Wood Ash Lye

Hi, I am new to soap making, I still have yet to make my first batch. I have been researching but can't seem to find the information that I'm looking for. I am hoping someone here can help me out.

My attempt for soap making is to use homemade lye. I have made lye using hard wood ash. I tested it using the egg and it proves to be lye.
All recipes and calculators talk about lye as a crystal or powder with water being added to it. My lye is already a liquid so this doesn't apply to my case.

My question is, what is the conversion rule for replacing crystal or powder lye and water with ash wood lye (liquid) in a recipe?

Thank you

Hi, and Welcome!

I admire your courage. I sort of get the whole "do it like the pioneers did" mentality. However, I also must inject a word or two of caution.

First, wood ashes gives potassium carbonate (potash) and sodium carbonate (soda ash). When you add acids, I think both will produce carbon dioxide that will off gas.

While both are alkaline, they are not the most efficient alkaline substances to make soap with. They WILL hurt you if allowed to touch skin, however. Use safety equipment. Also, wood ash lye gives paste soap, I think you have to cook it for extended periods of time to get bars. I am not sure, so you need to verify this with someone more knowledgeable than I. DeeAnna may be able to help here.

Second, while you did the egg test, it is not the most accurate method of knowing how much alkali is in it. Any answer we give may or may not be the correct one due to poor measurement of alkalinity.

We use a water percentage of 38% for bar soaps. I would start with that, and be prepared to adjust as necessary.

I think it might be good to know how to do this for when "TSHTF." However, the results will be questionable due to not knowing how strong is your lye. That is how you figure the amount of oils and fats to add. As Susie said, floating the egg tells you that you have lye. It just does not give you a precise measurement.

In usual situations, the exact amount of water is not overly important - it has to be enough to dissolve all of the lye but not too much to make proper emulsification too hard (the Castile thread has more on that!). In your case, your liquid is a certain concentration of lye, but without knowing what concentration it is, you cannot tell how much of the solution to use.

If it is a 75/25 water/lye mix, then you will need more of it than if it is 55/45. If the recipe calls for 150 grams of lye, you need to know how strong the solution is in order to be able to put that much lye in.

Is there a special reason why you are making it and not buying it? To get used to soap making, I would get some lye and get used to soap making AND THEN look at using the home made stuff at a later date. At the moment you won't know what is causing an issue and you have a massive unknown element in the mix with this homemade lye..................

there are a few links online on making woodash soap[ http://www.frontierfreedom.com/joomla/index.php?option=com_content&task=view&id=105&Itemid=1 ] . there are a few people on a few forums that does it on a regular. it's not impossible to do , i would recommend a good in-depth research to fully understand all the steps involved . . . tip my hat to you for your courage , hope all goes well

Thank you for your responses!
Yes, I'm a bit of a 'Start at the guts' kinda person, never quite happy with slipping nicely into anything. 42 years of the city life and convenience to gardening, canning, raising hens and butchering my own meat in less than 8 months. 3 years later and I'm paving my path for homesteading but I've yet to make soap and what better way, than like it was done once upon a time.

I did, of course read up alot before making the lye as I know it can be dangerous if not handled properly and with safety percautions. I also know that trial and error to perfect it will be in store but I need a base line to start with. What I was hoping to make is more of a liquid soap, a castile soap.
Now because I don't know the concentration of my lye in percentage, is there a way to find this out?
Thanks again

That link Lion of Judah gave does show a chart of how much lye solution to how much oil. I would get and use a pH meter ASAP, before making soap. I am not sure I would want to stick my tongue on something made with ashes to zap test.

"...is there a way to find this out?..."

Sure. When you actually have a lye solution (potash leached from wood ash is not a lye solution -- it is a mixture of potassium carbonate and possibly some sodium carbonate if your ashes come from plants near the sea or other salty place), you can titrate the solution with an acid of known concentration and figure the alkalinity directly. Or you can use a hydrometer (device for measuring liquid density) -- the egg is an imprecise hydrometer -- as an indirect, less accurate measurement.

When using wood ashes, the general method used "way back when" was to react the leached solution (mostly potassium carbonate) with slaked lime to convert the solution to a solution that is mostly caustic potash (KOH). Decant the caustic potash liquid from the calcium carbonate precipitate. Measure the alkalinity of the liquid at that time. Add an approximate amount of the caustic potash to a fat mixture. Cook the mixture while stirring continuously, test on the tongue for zap (excess alkali), add more lye if needed, cook the soap mixture some more, test for zap, etc. until the cooking soap mixture is clearly and consistently zappy which indicates saponification is complete. The resulting soft soap can be treated with brine (table salt solution) and cooked some more to partially convert it to a sodium soap. The results of this process are generally lye heavy and variable in quality.

There's a reason why soap makers gratefully and willingly converted to using caustic soda (NaOH) when it became commercially available in pure form in the mid 1800s.

Another comment -- using pH to determine the endpoint of saponification is not going to be too accurate, since any excess alkalinity AND the intrinsic alkalinity of the soap itself combine to create the pH of a soap. That pH will vary depending on how much excess alkalinity is present and what kinds of fatty acids were used to make the soap. One really needs to measure excess alkalinity directly to ensure the soap is properly saponified. The zap test is a time-honored measure of excess alkalinity that was used as far back as the 1800s and earlier. Yes, the idea doesn't set too well with some people, but the only real alternative to the zap test is an acid titration to determine alkalinity. I'm going to stop at this and let well enough alone.

I used to make soap this way and it would take your hide off! I am very thankful for the great quality lyes we have today, much easier and consistent to use.

As DeeAnna said, if you want to make it like they did in the old days, then you will have to do a salting out process at the end - the chances of you making a lye heavy soap is very high unless you accurately measure your solution scientifically, but then you're not doing it in the old way, which is the whole point. Salting out (there are better explainations on how to do this on this site than I can give, so I won't try) was used to remove the excess lye from the soaps.

I will again reiterate my thoughts that learning to make soap with regular lye to begin with will mean that you know how making soap in itself works. If you're learning to make soap and using this homemade lye, you won't be able to problem solve effectively - is the issue with your process or with the lye?

"... it would take your hide off!..."

That's part of the reason why "grandma's lye soap" got such a bad reputation. Even my grandma's homemade lye-and-lard soap (made with commercial lye) was used only for laundry. Grandma Goldie used store boughten soap for the bath.

Even commercial soap makers in the 1800s routinely sold lye-heavy soap for most purposes. Only soaps specifically intended for toiletry purposes were made with more attention to minimizing the excess alkalinity. Some of the old manuals I have read talked about the chapped and reddened faces of folks who didn't have the money to buy fancy toilette soap for bathing. Can you imagine the terribly irritated hands of the ladies who hand-washed laundry for a living?