Composting · Food Garden · Homesteading · Observations · Soil care

Utilisation of Kitchen Scraps

Soil care fertile arable agriculture kitchen scraps composting ben_kerckx


Due to the technological and financial advantages of our modern age a lot of food simply gets wasted. You would think that with the development of all our superior food production and storage capabilities food will not go to waste so easily. The average person today is more wealthy that many medieval kings, yet ironically if you have food, clothes and a house you have more than 80% of the people globally. In that respect it is quite sad and shocking when you start to notice all the places where food is lost and I am not only referring to rotten or food not fit for human consumption. Large fresh stock supermarkets and restaurants are big culprits when it comes to throwing away food that is still edible, but has passed the sell-by date. We as consumers are the worst! Many people don’t want to eat any food that is not attractive (whether this is by smell or appearance) and don’t want to eat gnarly looking apples (even though they are more nutritious and tasty) that have been produced with minimal environmental impact… Most people are very happy eating tasteless commercial produce, which is likely forgotten and thrown out with the trash without any further thought – because they have the thought that can just go to the grocer to get a new one.


Recently a lot of people have been moving towards more ethical and responsible use of consumables, including food (see the Inglorious Fruit Initiative and French Food Waste Donations – seems like the French set an example for all!). In developing countries it is estimated that  nearly 100 kg of food is lost per year per person (just to put that into perspective – we had 120 kg worth of produce from the summer and winter garden 2013/2014 collectively for 1 year – that is a lot of food! Likely enough to feed 1-2 people for a year!). Food is biodegradable, so composting your food waste already goes a long way towards trying to make back what has been lost, especially if you can distribute that to your vegetable garden to make the food back in a small way. Yet certain foods cannot be composted, such as starch and meats. I am going to provide some suggestions and a table on how to re-allocate food waste, either to a third party that can eat food unsuitable for human consumption, or it can go towards the next season’s crops with various decomposing/composting methods.


Kitchen scrap composting table
The table has been scored according to preference regarding my personal observations of which foods work well for compost or are particularly appreciated by other systems. The compost heap refers to an outdoors heap made in or on the ground. A compost bin refers to a closed system, such as those specialised composters or dustbins with drainage. Both the compost heap and bin are generalised systems that can take just about anything expect large quantities of meat, starch or dairy (if some slip in as part of a mainly-vegetarian dish then it’s OK). As you move away from the composting system they become more specialised. Citrus peels and maize cobs, after they have been stripped of any remaining flesh by the birds and chickens, respectively are great additions to the compost systems. The peels and cobs add fibrous water-retentive material to the compost heap. For more information on the composting system, see my Composting Page.
Kitchen waste bucket
Kitchen scraps collected in a bucket for the compost heap
Earthworms have additional critters that live with them in their systems, which you either inherit with the purchase of the worms from the previous owner or they simply introduce themselves into the system. I have tiny crustaceans, springtails and black beetles in my worm farm. None of them threaten the earthworms and seem to co-exist quite happily, decomposing material the earthworms find tough or not-so tasty. Earthworms love rotten peppers (sweet bells), any flesh remaining on watermelon rinds and banana peels! They will dangle from the peels when lifted from the farm LOL! Tea bags and spent coffee are another sure favourite as the material is already partly broken down and make for easy worm digestion. If you have to prune some herbs and have too much leaves to deal with you can toss a good thick layer of this onto the worm farm, the worms will make quick work of it. The worms will eat tougher stuff like potato peels and such, but do prefer more squishy things.
However, the crustaceans, mites and beetles will consume very fibrous materials – they also eat any dairy (some crumbs of feta from a once edible salad won’t do harm to the system). Generally dairy, starch and meat are not added to the wormery, since they’re strictly vegetarian! I would also suggest limiting citrus, onion or vegetables from the cabbage family. These alter the pH of the wormery to be more acidic (which the worms tolerate, but it attracts pot worms to the system who compete with the earthworms for food), also too much cabbage make for a smelly wormery. Eggshells are good to add to the wormery as it balances/buffers the pH as well as providing additional hiding places for the worms (they like to chill-out a bit in the mostly whole shells). Thus, earthworms will eat any rotten/mouldy vegetables or fruits as well as fresh surplus from the herb garden. Another note, I have noticed that earthworms don’t like lettuce; they’ll eat spinach or pak choy, but won’t eat the lettuce (which makes me wonder why do we eat it?). For more information on wormeries, check out my Wormery Page.
Soil care fertile arable agriculture wormery vermicomposting bluebudgie
Chickens love tomatoes, so any tomato waste (such as cut off tops) that is not mouldy or rotten can go to the chickens. The appreciate other fruits as well (especially fruit peels with some flesh inside or eaten maize cobs – they’ll pick it clean), but most of this will depend on their personal preferences, for example we had one chicken that didn’t like tomatoes all (I mean what respectable chicken does not enjoy tomatoes), but loved bananas (she’ll even clean out the peels!). Depending on the breed, there will also be different preferences, for instance some are bred to forage for most of their food and thus will be enjoy leaf-based scraps. Most chickens like plants from the cabbage family, such as kale, pak choy and also enjoy spinach or lettuce. I usually leave the pak choy to flower for the bees to have some flowers late winter, but pluck out those setting seed – I saw that the chickens will deftly peck open the pods and eat the seeds inside. For some reason our new chickens have decided that they like basil! They have completely hen-pecked the basil in the ornamental garden and when I chuck some prunings on the ground from the one in the vegetable garden they ravage it in a few minutes flat. I don’t think that this is standard practise for chickens to eat herbs, but if they do at least it’ll help with their digestive wellbeing LOL! All starch food waste (not too salty) can be given to the chickens, even if it has little bits of mince or cheese along with it (such as in some pasta dishes).
Chickens are crazy about dairy, just don’t feed too much as it is high in fat, but it can be a great treat (especially in winter) if you give them some milk soak bread! I would suggest not feeding them cooked chicken or eggs – there is something terribly wrong with that in my opinion. While on the subject of eggs, eggshells can be given to chickens as part of their calcium and grit intake. Some people clean, dry out the eggs in the oven and mash them up before giving them to the chickens, whereas ours just help themselves to the eggshells in the compost heap. I know that some folk say that you *may* promote cannibalism and egg eating if you do this, but I have found no evidence of this. The only time I have seen chickens eat their own eggs is when they had a big scare and laid a shell-less egg afterwards. They peck open the membrane and eat the egg, which to me does make sense as they know that the egg is unviable and it is unwise to waste energy, so the shell-less egg is promptly consumed and the energy returned to the chicken’s body. You can feed the chickens meat, but I will keep it in reasonable amounts since meat also contains a lot of fat and salt. If your chickens have access to the compost heap, they will also help themselves to whatever they like in there as well – I am usually of the principle that chickens know what they can’t and cannot eat. For more information on chicken keeping check out my other posts in the series: Food and Housing.
Farm Rooster Hen Chicken Forage Backyard Free range
All right! For those without chickens I suggest setting out a lot of you fruit, starch and even dairy food waste for the birds (even if it is rotten or mouldy). The fruit lovers will swoop down on any apple or pear cores and will clean out the peels of bananas and citrus (such as grapefruit with some flesh still inside). In winter when food is scarce this becomes a big help to a lot of birds, even the fruitivores will help themselves to rice, cheese and vegetable scraps. You can even plop down a spoonful of sour yogurt in a bowl for them (good for the crop) – chickens also enjoy yogurt! We have our fruits skewered on wire that has been stuck into a piece of polystyrene and fastened to the tree branch. All the other goodies are in a large (broken) pot saucer on the wall (with a brick inside to prevent the wind from blowing it off). I would suggest putting out food for the birds in the trees or on walls close to trees as they want to feel safe when eating. Feeding the birds this way will also give you an opportunity for some birdwatching! Generally speaking what the chickens can eat, the birds can eat.
Apple cores for birds feeder garden
A collection of some apple cores, oats that fell on the floor and some other unidentifiable things for the birds…
Mushroom compost is mainly made from hay, but if you already are growing mushies, you can add tea bags and spent coffee to this for some added nutrients. I tried to grow mushrooms from spent coffee and pine saw (hamster fluff) – after collecting and drying millions of spent coffee and tea bags from the household… the mushrooms grew really well, I had nice thick mycelium throughout the medium. The biggest problem was fruiting, as our climate is not really suited to mushrooms and I tried all kinds of different things to get the mushies to fruit properly. They would make tiny little fruiting bodies and some would simply shrivel! Very disappointing considering how much I like mushrooms (both to eat and as a research topic!). Anyways, if you like to grow you own mushrooms with spent coffee at no extra cost you can give this system a go! Mayhap you would be more successful than me! Let me know! For more information on growing mushrooms as home, see the Mushroom Guru website.
Mushroom compost fruiting bodies
Mushroom fruiting bodies from my experiments – the biggest they got were about 5 cm.
Next up, Bokashi! Now from this point forward I cannot supply my own personal observations as I have not done Bokashi, neither have I kept mealworms (the main reason being that it is not a self-sustaining systems and you need to continuously buy new substrate…). Bokashi contains a mixture of anaerobic fermenters, which includes bacteria and fungi. Basically you are pickling the waste by a natural biological process, which occurs without the need of oxygen (anaerobic). Because of this you can ferment anything, vegetable and fruit matter as well as meat, bones, dairy and I assume starch as well. The main point is not to get the system too wet, because that when it becomes a smelly business! I imagine the fermentation process will also take some time and that it can only get through a certain amount of food (likely an average sized family will generate too much waste for the system to deal with in a short amount of time). After the fermenters have done their work, the contents is added to the compost heap or buried in the soil for further decomposition. I would venture that if you buy this system just to deal with your meat and dairy waste, it might be a bit more sustainable. If you would like more information on the Bokashi system, please see the Earth Probiotic Recycling website.
Bokashi Composting
Bokashi Composting
I was very interested in raising mealworms at one point as additional protein for the chickens, but the main substrate for mealworms is wheat bran or oats, which you have to constantly buy to sustain the colony. This system is basically a colony of beetles, which will go through their life cycles from egg throughout the larvae, grubs and beetles stages. You can feed them additional vegetable and fruit scraps from which they receive their water as well. As long as the substrate doesn’t become wet and the colony is kept at room temperature they will happily go about their lifecycle ensuring that you have an on-going food supply for the chickens. If you would like more information on how to keep mealworms (Tenebrio molitor) as chicken feed, see the following Post @ Backyard Chickens.
Mealworm larvae, Tenebrio molitor
Mealworm larvae, Tenebrio molitor
Do you have any additional suggestions for the use of kitchen scraps? Please share!

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