adding a new cup at this stage.)

Here’s the cup:

And here it is in the heap:

Once again, I’ve put all the part-composted material back, and topped the heap up with plenty of new kitchen vegetable scraps and garden waste. I will take another look sometime in late October.

Part 1, 28 April 2019. 
Part 2, 7 July 2019.
Part 3, 4 August 2019.

Part 3 of an experiment in home composting.

I am conducting an experiment to see whether The Guardian’s compostable bags do actually degrade in a home compost heap.

I checked up on the heap again on Sunday 4 August, four weeks after the last check and fourteen weeks after I started the experiment. Again, I removed the material carefully with a spade and trowel, placing it all into a large bin. A few inches down, I came across the material I had deposited four weeks ago. On the left you can see what it looked like then – a paper cup and a large transparent bag, which had been a bread wrapper.  I was pleasantly surprised to see that there is very little left of the transparent bag – in fact the printed label is the only distinguishable bit remaining. Here is what it looked like:

So hats off to NJB who say they make a compostable film. My experiment would seem to justify this claim. The compostable coffee cup has decomposed less, but it looks as though it is also on the way to breaking up completely.

I carried on removing material in order to reach the bottom of the heap, where the two original compostable bags were placed back in April. Here is what I found:

There is now very little left of either bag. The pieces shown above were the only traces of both, and I therefore have every hope that there will be nothing left to report next time round.

My latest addition to the experiment is a pouch which once contained Happy Pear granola, manufactured by the Israeli company TIPA. The packaging tells you to put this into ‘industrial composting’ (i.e. a brown bin) but as I only use our brown bin very rarely, I decided to see how well it goes in a home compost heap. Here is how I left it:

I’ve now returned all the compost to the heap. I will keep on adding more material on top and we will see what it all looks like again in a month or two.