Q&A for How to Make Lye

Lye is indeed toxic and can cause burns if not handled properly. It's crucial to be extremely cautious and well-informed when working with lye, especially in soap-making. Before diving into soap making, it's essential to thoroughly research and understand the properties and safety measures associated with lye. Always wear gloves and goggles, especially if you're a beginner. Lye is highly caustic and can cause severe burns if it comes into contact with your skin or eyes. 

No, you cannot use coal. Coal is pure carbon, and will not work the same way as wooden ashes will.

No, but a wooden barrel will be the best choice. If you must use another material, make sure that it isn't aluminum, as this will react negatively with the lye.

The coconut fronds are a good source of potassium. Coconut shells should also yield potassium. Using these as a potash source would yield KOH, potassium hydroxide. It is a substitute for NaOH, sodium hydroxide.

Wear rubber gloves and eye protection. Never add water to lye, as it will boil and splatter.

Yes, you can. However, clarify it a few times during this process, by boiling then cooling and letting the sediment settle, then pour clearer liquid for use and repeat.

If you boil down the resulting liquid, you should have a white residue. The liquid itself will probably be the color of whatever you put into it.

Any hard wood will work. Softwood doesn't work because there is too much resin and not enough potassium.

Lye will eat through plastic.

You can boil the resulting liquid to get a lye powder. The sodium hydroxide is in solution, and by carefully evaporating the water you can get the pure powder form. But be careful as sodium hydroxide (lye) is quite corrosive to aluminum and dangerous to the human body.

Pipes in your home are poly vinyl chloride (PVC), which may be susceptible to lye damage over a long period of time, but this depends on the concentration of lye and the contact time. When you clean your drains (with lye), either they are backed up with water, which dilutes your lye, or they are slow draining, which means the lye does not spend as much time in the drain. Either way, it is safe for use with PVC drain lines.

By wood, I am assuming you mean wood ash. Wood ash is the agitator in the process. Use as much as you can, but leave enough space in the barrel so you can add enough water to completely saturate the mixture into a slurry. Draining the watery ash out every few days or so and repeating the addition of ash and water is called leaching. This makes the concoction more potent.

Oak trees are definitely hardwood trees and when burned will yield hardwood ash.

Newsprint paper is derived from treated pulp and yields a black carbon ash with residual sulfites. It has no value for this operation..

That depends on the potassium content of your plant material. If your material is highly concentrated, a week or two perhaps, although it may take a few attempts at leaching, 3-4 weeks, to produce KOH lye.

Most of the websites I've reviewed use a 30% mass concentration for the solution. Take the amount of lye required, divide by .3, which represents the total solution weight. Then subtract the mass of the lye required to get the required water weight.

This method makes potassium hydroxide, KOH, which can be used as a substitute for NaOH.

Drain it through the cork at the bottom of the barrel. Drain when the raw egg floats slightly in the barrel.

CaOH is used in the food industry to process sugars, purify water, and break down other food components for industrial purposes. It is non-toxic, but is still caustic like NaOH is. NaOH is toxic and can be used to unclog a drain. Don't use NaOH for any food processing. For example, breaking down food oils with CaOH and say a dog eating the resulting soap won't kill him. NaOH and food oils also makes soap, but if your dog eats it, he can die. Do not eat CaOH soaps, they won't taste very good.

Caustic soda is another term for lye, so you already have it. If it is a powder, consider it crystalline lye and follow recipes that use that.

You can use any kind of bucket, but I would avoid aluminium buckets; aluminium will react with the lye compound and alter the resultant product.

You can use sand, or even natural and untreated fabric, such as hemp, linen, or cotton. The filtering is only important to catch ash and debris from polluting your collected lye solution. Remember, any substitutes must be resistant to the corrosive nature of the lye and not add any unwanted contaminants.

Yes, but you will need to adjust the ratios of all the ingredients.

No, the lye will eat up the salt and it would just dissolve.

Yes, technically, but you wont get any potassium from the charcoal, as it is pure carbon. Charcoal is extremely valuable in gardens, to make activated carbon using peroxide, and as a fuel source. I would separate the ash from the charcoal and get the best uses out of both products, as the charcoal will just dilute the ash.

No; seashells are calcium carbonate and don't contain potassium.

Lye, also known as sodium hydroxide, has many uses and is more typically found in drain and oven cleaners. It can also kill grass and weeds, though precautions should be taken. It is not an ideal weedkiller as it can harm the user if spilled on skin and it is harmful to more than the weeds, so it disturbs the local biota.

Any hardwood ash, preferably white ash because that ash has the most potassium in it.

The percentage of potassium in potassium hydroxide is 69.7%. [MW of potassium/MW of potassium hydroxide x 100] or that is [(39.1/56.11)x100=69.7].

Yes it can be deadly. It is best to use in moderation for optimal results. Alternatively, try using acidic cooking ingredients, such as vinegar to neutralize the alkalinity.