Making Lye From Ash
I made a mental list recently of all the things I buy and put them into a category as to if I could do without or make them myself. For most things, I can.
One of the things I buy on a regular basis is soap. I have made my own in the past, but never entirely from scratch.
The reason for this is that potassium (or sodium) hydroxide, Lye, can be intimidating. Yes, there are ways to make moisturizing bars and the like without Lye, but these can never be soap. Excuse me while I put my chemistry background to work here.
Lye is responsible for a chemical process called saponification. In this process, the lye will change the actual oil molecule that is being used into soap and glycerin. This completely “uses up” the lye.
I work with caustic agents on a regular basis in the lab, but lye is not one of them. So, I decided to put some basic safety instructions together first. These apply to working with lye in general, not just making it.
PPE: Personal protective equipment takes some of the risk out of what could otherwise be a risky process, and I am sure was at times in the past.
Cover as much skin as possible. This means long sleeves and pants. Boots not flip flops.
Safety glasses are one of those things you should just always keep around. Yes, people have done without them for 100s of years. They also went blind occasionally. You do not want this splashing in your eyes, so just be on the safe side.
A surgical mask is not required. Try not to breathe in the fumes and if it makes you feel safer, a bandana or dust mask will work fine. You can find a 3 pack of washable dust masks here. Work in a ventilated area. Outside is best, but if you can’t, open the windows.
Mixing: Metal is not ideal for lye. Stainless steel is safe, if it really is stainless steel. Wood and plastic are ideal. Heavy duty or number 5 plastic will definitely stand up to it.
You do not want to pour water into lye, you want to pour lye into water. If you add water to premeasured lye is may expand too rapidly and cause a mess in the least and injury at most. You want to add the lye slowly to the water instead.
Clean Up: Keep vinegar on hand to rinse/ wipe down anything that came in contact with the lye. This will neutralize it. However, do not Fight Club a lye burn if you do get it on you. Vinegar will react with the lye and the base and acid will create a neutral. However, in getting there, there is a reaction between the two that produces heat. It will hurt like heck. Instead, flush with water for about 10 minutes. If it is bad, go to the hospital.
Okay, so that should be enough to safely move on. Here is how you can make lye water.
To make potassium hydroxide, you will need:
hardwood ash (softwood will not work), rain water (has to be soft water), a wooden barrel, straw and gravel.
You want to start with a wooden barrel. Drill holes in a small area in the center of the bottom of the barrel. This is a drain and you will be collecting the liquid from it.
Rinse and dry enough gravel to fill the bottom of the barrel to somewhere between 1 to inches. The add a 3 inch layer of straw.
Fill the rest of the barrel with your ash. This is usually collected over times and stored in a dry place, as it will take quite a bit to fill the barrel. You want to leave about a hand width of space at the top.
You will need to prop the barrel up. Blocks or a wooden frame will work, but be sure it will not be in any danger of tipping over. It needs to be high enough to fit your bucket (remember the safe materials above) under.
Next you will pour your water in. How much water you put in will be roughly what you get out. You want to get the ashes wet, but you do not want them floating. Also, be sure your barrel is protected from the rain, a tarp works fine if you need it.
It will take a couple hours before it has trickled through and filled a bucket. Be sure to be careful of spills and do not let the bucket(s) fill all the way up. They will not be a strong enough yet, so pour back into the barrel. Once all the water has gone through and been poured back in, it should be strong enough.
You can test the pH itself (You want it to be 13) or you can place a potato in the bucket. If it sinks, pour it back in. If it floats, you are good to go.
You can store it in a plastic container with a lid. Be sure to label it for safety.
With this lye water, you could make liquid soaps. To make hard soaps, you may have to concentrate it. This just involves reducing it by boiling in a stainless steel pot or wooden tub. No matter which you use, make sure it will be dedicated for this purpose, do not use your favorite stock pot.
I have heard of this whole process being done on a smaller scale in a clay pot instead of a wooden barrel as well. I think this is a great way to start if you are not making your whole years supply at once.
Soap is a necessity, so for me, this is a great skill to learn and can be perfectly safe if handled properly.