Composting cooked food waste

I got my first composting-related injury yesterday by bashing my knuckle against the wall while aerating my compost. If you can avoid it, please site your compost bin some distance away from brick walls. Unfortunately, I do not have that luxury, but I am now all the more tempted to purchase an aerator rather than making do with an old mop handle. Aerators, as the name suggests, help move the compost around to let the air circulate better. They do not ‘turn’ your compost as such, but do so more than prodding the heap with a long stick! They cost around £10 – £20 and are surprisingly effortless to use.

In my last blog post I looked at the conventional methods of composting. These are all well and good but when I first started composting they just didn’t appeal – as a standalone method, at least – because I couldn’t compost everything that could, technically (because it was once a living thing), be composted. My main concern was, and is, food waste. Obviously, I minimise this as much as possible but with two young children I cannot prevent it entirely and it does not then make sense to throw these no longer edible leftovers into the general waste when I am composting the rest of my kitchen waste. I cannot throw it into the compost bin because 1) it could attract pests and therefore spread disease, and 2) cooked food does not compost as quickly and effectively.

Fortunately, various methods for composting cooked food waste exist.

1) Wormeries

Worm composting – or vermiculture – creates a dark, crumbly, nutrient-rich compost as well as a liquid that can be used as plant feed (diluted 1:10). Worms – brandling/tiger worms, or night crawlers – feed on kitchen waste from one end of their body and produce casts – basically, worm manure – from the other end. These casts are the worm compost.

Wormeries come in two forms – tiered, stacking bins or a singular, non-stacking bin. The obvious advantage is with the tiered bins as this makes it far easier to harvest the worm compost because you do not have to disturb the worms. Wormeries are possibly the most varied of all bins, and can either be purchased (£40-70) or made yourself using an abundance of materials. They are also an ideal solution for anyone short on space – for example, someone who lives in a flat without a garden can produce compost inside and use this on any pot plants they may have. Wormeries are actually well-suited to indoor composting because worms prefer the warmth. And besides, it’s rather like having pets.

So, what can you put into a wormery?

The usual: veg and fruit peelings (but avoid citrus peel and onion peelings as the worms do not like it), crushed egg shells, tea leaves, coffee grounds, kitchen paper, shredded paper, egg boxes, toilet rolls, cut flowers.

The unusual: leftover cooked potatoes and other cooked vegetables, leftover rice and pasta.

Avoid: citrus fruit and onion peelings, meat, fish and dairy products, dog/cat faeces, diseased plant material, non-biodegradable materials.

Like conventional composting, remember to make sure there is a mix of greens and browns so that the bin doesn’t get too hot or wet (you don’t want to kill your worms!)

I would love to have a wormery and sometimes I think I should have got one of these before getting my bokashi bins, but we get through a lot of citrus fruit in our house, and a wormery does not solve the ‘all food waste’ problem. It is a good solution, however, if you only want to make a small amount of compost.

Bokashi bins (£20-£60 + bran (about £20 for a year))

Bokashi isn’t actually composting because it is an anaerobic process of fermenting food waste so that it can be safely composted. It uses a special bran which contains effective micro-organisms. Raw and cooked meat and fish (including bones), dairy, bread, and all other forms of cooked food can be placed in the bin alongside vegetable peelings, coffee grounds and tissues. It has been bothering me as to why manufacturers do not advise putting tea bags in so I (finally) searched for an answer – it is because the effective micro-organisms that are an essential part of the bokashi process do not work properly if the waste is too wet. The solution is to ensure teabags have dried out before they go in.


The process:

Each time you put waste into the bin you have to sprinkle it with bokashi bran and squash it down to let out any air, then reseal the lid. There is a tap at the bottom where you drain off excess liquid (this can be diluted 1:100 and used as a weekly plant feed, or – it is this potent – for keeping your drains clear and fresh). It is best to have two bins because when one is full you need to leave it for 2-3 weeks to ferment, in which time you start filling the next.

On the face of it, bokashi bins are an ideal solution for anyone with minimal space who is interested in managing their kitchen waste, but the key problem is: you do not produce compost and so you still need somewhere to dispose of it. You can either add it to an active compost bin (with lots of browns!) or bury it in a trench. But you need the place to do this. I have read about universities (mainly in the USA) where they have communal compost bins, which students are able to add bokashi-treated waste to, but in the UK at least there are laws relating to community composting and what can then be done with the resultant compost, etc., so this might be more complicated to initiate. (A blog post for another day, perhaps.) Overall, I’m still in two minds about bokashi composting.

Trench composting5430765694_79edaafb69_z

A brief mention here as this is one way of disposing of bokashi-treated waste, but likewise useful for fruit and vegetable waste from kitchen and garden. In this method, you are burying your waste so that when it decomposes it adds nutrients to the soil. Trench composting is best done over the winter and early spring so you can then grow on that spot the following summer and reap the benefits!




hpp1Green cone (£85)

If I had a garden with a fruit tree of some description, I would have one of these. Green cones are basically food digesters. Because they are fully enclosed you can dispose of raw and cooked food waste, including meat, fish and dairy. You do not get any compost from the green cone, but if you site it by a fruit tree, for example, then this will benefit from the nutrients entering the soil.



Next post: the all-encompassing super-compost bins.




Using up leftovers isn’t just about not wasting food, it is about making the most of what you have. I know I am not alone in opening the cupboards/fridge/freezer and thinking I have nothing for dinner so I order a takeaway instead. Yes, it is rare for me to do this (takeaways are generally planned, or at least have to be flexible within my menu planning), but I admit that there are days when I am flummoxed and have no inspiration whatsoever.

Generally when we think of wasting food, and using up leftovers, perishable food is top of our concerns (which they should be), and we neglect the freezer and the store cupboard. The freezer is, of course, perfect for those occasions when you reach for the takeaway menu – just make sure you label everything, and even keep an inventory, unless you like surprises or playing guessing games through the frost (I’m the latter). The store cupboard is a whole other ball game, but one that is much more fun – mainly because it usually means baking.

It is important to keep a well-stocked store cupboard, not least because when zombies/the apocalypse/environmental disaster hit you want to be prepared, but particularly because these ingredients help tie your perishables together in what might otherwise have been just a plate of veg (I’ve been there). The problem with store cupboards, however, is that they do end up with a lot of forgotten ingredients – the things you bought for just one recipe, in my instance things like quinoa and pearled spelt, or things that just come in too big a packet (baking powder! I can do baking once a week and I still don’t use the whole packet before it becomes useless! I have solved the bicarbonate of soda (baking soda) and cornflour problem though as I use these in homemade deodorant, plus Doves Farm sells substantially smaller packets of cornflour than supermarket own and other brands).

Remember, non-perishable items usually have a best before date as opposed to a use by date. This refers to the quality of the product and not its safety. Baking powder, yeast and spices are good examples of products that are best before the date stated on the label. You will notice a difference in rise of cakes and breads if your baking powder and yeast have been open a long time. Likewise, the flavour of spices will be nowhere near as potent as when you first opened that packet and took a good whiff. Suitable storage will help improve the longevity of any food, be it perishable or non-perishable. And, at the end of the day, even if something does last indefinitely, it is always going to be better to just eat it!

The forgotten ingredient in these flapjacks was a solid block of 100% cocoa purchased at the Eden Project about 5 years ago.


The flapjack base:

85g light brown sugar

1tbsp golden syrup

85g coconut oil (I didn’t have enough butter so I thought I’d experiment with dairy-free flapjacks!)

75g oats

Heat the sugar, syrup and oil over a low heat until the sugar has dissolved (not all of the oil incorporated into the mix so it might be worth using left of it). Stir in most – but not all – of the mix into the oats so that it is clumping together nicely and bake at 180C for about 15 minutes.

The toffee:

Turn the heat up and let the mixture in the pan bubble away for a minute (there is a proper way of doing this but I just guessed – I also didn’t want to overdo it as I still wanted it to be a bit chewy and gooey). Pour onto greaseproof paper and leave to set.

The chocolate:

Icing sugar (about 5tbsp)

Water (as much as necessary to get desired consistency)

Solid cocoa (or you can use cocoa powder, sifted into the icing sugar, instead) – about 1tbsp

Whisk together icing sugar and water (sorry for no precise amounts, but I tend to make it up as I go a long as it always end up a sloppy mess if I follow a recipe). Melt the cocoa in the microwave and whisk this into the icing. Beat it until it is holding its shape.

The finished product:

When everything has cooled, layer the toffee on top of the flapjack (cutting if necessary), then spread the chocolate icing over the top.

Summer berry tea jelly

20160515_171550[1]I’m not a big dessert person. Give me chocolate or biscuits and I’ll ravage the lot, but when it comes to making desserts at home I’m not particularly adventurous and I don’t enjoy making them anywhere near as much as savoury dishes. My repertoire of desserts is crumble, bread and budding pudding and rice pudding, and this is usually only at weekends.

Last weekend, however, I was minus all the ingredients for all of the above. Raiding the cupboards I found a box of gelatine sachets that I had bought to make a jelly that was an epic failure (saved, somewhat, as a chewy orange sorbet). I thought I would try again, although I had nothing to flavour it with. Until I remembered I had a couple of teaspoons of a summer berry fruit tea left in the tea caddy and ta-da! I boiled the kettle, brewed the tea along with a tablespoon of sugar, and when it had cooled I made the jelly according to the packet’s instructions. And, yay! It set!

Personally, the flavour was very subtle and in need of more sugar, but the boys wolfed it down, and it is certainly something I will experiment with again – and a good way of using up all the random flavoured tea leaves/tea bags that I seem to collect! (Another good use for these is for macerating fruit, or making tea loaves.)

(I have since discovered I still had some beetroot brownies in the freezer, so that’s next Saturday sorted!)


Choosing a compost bin

Dalek, beehive, New Zealand, bokashi, wormery, green cone…

So many types of compost bin – a tricky decision or an obsessive addiction?

Choosing a bin is not that difficult as bins exist for a range of budgets, space, agility and needs. The difficult bit is perhaps deciding which one to get first. (I remember us all looking at a fellow trainee on the Master Composer course with bemusement when she told us she had nine compost bins but by the end of the course I think we all wished we had nine compost bins!)

The following bins are suitable for traditional home composting where you do not want to compost any cooked food waste, for example.

Dalek £10 – £30photo201_tcm44-194281
(and other plastic-moulded bins)
Cheap and cheerful and does the job. Often subsidised by the council but also available at the likes of Wilkos so it’s worth shopping around.  Just as effective as more expensive bins but the main downfall is access to the finished compost as the hatch at the bottom is small and awkward. It is easier to lift the bin off completely and put the top layer of unrotted material back in the bin leaving you a pile of compost (likewise for turning the compost). This however requires body strength and enough space to resite the bin. It is also not the most attractive bin but there are ways around that if money is an issue.



20160327_104902(Another cheap option is a compost bag. These do not seem very widespread and have mixed reviews, particularly in terms of durability, but I am currently trialling one as it met my current needs.)


Beehive £100 – £150

There is a price to pay for beauty although some models are similar to the dalek in terms of compost production and access to the finished compost. However, the compost is perhaps easier to turn and add raw materials to. Its main selling point is its attractiveness.


New Zealand Boxes £0 – £100

26675998015_afed3327fb_zThe main advantage with these is that you can leave one bin to decompose fully while you start adding raw materials to the next bin. These bins are wide making them easier to turn, and often have removable slats making it far easier to access the finished compost. If you are handy with wood and a toolkit then it is also easy to make your own (often at no cost if you get your hands on some old pallets). These bins are not good for anyone with limited space, but if you do have the space you are not limited to two – why not have one just for leaves to make leafmold, for example? Bins can be open or lidded depending on your circumstances.


A simple heap, old bins with the bottom cut off, straw bales, post and wire mesh, and wooden pallets are all good ways to start composting if you don’t want to buy a bin. There are plenty of instructions for these online and I also have a couple of ‘how to’ guides on these methods if you are interested.


My dad’s homemade bin

My next post will look at more unconventional composting methods but in the meantime go out and buy/make a bin and get composting!


At my first workshop.

Stuffed peppers

The ultimate simple supper for just about leftover everything (curry, chilli, bolognese, rice, pasta, potatoes, veg, cheese…). I’ve been cooking stuffed peppers quite often recently, partly because peppers make a regular appearance in my Wonky Veg boxes, but they are such an easy meal that can be made either on the day or in advance. I like to cut them in half (rather than fill the whole pepper) and sit them on a layer of tomato-based sauce. Then, I layer them with rice, finely chopped veg (usually mushrooms, onion and more pepper), refried beans (ideally homemade) and topped with cheese.

On this particular occasion I took a slightly different route.

20160510_204040[1]The base:

Half a tin of tomatoes, half an onion, clove of garlic and a sprinkle of oregano

Saute the onion and garlic until soft, add the tomatoes and oregano, and simmer until thickened. Season to taste and spread over the bottom of an ovenproof dish.

The filling:

Leftover curry sauce, leftover veg (courgette, pepper, onion), and leftover five bean salad.

Cut the peppers in half lengthways, scoop out the seeds, and place in the dish. Mix the filling and spoon into the peppers. Top with grated cheese (or mozzarella, breadcrumbs, whatever needs using).

Cover with foil and bake at about 200C for 40 mins. Uncover and cook for a further ten minutes until the cheese/breadcrumbs is golden.



What can be composted?

Strictly speaking, anything that once lived can be composted. This list includes anything from plants, food waste and dead animals to excrement and anything made from natural fibres. However, time, space, smell, disease and unwelcome pests are all factors to consider when determining what to compost at home (for non-domestic composting there is also legislation to abide by, particularly the animal by-products regulations which came about following the foot-and-mouth crisis).

19097872003_02d396ebbd_q (2)Compost needs warmth, air, water and raw materials. These raw materials fall into two groups: greens and browns. Greens are the wet stuff like vegetable peelings that are nitrogen-rich and quick to rot, and browns are the dry, carbon-rich things like toilet rolls and autumn leaves that are slower to rot but they help provide air pockets so the air can circulate through your compost. A balance between the two is essential for good compost. Although some schools of thought recommend ‘layering’ greens and browns, Garden Organic teach that this is not necessary so long as equal amounts of both are going into the bin, and suggest mixing drier, tougher ingredients with greens before adding them to the bin. This can be a challenge depending on your set-up – if you have a big garden and collect lots of garden waste then you might not need to worry. But, I find I have to pair my kitchen waste with things like toilet rolls, egg boxes, and other paper recyclables.


How can you tell if you’re getting the balance right?




‘Greens’ (nitrogen-rich ingredients)


  • Young weeds
  • Nettles (not roots)
  • Comfrey leaves – compost separately to make a comfrey solution, a natural plant food (a fellow Master Composter uses an old bokashi bin for this purpose)
  • Urine (ideally diluted 20:1)!
  • Uncooked fruit and vegetable peelings
  • Tea bags, leaves and coffee grounds (including coffee filters – make sure you choose biodegradable teabags and coffee filters)
  • Soft green prunings
  • Animal manure from herbivores (e.g. cows and horses)


‘Browns’ (carbon-rich ingredients)


  • Cardboard (e.g. cereal packets, toilet roll tubes and egg boxes)
  • Waste paper and junk mail, including shredded confidential waste (watch out for any plastic packaging)
  • Paper towels & bags
  • Bedding (hay, straw, shredded paper, wood shavings) from vegetarian pets (e.g. rabbits and guinea pigs)
  • Tough hedge clippings
  • Woody prunings
  • Old bedding plants
  • Straw
  • Egg shells (ideally crushed)
  • Natural fibres (e.g. wool and cotton)
  • Hair (avoid if it has been chemically treated with hair dye)



  • Grass cuttings – can be composted in moderation (mixed with dry material to create air pockets) but far better to compost separately, leave on the grass for the worms, or use as a mulch
  • Autumn leaves – can also be composted in moderation but far better to compost separately to make leaf mold26402462130_d3ab2aed04
  • Meat, fish, dairy products or cooked food (alternative methods are available – e.g. bokashi, green cone, trench)
  • Coal & coke ash
  • Cat litter and dog faeces (alternative methods are available, likewise composting toilets for human faeces)
  • Disposable nappies (even biodegradable nappies may take several years to fully decompose and unless a vegetarian diet is being followed then soiled nappies should be disposed of separately)
  • Do not compost anything that has been chemically treated – e.g. wood, carpets, dyed hair


Just because something is considered a caution does not mean it will not compost. As I stated at the beginning, anything that lived can theoretically be composted, but we can’t just pile it all on a compost heap without considering the environment around us. Some things, like large woody prunings and Christmas trees should be shredded before being added to a heap (it is also noteworthy that some Christmas trees are sprayed with fire retardant and you do not want those chemicals mixing in with your nutritious compost) but the quantity may still be too much for the domestic compost. Industrial composting (where council green waste collections end up) are therefore more suitable for large garden waste and things like poisonous plants and weeds which need higher heats to ensure they will not be harmful to the soil and plants. Food waste has the risk of attracting pests, and spreading disease. Likewise, the excrement of non-vegetarian animals. However, there are ways of composting these things in a domestic environment. My next post will look at conventional compost bins. Following that I will explore the more non-conventional options.


The above photo was taken on my training weekend (I’m the second one in with glasses). We had to use some of the resources available to us to set up a stall to show people about composting. I am running my first composting workshop on Saturday. If anyone lives locally (Loughborough, UK), then please check out the details here and book a place!