Make Castile Soap At Home With Grocery Store Ingredients

A simple recipe for Castile Soap that you can make in the kitchen using ingredients from the grocery store. Basic soap-making skills will be learned from trying this recipe.

Making soap at home is a rewarding and fun activity. Although it may seem daunting at first, if taken step by step, you will find it is no more difficult than baking a cake. Once you have mastered the few skills needed, you will be able to whip up a batch in an hour or so and will never have to use store-bought soap again. You will also have wonderful gifts for friends and can even develop this hobby into a home-based business.

There are many fine books available for making different types of soap. Some of them are very basic and some are quite technical. It is not necessary to be able to perform higher math functions in you head to produce excellent soap. Should you want to experiment and create new recipes, a little math helps, but calculators are still sold everywhere, so don't worry. However, this is getting way ahead of ourselves. As a first-time soap maker, you are going to follow a simple recipe and you are NOT going to make any changes. This is not the time for experimentation. So, rein in that creative streak and give it a go.

Soap is a result of a chemical reaction that occurs when fat and lye are mixed together. You do not have to understand why this reaction occurs nor will you be asked to explain it later. Be happy that it does work and that you can take all the credit for this nifty little exercise in better living through chemistry. Your friends and family will develop a new-found respect for your scientific perspicacity and be impressed with the luxurious soap you are producing.

There was a time when home-made soap had a rather poor reputation because it was invariably made from lard (not a recommended fat choice) and lye of uncertain strength. The resulting product was smelly, harsh, and often left a nasty and persistent rash after use. This soap was made only to save money, using the cheapest ingredients available. Today, it is possible to make exceptional soaps in your kitchen, using exotic ingredients, easily obtainable at local shops or through the mail. Once you have mastered the few simple skills required, you will never again feel tempted by Crab Tree & Evelyn.

Castile soap is one of the simplest fine soaps to make. It requires only three ingredients, two of which can be found in the grocery store, and tap water. This recipe produces a mild soap that lathers lavishly and does not leave your skin feeling tight. Cocoa butter can be added for super-fatting, and essential oils for scenting, and, while not absolutely necessary, both are easy to find and add greatly to your finished product.

This recipe was carefully developed so that it is not necessary to handle the lye very much. The entire can is used, so you will not have to worry about measuring out all but an ounce or two. Please follow the recipe exactly and do not make any substitutions. If you do this, you will make wonderful soap the first time you try.

Before you begin, you will need to assemble a few simple tools and your ingredients. The key word here is "non-reactive" so every thing will have to be either stainless steel, glass, plastic, or wood. NEVER use aluminum or cracked enamel pots for soap.

You will need:

A stainless steel or enameled pot large enough to hold all the ingredients

A glass container for the lye

Something to stir the soap and lye with, wood is good for soap, heavy-duty plastic is best for the lye.

A plastic-lined box or storage container to mold the soap

A meat thermometer for the fat and a candy thermometer for the lye solution

Castile Soap

1 12-ounce can of Red Devil or other lye

32 ounces of tap water

48 ounces of pure olive oil (NOT virgin)**

Optional ingredients:

2 ounces cocoa butter or extra olive oil

2 Tablespoons lavender oil


Gather your lye crystals and set them in the sink. Slowly add the crystals to the water in a glass container, stirring with a sturdy plastic spoon to aid in dissolving the lye. This is a VERY caustic and HOT solution, wear rubber gloves, open the window for ventilation, and please be careful. Once you get past this bit, the rest is relatively hazard-free.

While the lye is cooling, put all the fat and olive oil in your non-reactive soap pot and heat gently until it reaches about 98 degrees on the meat thermometer, then try to keep it at this temperature. In the meantime, the lye will have cooled somewhat and you will be able to hasten this by setting the container in cool water. Your objective is to get the lye and fat to the same temperature of approximately 98 degrees. Do use a glass candy thermometer to check the temperature of the lye solution. Don't be obsessive about it.

When the optimum temperature is reached, slowly begin pouring the lye solution into the fat, stirring all the while. Please don't slop the lye onto your skin, take your time and work carefully. Once the lye is thoroughly combined with the fat, you should no longer have to worry about accidentally burning yourself.

Tip: If you use a fruit juice bottle with approximately a 2-inch opening, you can punch two holes at opposite sides of the lid. When you are ready to pour the lye solution into the fat, screw on the lid and pour through one of the holes. The opposite hole will let air into the bottle and the lye solution will come out in a thin steady stream.

Continue to stir this mixture for 20 minutes to an hour, until you can see a trace on the surface when you drag the spoon across it. Once you see this happen, you will always recognize it. Formation of the trace indicates that saponification has begun.

Once you see the trace, it means that the lye and fat are being combined chemically into a new compound, soap. Heat is a result of all chemical reactions and you will notice that the temperature of your soap pot has increased. This is good! One of the secrets of making easy and perfect soap is to allow the reaction to exhaust itself so that all the free lye is combined into the soap. If the pot is allowed to cool down too fast, you will still have soap, but the un-combined lye will precipitate out as a film of lye crystals on the surface of the bar when is has cured for awhile. You can choose to keep the reaction going or deal with it later. The best solution is to keep it going until all the lye is incorporated.

If you make your soap on a warm sunny day, cover the pot and wrap it in a black plastic bag. Set the pot in the sun for several hours. If this is not practical, cover the pot and place in the oven at the lowest temperature setting and leave the door cracked. Try to keep the pot at about 120 degrees for several hours.

If you skip this step, you will have to shave off the free lye before using the soap. Otherwise, you will burn your skin. French milling is another solution and involves grating the hard soap, adding water, and re-cooking it. Both of these solutions require extra steps later and are easier to avoid by allowing the reaction to exhaust naturally.

When you are satisfied that the reaction is complete it is time to add any super-fatting ingredients such as cocoa butter or extra olive oil and essential oils for scent. If you are using cocoa butter, melt it first and then stir it into the soap along with the fragrance oils. As the soap will be very warm now, stir for awhile until it thickens and you can see the trace again. Pour the soap into the previously prepared mold, cover with a lid and wrap the mold with blankets. You want the soap to cool very slowly so put it in a warm and protected spot.

The next day, you can uncover your new soap and inspect it. It should be firm and glossy on top. Castile soap gets very hard, so you will want to cut it into smaller bars while it is still soft enough to cut without shattering. Allow these small bars to cure for about 30 days before using. This is the most difficult part of soap making, waiting for it to cure before the first use. Be patient and remember, soap gets better with age, as long as it is kept dry it will continue to improve. Soap does not spoil.


* Ask the meat manager to save beef and/or lamb fat for you. Have him grind it if possible. To render, put the fat in a pot with several cups of water and cook until you have a pot full of clear yellowish oil with browned cracklings at the bottom. strain through muslin or several thicknesses of papertowel. Measure and store in fridge or freezer.

** Olive oil comes in many grades. For soap making, the least expensive grade, pure or pomace is preferred. It is actually easier to use and is much cheaper.

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