Low Waste Dishwashing and Laundry Soap

Low Waste Dishwashing and Laundry Soap

This post has been a long time coming. In part because there are so many different recipes out there for dishwashing and laundry cleaning products, and in part because many people have strong feelings about the right and wrong way to wash dishes and laundry and we are anxious about causing controversy!!

So, take this post with the disclaimer that this is what works for us, but if it doesn’t float your boat, don’t give up on homemade or zero waste alternatives because there’ll be someone else out there with a solution that works for you if ours doesn’t!

But to begin at the beginning…

We don’t buy pre-made, off-the-shelf cleaning products in bottles because we see the bottles as waste products. Even if they are recyclable, they are likely made with plastic, which is not effectively recycled for a whole host of reasons (especially in NZ), and even if it were, we are of the view that recycling is a last-resort that comes only after we have been unable to refuse, replace or reduce our consumption of products that come in packaging that is not reusable or refillable. As we can replace most store-bought cleaning products with homemade ones, we have eliminated the need to think about recycling empty plastic bottles.

Why not simply fill up your liquid cleaning products at a bulk store (i.e. reuse your bottle)?

Filling up a reusable bottle at a bulk store is definitely a step up from buying brand new smaller bottles every time we need new cleaning products. We started off doing this in our early days of living without a bin. However, we’ve phased away from this for two reasons:

  1. When you get liquid cleaning products in bulk to put in a BYO bottle, you get them out of a larger container. Probably a 20L drum/dispenser. By and large, most manufacturers of these cleaning products don’t take these dispensers back to refill/reuse once they’re empty (this is the case with Ecostore, for example, which is the brand we most often see in bulk/fill-your-own cleaning product aisles). So, the retailer/stockist is left to deal with the dispensers, meaning they either get chucked out (they’re difficult to recycle) or given out free to members of the community to re-purpose (which is probably only a ‘delay to landfill’ situation). Some manufacturers DO take their dispensers back; we’ve heard that Earthwise do if asked, and smaller manufacturers are usually keen to, like Klin Isi, Aroma Naturals or Prana+Therapy. However, whether your local stockist actually arranges for the bulk containers to return to these manufacturers is another question. It’s worth asking your local store to find out what they do – if they do return the dispensers to the manufacturer for refill, then from a zero waste perspective, you may be quite happy simply to refill your bottles at your local store (and therefore feel no need to read on through this post!!)
  2. It’s much cheaper and easier to make the stuff from scratch at home. Not only that, but you have a better idea of what is in your cleaning product in the first place.

So what do we do?

We make our dishwashing/laundry soap out of bars of castile soap.

Now, we could buy liquid castile soap, but this invariably comes in plastic bottles, and we don’t want them. So, we buy bars instead (packaged in paper or nothing at all), and turn the bars into liquid! You could use Dr Bronner’s bars, or, better yet, find locally-made + sustainably packaged castile soap, like Hopi (Wellington – Palm Oil Free), Aoraki Naturals in Timaru (who, in fact, also make laundry and dishwash bars! All Palm Oil Free), Clean Earth Soap (Golden Bay – we go for the unscented bar), and Hopi Soaps handcrafted in Kaikōura. See our regional zero waste shopping guides to suss out where you can get your hands on castile soap in your region. If you can’t find any in your region and instead choose to order from elsewhere in the country, make sure you ask about the materials used to wrap the soaps for shipping. If you know of any other NZ made, sustainably-packaged/unpackaged bars of castile soap (and where you can get it), leave us a comment below!

Here’s our step by step process for turning a bar of castile soap into dishwashing liquid.

Step 1: Take a bar of castile soap, like this one :

Step 2: Cut it into small pieces (no need to grate, just break it into dice-sized cube bits), like this:

Step 3: Put the bits into a HEAT RESISTANT jar (like a mason jar) and fill the jar to the top with boiling water. “How big should the glass jar be?”, you might ask. Well, we guesstimate a bit. Ours is about 750ml capacity. The bigger the jar, the more liquid your soap will be, the smaller the jar, the more solid your soap will end up (the size of the bar of soap also effects liquid to soap ratio).

Step 4: Leave the jar and its contents for 24 hours. Don’t look at it – you’ll just start to doubt that it could ever work.

Step 5: Twenty-four hours later, return and you should find that the pieces have fully dissolved and the content of the jar is one consistent blob (either liquid or solid, depending on the size of your jar). Your concoction will look something like this:

A bar of Hopi castile soap, post-melting!

Now what?

Option 1

For dishwashing soap or for handwashing laundry soap, stop at this point (that’s what we do because we are lazy).

How do you use it? You simply take a teaspoon of your melted castile concoction, like this:

Put this teaspoon blob at the bottom of the empty sink, pour some hot/boiling water over it and swish it around until it dissolves, then fill up the sink. Your soapy water is now ready for your dishes/handwash laundry.

Note that castile soap doesn’t lather up like commercial dishwashing/laundry liquid. This is probably for the best because all kinds of yucky things are put into detergents to make them do this, and actually bubbles don’t do much to really clean, they’re just cosmetic.

If you are travelling/going camping etc, Option 1 is a great dishwashing/handwashing laundry soap to travel with, just put a bunch of the mixture into a small jar and pop it in your suitcase – so easy!

Option 2 – to optimise de-greasing power

Take 1-2 heaping tablespoons of the melted bar of castile soap. Put it in another HEAT RESISTANT jar, add a teaspoon of washing soda (which you can buy in most bulk stores), and then fill up the jar with boiling water (ideally, for these kind of quantities you’d probably be looking at using between 350-500ml of water, any more than that and you’ll be getting too dilute). Leave it for 24 hours again to dissolve.

Note that option 2 works as BOTH a dishwashing liquid and a general laundry liquid. Yes, that’s right, you just made a two-in-one product, woo-hoo! HOWEVER, note that there are controversies about using soap (rather than detergent) to clean your laundry in a washing machine. We won’t go into it here, but suffice to say that if you are passionate about laundry, you may be best to stick to commercial detergents. This is probably especially wise if you are cleaning reusable nappies.

However, if you’re hand-washing fabrics, this homemade mixture (like option 1) should be fine as you can agitate the clothing/fabric sufficiently to ensure soap residue comes off.

If you are alarmed by our disclaimer about the homemade laundry liquid and have decided to continue buying commercial detergent, then we would recommend you ditch the store-bought laundry liquid (unless you can guarantee your local is getting the dispensers refilled) and use laundry powder instead. Either get laundry powder in bulk from a supplier like Bin Inn or look out for Eco Planet or Next Generation laundry powders in supermarkets and other stores because these products come in a cardboard container with NO plastic lining, and their scoop is made of cardboard too (not plastic). We’re also trying out soap nuts at the moment, with great success (though we recognise they are shipped in from far away and may not be the most sustainable long-term solution because of this). We buy SoapNuts NZ brand because it comes in a cardboard container with no plastic lining. Again, our regional shopping guides point out where you can get these in your local area.

Happy scrubbing!

Do you have any go-to low-waste recipes for dishwashing liquid or laundry soap? Let us know in the comments below!

26 thoughts on “Low Waste Dishwashing and Laundry Soap”

  • Hi Hannah and Liam

    Thank you for your inspiring presentation at the Nelson Public Library today on ‘The Rubbish Trip ‘. Fantastic! I’d like to add another R to the Recycling Mantra – Re-think, because that’s what we have to do first if we want to embrace the other 6 R’s. I’m on a mission to reduce waste in our household, have been for a while now, and after hearing you today there are some changes I can make – Dr Bronner’s here I come! Thanks again and keep up the good work. Veronica

    • Thanks Veronica. That’s a great R! There are other Rs that we think are pretty important too, but which aren’t in our triangle yet (for fear that our presentation will become very, very long, haha), like “Repair”! Some hierarchies have 11 or more. The Rethink one is quite right though because low-waste living does require a real mind shift. Good luck on your continued waste reduction mission. We are so heartened by the many people we meet who are already well on their journey 🙂 Nga mihi nui – H & L

  • Hi there. Sounds fabulous. I have wanted to make my own for a few years now, but have not been able to source Palm Oil free castile soap in my area (Hastings). Does Hopi have palm oil? Currently use Eco-Planet laundry powder ,at New World Hastings but would prefer to make own. Thanks, Clint.

    • Hi again Clint – great, we’ll add in to the guide now that Eco Planet is at NW Hastings. Hopi does not have palm oil. In fact, true castile soap should never have palm oil as it’s a traditional recipe (originally made for the King of Castille), requiring only olive oil, water and lye! You can get Hopi at Creative Treasures at 315 West Heretaunga Street in Hastings (according to Hopi’s list of stockists). You might also be interested in Aoraki Naturals’ products – have you heard of them? https://www.aorakinaturals.com/ Run by Lisa who lives in Timaru. She’s committed to being Palm Oil Free. They make traditional castile soap, but they also make dish wash bars and laundry bars (again, all palm oil free). Ship around the country (you’ll have to ask them about packaging, but pretty sure it’s mostly compostable cardboard/brown paper). Hope that helps!

      • Thank you so very much for your help. Great I will look into this most definitely . I have sent you a message re your Facebook ,thanks. Your awesome !

  • Hi Liam and Hanna, just come home after your introduction on zero waste, was very impressed and we have been wanting to do this, Thank You So Much. Alison and Sid Brown, Fairlie Community

    • Hi Alison and Sid – thank you so much for your lovely message. Thanks heaps for coming along to our talk in Fairlie. We were thrilled to speak there and really excited by what’s happening at Heartlands, Incredible Edibles, Soul Food etc. So great to read that you’ve been wanting to reduce waste further. We’re sure you were doing heaps already, but hope there were some useful tips in the talk too 🙂 Good luck with it – we wish you waste-reducing success!! H and L

  • Can you let me know if the products you use are setic tank safe as we live out of town. Lots of stuff interferes with the way a septic tank works and I always use products that have grey water or septic tank safe on them. Thanks, Fi.

    • Kia ora Fi,

      Do you mean the castile based homemade dishwashing liquid we make? The answer is yes, it is septic tank safe. Proper castile soap is environmentally benign and is made purely of olive oil, water and lye – the lye is sodium hydroxide but disappears in the soap making process. All soap bars have lye in them; it is necessary for the hardening/bar making process. All soap bars are made of a mixture of fat + water + lye. However, many commercial soap bars have other things added to them, from synthetic fragrances to preservatives etc. that are not only unnecessary but they aren’t effectively filtered out of wastewater and septic tank systems and can contaminate surrounding area where water comes out. True castile soap shouldn’t have any of those chemicals. The grey water that comes from dishwashing/laundry if you use castile soap is also safe to put on your garden.

      If you’re asking about whether Eco Planet’s laundry powder is septic tank safe (if you want to go for a detergent, non-homemade option) then yes, on its website it indicates it is septic tank safe. They do use enzymes that apparently can sometimes not go well with septic tanks. However, they say that it is safe for septic tanks, so should be good. Could be worth double-checking with the company if you want.

      Hope this helps – any other questions, let us know!

      H and L

  • Hi team, saw you in Picton and was super inspired, thank you! A question about your dish washing liquid recipe – I found it does an amazing job in my dishwasher, getting glassware nice and shiny and streak free, but not so much for handwashing dishes. Glass ware remains cloudy and it doesn’t cut through grease on pots and pans – any tips that have worked for you would be much appreciated. Cheers KP

    • Hiya Kat – thanks for commenting! Glad to hear that you’ve had success with the dishwashing liquid recipe in your dishwasher. If you are having trouble with the handwashing there are a couple of things we’d recommend trying. Keep the water you’re washing with really hot (as hot as you can handle), and/or when you rinse the glasses use hot water – heat helps when you polish glasses. Another thing you can try is a vinegar rinse for the dishes after you’ve washed them (so instead of rinsing just in water, use vinegar water to scrub off) – this helps to cut through grease. Don’t add vinegar to your actual dishwashing liquid recipe because acid will unsaponify the castile.

      If you have really greasy pots/pans, leave them to soak with water, baking soda and vinegar for a bit before washing them.

      Another ingredient that some people also add to their homemade dishwashing liquid is a couple of teaspoons of washing soda into the mixture too, for extra de-greasing power.

      Hope that helps! Keep us updated on how you go 🙂

  • Kia ora Laim and Hannah

    First heard of you guys in Feilding nearly a year ago. I look back now and wonder why I was so wasteful with our resources (and money!) … thanks for the insight. A query re laundry detergent/cleaner – some one said they put baking soda in their machine instead of laundry powder. Have you tried this or heard of pros/cons with it? Looking forward to trying the dishes detergent, thanks!

    • Thanks for your message, Lisa. Great to hear that you’re still having success with low-waste living, even all this time later. We love it and glad to share the passion with others too 🙂

      We have heard of people that use straight washing soda in the machine (not heard of straight baking soda but can believe that there would be people who do this). The washing soda peeps swore by this approach, but we haven’t personally tried (we still have a bunch of soap nuts we bought a while back and they’re working really well!). With the baking soda, we usually do a baking soda and water soak for clothes that are stained, prior to handwashing or putting through the wash. Am unsure how straight baking soda in laundry would work, only because we haven’t tried it. Also would need to look up how much to use for a load. Don’t think there should be any real cons. Lots of people are anti-soap in the laundry because it can slowly clog the machine, but baking soda shouldn’t do that (if anything, it should help unclog).

      Sorry we can’t be more helpful! We might need to do some experimenting 😀

  • Hi
    I’m just wondering whether the bar Castile soap could be melted in water like this and then used in soap dispensers as a hand wash? Or would it be too harsh?

    • Hiya Rosie – this should work though you might want to blend it up with a stick blender after following the melting process, just to get a more even texture that will work better in a soap dispenser. Castile would definitely be great for hand wash and not harsh. In fact, castile is kind of the opposite of harsh and it’s usually used for people with sensitive skin. Hope it works 🙂

  • Hi there, when you do option 2 and add washing soda, do you use the full diluted amount in your dish water or can you use just a portion of it? You have been really inspirational for me to find more ways to be waste free. Thanks.

    • Hiya – just a portion of it! not the full diluted amount. We haven’t done option 2 for aaages though as feel option 1 works well – especially now you can buy dishwashing liquid bars which work fine without the need to add washing soda (for example, Aoraki naturals’ or Watts good creations dishwashing bars).

  • Hi there, I was just wondering how long option 1 lasts / what the shelf life is like? I’ve heard it’s only a month?
    Also, if you were to use it in a dishwasher, would you again just put a teaspoon type blob into the compartment? Or is it not recommended for the dishwasher?
    Thanks! Jess

    • Hi Jess, To be honest we can’t see a reason why the shelf life would only be a month. We always keep ours as long as it takes us to use it up, which would usually be about 3 months or so for the quantity we make. It’s probably not recommended to use in the dishwasher. We don’t use a dishwasher so we haven’t personally tried making dishwasher tablets, but we have friends who use their own dishwasher tablets and apparently they are very cheap and easy to make! You might want to give it a google and experiment with some of the homemade dishwasher tablet recipes you find 🙂

  • I’ve just tried this but the bits of soap didn’t properly dissolve …. should I just leave it longer??

    • Hmm… could be the particular soap bar you used, or too much soap relative to water (we have this issue sometimes as we never measure things out as we are much too lazy for that, lol). If it’s just a few chunks that aren’t dissolved, just chuck the lot in a blender or nutribullet, or use a stick blender and blitz it, then pour it back in the jar.

  • Slow and steady wins the race, been wanting to make this since I heard you tell me about it. The seed was planted by you guys in early 2018…I’m ashamed to say i’ve only just made it. But Oh well I’m happy to say there will be no going back for me now. Thank you so much for sharing your knowledge and caring so much about our environment and continuing to inspire others.

    • No shame at all! Awesome that you tried it – hope you’ve found it works well. We found a dishsoap bar we really liked at the Nelson Environment Centre shop by KoruKai Herb Farm – Coconut and Lemon, you might want to try it 🙂 Thank you for all your support!

  • What is the benefit of dissolving the bar in water?
    Could I use the bar as is?
    I suppose it makes the bar last longer.

    • Kia ora Holly. You can indeed use the bar as is – in fact, it’s better that way. We just melted ours into a liquid because it was practical while living on the road (we didn’t want to carry around a soggy bar of soap). Also back when we made this stuff, you couldn’t really find dishsoap bars anywhere – now there’s heaps of them!

      You just need some sort of container or bag with holes in it to hold the soap in, e.g. those old school soap shakers (little metal cages), or an empty tin can with holes punched in the bottom, or even just a cotton produce bag!

  • thinking hard about this.
    i’ve been retaining rinse water,
    and for residential wastewater retention to work
    we don’t want to deposit sodium into the soil.
    potassium as a soil macronutrient is perfect for circular hygeine systems;
    though the first way to extract it is incinerating plant material.
    also not sure if we’re limited to liquid consistency,
    i’ve been loving powder soap as caustic soda for multiple purposes,
    and it ships with less weight for trade and distribution.

    my challenge to myself is
    how do i create a safe potassium based powder soap at home?

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