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How To Make Homemade Soap From Ashes

how-to-make-homemade-soap-from-ashesThere are a few things you just don’t want to live without.  Soap is definitely one of those things. Whether you want to be prepared for a disaster, are interested in cultivating lost arts, or are really into DIY everything, making your own homemade soap from ashes is a great skill to have.  Since I have a steady supply of ashes from our wood stove, I figured it was time to learn how to make my own soap. I followed the directions from Grandpappy’s Homemade Soap, it’s very thorough.  If you are big into prepping I highly suggest you print it out for future reference.

Homemade Soap Ingredients And Supplies

Making soap only requires three essential ingredients, ashes, rainwater, and fat.  The type of fat doesn’t matter much, you can use lard just as easily as you can use coconut oil.  This type of soap won’t be exactly the same as soap you purchase from the store, or soap made from lye crystals.  It will softer, and a little more oily.  It also won’t bubble, commercial soaps have additives such as sodium laureth sulfate that are foaming agents.  Even though it’s not bubbly, it’s still great and cleaning things, and as some people can find sodium laureth sulfate irritating it’s nice to have soaps without it.

Heads up: If you are looking for a hot process soap recipe that doesn’t require you to make your own lye, you may want to check out the e-book Hot Process Soap Making: How To Make And Customize Your Own Natural Soap.  It includes step by step directions with pictures and tested recipes.

You’ll also need a stainless steel pot, a glass measuring cup, a long handled spoon, and molds to pour the soap into to harden.  I used plastic tubs from my recycling bin as molds, but really you can use anything as long as it is at least an inch or so deep.  A thermometer can also be useful.

How to Make Lye From Ashes

To make concentrated lye water you need to pour rainwater through cold ashes, hardwoods are best.   You need a plastic bucket or clay flowerpot with a hole in the bottom.  Cover the hole with a layer of pine needles to keep the ashes from falling straight through.

Tightly pack your ashes on top of the pine needles.  Ten cups of ashes will make about a gallon of lye water.  I was an overachiever here and filled my whole bucket.  Make sure to leave a few inches at the top to hold the water.

Next you need to set your bucket up so that the water can drip down through the ashes, out the hole in the bottom and into your stainless steel pot below.  I put two boards across a couple of five gallon buckets and placed the bucket of ashes so the hole drained between the boards.  The pot sits below.

Heat the lye water

If you have rainwater, heat it to boiling.  You can use steam distilled water, but regular tap water has too much chlorine and minerals in it.   Pour a half gallon of the boiling water over the ashes.  Once that has seeped down, pour another half gallon and wait 30 minutes before pouring another half gallon into your bucket.  If you don’t have a gallon of brown lye water in your pot, pour another one half gallon in 30 minutes.

You are done pouring as soon as you have a gallon of brown lye water in the pot below your ash bucket.  The used ashes should be discarded, you can put them in the compost bin to break down.  If you need more lye water, repeat the process with fresh water and ashes.  Ten cups of ashes and one and a half to two gallons of rainwater will make an average strength lye, so there’s no need to test the strength.  The finished soap will vary a little in strength, but you can use slightly stronger soap for laundry, and slightly weaker as a bath soap if it varies too much.

Concentrate the lye

After extracting the brown lye water the next step is to boil it until the lye is more concentrated. When starting with ten cups of ashes, you should boil the brown lye water until you have just 3/8ths of a cup concentrated lye water. Obviously I ended up with more then that, due to my overambitious bucket of ash.  This should take three to four hours.  Once you get down to about a quart of concentrated lye water in the pot you should watch it carefully so as to not boil off all your water.  If you do go below 3/8ths of a cup, carefully add enough rain water to bring it to 3/8ths.  Be very, very careful with the lye!  Wear gloves, and be super careful not to splash or spill!
Make Homemade Soap From Ashes @ Farming My Backyard

How To Make Soap From Homemade Lye

Making your own homemade soap from ashes is so easy once you have your concentrated brown lye liquid.  Start with the ratios below, and keep notes on how your batches turn out so you can make minor adjustments for future batches.  If you’re looking for a recipe that’s reliable every time (but where’s the fun in that!)  I suggest picking up a copy of Hot Process Soap Making: How to Make & Customize Your Own Natural Soap.

Here’s how to get started with your homemade soap using the lye you made yourself!

  • Warm up two cups of grease in a small pan on low heat.  You can easily render your own lard or tallow from pork of beef fat.
  • Pour 1 cup grease into stainless steel soapmaking pot
  • Slowly add your 3/8 cup concentrated brown lye water and stir for three minutes
  • Add another cup of grease and another 3/8 cup lye water and stir for fifteen minutes
  • Keep the soap warm (between 90 degrees and 130 degrees depending on what type of fat you are using.  You can place a towel over the pot when the heat is off.
  • Stir vigorously for one minute at a time, letting the soap rest for 10-15 minutes between.
  • Watch for the soap to be a solid cream or light brown color with no streaks before stirring, and is thick like pudding.  This can take 30 minutes or up to 3 hours.
  • Check for tracing by drawing a line with your spoon.  If you can see the line, the soap is done.  Or you can drop a little of the mixture from above, if the drop stays on the top for a moment it is done.
  • Pour into molds and cover with a towel to hold in warmth
  • Remove the towel after the first day and let the soap rest for six days
  • Remove the soap from the molds and cut to size
  • Air dry for 2-6 weeks, rotating halfway through.
  • Store finished soap in an airtight container, or wrap in plastic

What if Your Soap Doesn’t Work?

When I tried, I couldn’t reach a trace state and got fed up with the lack of action, so I just ignored it for about the next five days. I’d check on it a couple times a day, stir the lye and oils together, get mad and leave it again.  I don’t really think it benefited the soap at all to be ignored. Nor did it hurt its feelings, so all I really accomplished was feeling annoyed every time I looked at my “failure”.  Finally, I needed my pot back, so I began troubleshooting based on the instructions on Grandpappy’s website. I heated the oil and lye mixture and it came together a little but I still wasn’t achieving a trace state like it should. I added in more lye and almost instantly the mixture began to thicken up.

At this point I started jumping around the kitchen and shouting “I made soap! I made soap!” Then I came to my senses and poured it into my molds. (Well, the plastic food containers I was using as molds. Before this, they were watering cans for the kids.  Before that they sprouted seedlings for my garden. Before that they held leftovers, and before that…. well you get the idea).

 Troubleshooting your homemade soap

BUT, here’s how to fix some potential problems without leaving a pot sitting around your house for a week and glaring at it. (That doesn’t work anyway).

  •  Your mixture has a layer of grease on the top.  Make sure it is warm enough to  liquefy the grease.  If it’s cold, warm it up slightly.  If it is already warm, heat it a little more add 5% more lye water and stir for 10 minutes.
  • The mixture isn’t thick within three hours.  Heat it a little, turn off heat, add 10% more of the melted fat and stir for 10 minutes.
  • Your soap doesn’t harden.  Make sure you used hardwood ashes, not softwood ashes. (I did this, oops!).
  • Brown water pools under your bars during the air dry phase. Pour it off and add 10% more fat to the next batch.
  • The finished soap has a thin layer of white dust on the top.  Just rinse off this extra lye with water before using.
  • The finished soap doesn’t work well the first time you use it.  Dip in water and air dry several times to help it adjust.

My first attempt never hardened because I used the wrong type of ashes.  It still made an amazingly effective dish soap.  The soap was soft and gloppy, but the dishes were super clean.  It also did awesome things for my cast iron pans.  We burn mostly softwood in our wood stove.  One of these days I’ll try making homemade soap with the right type of ashes.  😀

Have you ever made homemade soap from ashes?  How did it turn out?

Sources: Grandpappy’s Homemade Soap Recipe and How To Make Soap From Ashes

Looking for a no fail hot process soap recipe that is customizable and all natural?  Or maybe you like making your own soap already, but wished you had some more step by step tutorials on using clay, scents, and textures?  Check out Hot Process Soap Making: How to Make & Customize Your Own Natural Soap

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Friday 14th of May 2021

Oh my word, I can relate so well to the paragraph “Before this, they were watering cans for the kids. Before that they sprouted seedlings for my garden...” the curtains become the shower curtain which becomes a dress which becomes a skirt... it never ends!

I think I am going to attempt soap making soon and we burn softwoods as well. I hear adding salt can help it harden. We will see!!!


Saturday 15th of May 2021

Ooooh, that would be great if salt helps!

Pauline Macey

Sunday 17th of January 2021

Hi, we have had 3 unsuccessful attempts with sheep lard and wood ash lye water using 3/8 cops lye to 1 cup melted lard. We had the temperature at 120 degrees both and in a water bath stirred for over 3 hours last time, but no trace . Can you help.? We are keen to give it another try.


Tuesday 19th of January 2021

I would try the egg float test to make sure your lye was concentrated enough.

Danny Mellema

Sunday 3rd of November 2019

Hey, I was wondering if you went for hard or liquid soap? Because I read somewhere that potassium hydroxide - from hardwood - is for liquid soap and sodium hydroxide for hard soap bars. I would like to know if it is possible to make a soap bar from potassium hydroxide.


Monday 4th of November 2019

I haven't successfully had a batch harden up with homemade lye, so yes I think you would need sodium hydroxide for a bar soap.


Saturday 29th of September 2018

I have a question, could I make a batch of lye and add it to my laundry soap to give it more kick?


Wednesday 3rd of October 2018

Lye is very caustic, and actually isn't present at all once the soap goes through the saponification process. I don't recommend using it.

Dana Mennerich

Saturday 7th of April 2018

tried this myself and ended up adding my lye water and it stiffened up instantly maybe too much and looks lumpy. it's been curing for a few weeks. trying another batch tonight but with crystals that i cooked down but the crystals are not dissolving very well and i'm stumped. is there a way to test the lye water for specific gravity so you always have the same concentration? getting dry potassium hydroxide from wood ash is very hard to do, it doesn't want to give up the moisture!


Monday 9th of April 2018

Would the egg test help? Here's an article with some testing methods.