natural cleaning

Home and Garden, Natural Cleaning

Everything To Know About Castile Soap For Cleaning

Here is everything you need to know about castile soap for cleaning. From what this natural cleaning product is exactly, to the many uses of castile soap, where to buy it, and more.

Castile soap is an incredibly versatile type of soap, that has a whole host of uses around the home. In fact, one bottle of soap could replace many cleaning products in your home.

While you may have heard of this natural cleaning wonder, you might not know how best to use it. Don’t get in a lather – let me talk you through everything you need to know about using this soap for eco-friendly cleaning applications.

Everything You Need to Know About Castile Soap For Cleaning

Image of castile soap beside a sink and a spray bottle, with a blue text box that says everything you need to know about castile soap for cleaning.

From what this wonder soap is, to how to use it, and what not to mix it with – here’s almost everything you could ever need to know.

In order to help support the running costs of Moral Fibres, this post contains affiliate links, denoted by *. Moral Fibres may earn a small commission, at no extra cost to readers, on items that have been purchased through those links. This income helps keep this site running.

What Is Castile Soap?

Castile soap is a vegetable-based soap that’s made without synthetic ingredients or animal fats.

Traditionally made from olive oil in the Castile region of Spain – hence the name – this non-toxic, natural, vegan-friendly, and biodegradable soap is available in bar or liquid form. Personally, I find the liquid form to be more versatile. However, with a little effort, you can melt bars down to form liquid soap, making solid soap bars a good option if you are looking to eliminate plastic from your life.

Whilst traditionally made from olive oil, the soap is increasingly being made with coconut oil. Occasionally you’ll find it made from castor, hemp, avocado, walnut, or almond oils. Whatever oil it is made from, it is these rich oils that give the soap its lathering and cleansing properties.

What Are The Uses of Castile Soap?

homemade cleaning wipes made with castile soap

Liquid castile soap is very versatile and can be used in a huge variety of ways – from naturally cleaning your home to your body. You just need a small drop – the soap is only ever used highly diluted – so one bottle can go a long way.

For example, a tiny drop – just two teaspoons – makes this all-purpose DIY cleaning spray. This spray is effective in cleaning every nook and cranny in your home.

You can also make this stone-safe homemade cleaning wipes solution (pictured above). Again, this recipe just requires two teaspoons of soap.

Even your makeup brushes can benefit. This makeup brush cleaning solution requires just one teaspoon of soap for naturally clean brushes.

I also use it to make liquid hand wash, floor cleaner, and laundry powder, among many other uses. For these recipes, and lots more uses for castile soap – try Fresh Clean Home – my book on how to make your own natural cleaning products.

Not convinced? Dr. Bronner’s – the main brand when it comes to castile soap – claims their soap is an 18 in 1 product. They say you can use their soaps for washing your face, body, hands, and hair. You can also use their soap for brushing your teeth, for shaving or for bathing, and for aromatherapy. But it doesn’t stop there. You can also use their soap for rinsing fruit, washing dishes by hand, doing laundry, mopping floors, for all-purpose cleaning, washing windows, and scrubbing toilets. They even say you can use their soap for washing dogs, controlling dust mites, ants, and aphids.  Phew. It’s a lot of uses.

Is It A Disinfectant?

bar of soap beside sink

Castile soap is a cleaning agent. It acts as a surfactant. This means that when you wipe a surface with the soap and water, it removes dirt and grease, as well as germs and bacteria from surfaces. Like most cleaning agents, these surfactants don’t kill germs – it just allows you to wipe them away.

Soap surfactants like this work because soap molecules have grease-gripping properties. When mixed with water, these molecules attract and capture dirt and other types of non-water-soluble molecules.

Soap and water are generally enough to clean most of your home and keep you and your family healthy. Public health bodies recommend that soap and water are effective when washing our hands to prevent spreading germs. The same is true of our homes.

Antibacterial or disinfectant products, on the other hand, aren’t cleaning products. They don’t clean anything. They kill germs, but don’t necessarily remove them. There are also concerns that overuse of antibacterial products can contribute to the rise of bacterial resistance to antibiotics, so it is best only to use these products when necessary.

Antibacterial or disinfectant products are useful when you want to clean surfaces where raw meat has been prepared, or for cleaning hard surfaces during Covid. In this case, then soap is best used in tandem with an antibacterial spray to kill any lingering germs. I like using these plastic-free refill anti-bacterial sachets* for no-fuss zero-waste germ killing. 

What Shouldn’t You Mix?

Don’t mix castile soap with acidic natural cleaning products such as vinegar or citric acid. This is because castile soap is alkaline. If you can remember from school science lessons, when you mix an acid with an alkaline a chemical reaction occurs and a new substance is made, or you end up with a neutral solution.

In the case of mixing castile soap with vinegar, the reaction neutralises both, reverting the castile soap back to its original oils.

In simple terms, if you mix castile soap with an acid, you’ll notice the castile soap curdles. It will also feel very oily. If you use it on your hands or on any surface, you’ll notice that it leaves a white film that is very difficult to remove.

If you want to get fancy, this oily curdled outcome is called unsaponified fat. This means the vinegar has reverted the soap into its raw materials. Castile soap isn’t much use in its raw material state, so I wouldn’t recommend mixing it with acid.

If you do want to mix soap with vinegar, use washing-up liquid instead. Washing-up liquid is much less delicate and can withstand being paired with vinegar.

Where to Buy Castile Soap

Castile soap is easy to find. Find bottles in most health food stores, or buy online. You can also buy branded Dr. Bronner’s liquid castile soap at Big Green Smile in a variety of sizes and scents*. These range from 60 ml if you just want to try it out, all the way through to 3.8 L bottles.

If you would prefer unbranded and unscented soap, then try Etsy’s selection*. Here you will find unbranded and unscented soap at a lower price point. If you are using it for making your own cleaning products, then you can add your own scent with essential oils.

For solid soap bars, you might be able to pick these up in health food stores or some larger supermarkets. Online, try Feel Unique, who have a large selection*.

Got any more questions that I haven’t answered here? Leave me a comment or drop me an email and I will aim to update this post with your question and answer.

Looking for more green cleaning inspiration? Check out my ultimate guide to making your own natural cleaning products.

Home and Garden, Natural Cleaning

Where to Buy Citric Acid for Cleaning

Wondering where to buy citric acid for cleaning or for bath bomb-making? Here are my top places for picking up this staple green cleaning supply.

To help support the running costs of Moral Fibres, this post contains affiliate links, denoted by *. Moral Fibres may earn a small commission, at no extra cost to readers, on items purchased through those links.

As a naturally occurring acid, found in a variety of fruits and vegetables (although increasingly derived from fungus to help meet increasing demand), citric acid is an environmentally friendly cleaning powerhouse that is used in many natural cleaning applications.

Food-safe, easily biodegradable, vegan-friendly, and a renewable product, there is so much to love about citric acid for cleaning.

As well as being a key ingredient when it comes to making bath bombs, citric acid is also fantastic at descaling limescale. Use it to naturally descale your kettle, dishwasher, washing machine, and iron. It’s also incredibly effective at cleaning your toilet. Citric acid’s powers don’t stop there. When you make a citric acid cleaning spray, then it’s great at tackling soap scum and hard water deposits too. And it has de-greasing, anti-fungal, and anti-bacterial properties. In short, citric acid is an eco powerhouse.

However, you might be wondering where to buy citric acid for making these cleaning products? Here are my top places to seek out this wonder ingredient.

Where To Buy Citric Acid for Cleaning & Bath Bomb Making

Image of chopped up lemons on a chopping board, next to a bowl of citric acid, with a blue text box that says where to buy citric acid for cleaning and for bath bomb making.

Citric acid is a common ingredient in home brewing and in Asian cuisine. This means if you have a homebrew shop or an Asian supermarket near you, then you may be able to pick it up locally. If not, then here are my favourite places where you can buy citric acid for cleaning and for bath bomb making online.

My top tip is that if you are in doubt about how often you are going to use citric acid, opt for a smaller amount. You can then work out how quickly you use it, and if it would be more economical for you to buy a bigger pot next time around.

Ethical Superstore

Ethical Superstore sells a 250 g plastic-free box of citric acid for just £2.10*. It is a limited selection. However, I tend to add a box to my basket if I am buying other ethical or sustainable goods. Ethical Superstore also sells other green cleaning ingredients, such as bulk bicarbonate of soda and liquid Castille soap. This makes it a useful place to pick up the cleaning supplies you need.

Buy Citric Acid At &Keep

Like Ethical Superstore, plastic-free retailer &Keep has limited options when it comes to buying citric acid. However, if you are shopping here for other plastic-free and ethical goods, and just need a small amount for general eco-friendly cleaning purposes then I wouldn’t overlook it.

Their citric acid* is plastic-free and unlike the boxes of citric acid that you can buy, this comes in resealable packaging. What’s more, the bag is home compostable once you have used it all up. It comes in a 750 g size, and costs £5.95.

Big Green Smile

Big Green Smile sells a host of green cleaning products, and supplies to make your own cleaning products. As such, citric acid is widely available to buy here*. Find it in 500 g sizes in plastic-free cardboard boxes or paper bags, from just £2.10. And if you need larger quantities, you can buy citric acid in up to 2 kg sizes for less than £25.

Buy Citric Acid on Etsy

Whilst Etsy is the go-to place for items made by crafters, many people forget that it’s also a great place to pick up crafting and cleaning supplies. Indeed, you can pick up citric acid on Etsy*. I’ve found it here in sizes ranging from 100 g to 2 kg. Here prices start from £2.50 up to £16.99 for 2 kg package sizes. Many sellers also offer free postage.

I would say Etsy works out better value for money for buying larger amounts of citric acid for bath bomb making, rather than smaller amounts you might need for general green cleaning.


Whilst I try to avoid Amazon on the grounds of tax avoidance, human rights issues, and environmental issues, I understand that not everyone is able to.

If Amazon is the most accessible option for you, then Amazon does sell citric acid*. Here you can find buy citric acid for cleaning in container sizes ranging from 250 grams for small-scale usage, up to a whopping 25 kg, and every size in between. Whilst it would be unlikely you would need anything above 500 g for cleaning purposes, the larger volumes would be suitable perhaps if you are making bath bombs. Especially if you are planning on making bath bombs on a commercial scale.

How To Store Citric Acid

Citric acid has a long lifespan. When stored in a cool, dry place, then unopened it should last for around five years. Once opened, it should last for around three years. If the citric acid you buy comes in a cardboard box, I recommend decanting this into a labelled airtight jar to help prolong its lifespan.

Looking for more information on citric acid, including how to use it and the safety concerns to consider? I’ve written a post on almost everything you need to know about citric acid, that might be useful reading.