What Are the Benefits of Using Excess Fat to Make Soap?


Handcrafted soaps with a little touch of essential oils and sweet, subtle fragrances can offer you a powerful bathing experience. While aroma enriches your mind, the excess fats, on the other hand, are the ones that enhance the overall impact on your skin. Whether made by a hot or cold process, adding fats is essential. 

Adding excess fat or superfatting of soap benefits the soap’s moisturizing ability. Another significant benefit is its compatibility with the skin’s pH. As the soap has a pH of about 9.5, and the skin’s pH varies between 4.5-6. Superfatting is used to make the soap more skin-friendly.

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Why Is There Fat in Soap?

The process of saponification involves oil similar to cooking, and also similarly to cooking, adding the right amount of fat and the timing is equally important. 

The saponification process is a chemical reaction wherein strong alkali and fat react. Fats obtained from either animals or plants are made up of ester molecules, better known as triglycerides. This molecule is made up of acids like oleic acid, palmitic acid, or stearic acid.

When they are mixed, the process of saponification commences. 

But, it’s crucial to know the number of fat/oil that is needed when making soap. If you fail at this part, your soap will most likely fail as well. 

The reason for that is, if you know the amount of oil you need, this will then decide the amount of alkali you require for the saponifying of that particular fat. Thus, adding fat is mainly an essential part of the saponification process due to the ester molecules. 

Neutralizing strong alkalis like KOH and NaOH is also essential to prevent any possible harm to the skin. This means that if you did not add enough fat to it and your soap has not saponified enough, the end product might irritate your skin. 

In order to know if your soap is ready and has gone through the process of saponification correctly, you can do the Zap Test for Soap. This test involves you sticking your soap to your tongue if it zaps, similar to the feeling when you’ll get a zap from a nine or 10-volt battery.

This means that it has not been saponified yet. This means or else you need to wait a little more, or it means your measurements were not correct. If that’s the case, it is best to wait 48 hours and do a test again. And if you still have the same problem, you know there is a measurement problem. 

You can also use a pH strip which is very easy to use. You simply put the pH strip on your wet soap to get a pH reading and that’s it.

What Are the Benefits of Using Excess Fat to Make Soap?

The addition of excess fats to the soap in the hot or cold saponification process is done after it’s cooked/traced. While physically, it doesn’t have any benefit, chemically, it does have mainly two benefits.

Moisturizing Ability

The first main and arguably the most significant benefit of adding excess fat is enhancing the soap’s moisturizing ability. Some strong soaps can be harsh to the skin as they cleanse away, even the skin’s essential moisture and oil. This can cause itchiness and dryness in the skin and thus can be damaging.

Here, superfatting makes sure that the soap balances it with its moisturizing traits and keeps the skin healthy. The excess fat content is increased up to 1-3 percent, which adequately curbs the harshness. 

Taming the Alkaline 

The natural pH of the skin is between 5.6 to 6 in the acidic range. However, soap mostly has a pH of about 9.5, which is basic as opposed to acidity. 

This gap in the pH ranges can adversely dry the skin and thus damage it too. To avoid skin irritation and close the pH gap, excess fats are added, especially in the cold process.

This excess fat uses up all the lye produced in the process of saponification. The soap manufacturing process is carried out according to the set saponification values.

Adding 1-3 percent of the excess fat is sufficient to control the alkalinity to this value’s margin. Thus, this prevents any unwanted reaction while the soap is made much more compatible with the skin’s pH.

What Fat Makes the Best Soap?

You can use particular butter, fats, or oils to make the best soap with a splendid moisturizing effect and aroma. These have exceptional abilities that offer a smooth effect along with superb conditioning to the skin. 

Also, they provide a refreshing and pleasant fragrance that can highly enrich your bathing experience and skin benefits.

Here are two of the best butter/fats that you can add to create your best soap.

NOW Solutions, Shea Butter, Skin Emollient, Seals in Moisture for Dry Rough Skin, 16-Ounce

Shea Butter

This cream-colored butter originates from the shea nut found in Africa. It is exceptionally soft and has a low content of saturated fat. Also, Shea Butter has a unique non-saponifiable property that inhibits it from merging in the chemical process. 

Thus, it does not react with the alkali during the process and retains its soft and delicate texture. Also, it has emollient capabilities and fatty acids like unsaturated oleic acid along with saturated stearic acid. 

NIVEA Cocoa Butter Body Cream 15.5 Oz

Cocoa Butter

Cocoa butter is commonly used in creams, moisturizers, lip balms, etc., because of its exceptional properties. This butter also has a fine smooth texture and can stay solid and stable at room temperature. 

It has a silky finish and remarkable emollient properties with a 3:2 concentration of saturated to unsaturated fat ratio.

How Do You Use Fat to Make Soap?

If you wish to use extra fat to prepare a gentle soap, follow the steps below.

Cut the tallow into chunks and transfer it to a large pot. Cover it and continue heating at a medium level flame and stir it occasionally and continue till it melts.

Add around the same amount of water to the fat after it cools down below the water’s boiling point. Once this mixture begins to boil, you can take it off the stove, cover it, and let it settle overnight.

Now, you must discard the fat gunk or any liquids present as you remove the fat from the bowl. Measure the rendered fat, cut it into chunks, and transfer the quantity (as per the calculations) to a larger bowl.

Next, you can take out all the other materials and start making soap. Don’t forget to wear protectors! Pour distilled water into a big non-metal bowl, transfer lye into it and mix it well using a wooden spoon.

After the lye dissolves, you can slowly add the chunks of fat, stir it well, and heat it if needed. Next, you can add additives, essential oils, excess fat, and mix the soap well. Once done, you can pour it into molds and let it harden. 

Now that your soap is ready, you can use it or store it for up to 3-4 months in cotton bags at a cool place.

Final Takeaways

Crafting soap the right way requires proper measurements and calculations of the ingredients used. Adding excess fats is not a compulsion, but it is advised to tame down the soap’s harshness. It makes the soap gentle on the skin and makes sure that the pH level is no longer harmful. 

So, go on and make your soap the right way with an adequate amount of excess fat!

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