Conker Soap – Eco-friendly Laundry DetergentConker Soap – Eco-friendly Laundry Detergent

In four simple steps, we will show you how to produce, use and dispose of your conker soap granules.

Conkers, as well as being great for the traditional game of conkers, contain saponin, the chemical bit that makes soaps work.

Conkers can therefore be used as a really simple, eco friendly, sustainable soap alternative for the washing machine.

Step one: collect your conkers

You’ll need about 50g of conker soap granules per load, that’s about 4-5 conkers, so at two loads a week that’s just over 5kg of conkers to last the year. 

Horse chestnuts (Aesculus hippocastanum), not to be confused with sweet chestnuts (Castanea sativa), aren’t native to the UK. But they have been here since the 16th century. They are very often found in parks and ornamental gardens, they’ve also been planted alongside some roads in towns and cities. 

They have palmate leaves that are prone to being attacked by the horse chestnut leaf-mining moth (Cameraria ohridella). This means the leaves often look like they are turning for autumn before any of the other trees around. You can therefore identify horse chestnuts with a fair level of accuracy from a good distance by this alone. 

It has been a very good year for conkers this year, and the trees have produced loads.

Step two

The saponins in conkers need heat to release them. To release them faster and more effectively a high surface area is also useful. Chopping, blending, and grating are options I’ve experimented with. Our very small blender wasn’t up to the task, a tougher one would, I expect, be fine. Chopping the conkers up by hand made me lose the will to live.

We have a Mouli grater, where you turn a handle, and can process a number of conkers at once. This also meant that there was no chance of grated fingers. This worked really well. It’s a great option to take to the woods and show groups. For my next batch, the full year long supply, I used the grater on the food processor. 

I didn’t shell the chestnuts as I don’t own any clothes that are whites. A little bit of the shell escaped into the machine when I strained them through a sieve (I now use a cafeteria). I think it is responsible for some slight brown stains on a cream pillow case.

If you have a lot of whites you might want to shell your chestnuts. With a better straining process (I use a cafeteria now) I’ve not had any further issues with staining. In fact it did a wonderful job at almost fully removing a red wine stain in just one wash.

To de-shell the conkers easily, the best advice I’ve found, is to cut them into quarters then leave to dry for a few days. Remove shells once semi dry. Drying creates a larger gap between the shell and the nut, so makes this much faster. Then process as usual. 

Step Three

You can use your soap straight away. If you want to store it, lay it out in shallow trays in a warm, dry space – an airing cupboard or near a wood burning stove is ideal. 

Scoop about 50g or 150ml of conker soap granules into a jar and pour boiling water on top. Leave for 10 minutes and you’ll get a thick Horlicks like ‘juice’. Strain this off, through a fine sieve, and pour into the detergent dispenser in your machine.  I’ve been using a cafetière to make this process faff free. It can be poured straight into the machine and only produces one bit of washing up.

You can keep a batch of the conker soap in the fridge for up to a week, but I’ve found as it’s easy to do, I just soak and strain some for each wash.

I’ve tried experimenting with getting a second batch of soap out of the conker soap granules by pouring more hot water over them and I still got a thick creamy mix on my second run. I haven’t noticed a change in the quality of the washing coming out, even when it‘s been very muddy. But to be on the safe side I’m going to use this on less dirty washing.

The conker soap has no smell, so if you want add a few drops of your favourite essential oil to the mix. Or add dried herbs (watch out for colour) to the dried soap and pour the boiling water over both. 

I wash my clothes on a cold wash and therefore recommend the boiling method for extracting the saponins as conkers need heat to extract the saponins. There is some literature about adding the mix in a muslin bag into your machine, but you’ll need to wash on quite a hot wash to make this effective. 

Step Four

After use just place the conker soap granules into the compost, home or commercial.

I’m drying about 7kg of conker soap granules at the moment and without a dehydrator it is taking some time, but I’m trying to move our busy household off detergents. 

Every little helps. So if you don’t have the time to do a mass load and dry it all, still consider making some use of conker soap. One week’s washing done this way, is almost 2% of your yearly washing. One month’s washing is almost 10% of your yearly washing. So a few little changes can really start to add up.