Index:

1. History
2. Handcraft soap making
3. Water and other liquids
4. Alkalis
5. Oils
6. Oils properties
7. Oils saponification values
8. Soap calculation
9. Soap calculator
10. Essential oils
11. Additives
12. Bibliographic references

 

History 

When speaking of soap and soapcraft always begins with the history of soap. The internet hosts dozens of such history, how it all started. Some very fanciful and others that make sense. Everything goes back to thousands of years ago, the last speech that read was 2800 BC in Mongolia! Pity the Plinio the Elder in ancient Rome and his Naturalis Historia, if he knew there were people making soap so long.

Interestingly, the origin of the word soap and the date and circumstances of its discovery are not known with precision. Many scholars believe that the discovery was accidental and the name is attributed to a Roman legend. The fact is that the word soap is similar in several languages: Sapone (Italian), Savon (French), Seife (German), Saippua (Finnish), Szappan (Hungarian).

Simmons Appleton and the classic book Soap Manufacture, 1908 mentioning in the introduction, the use of soap could be a measure of a nation’s civilization. Of course, this is an affirmation of the early 20th century and coated with a dose of discrimination. The key factor is personal hygiene. The soap helped in the process of awareness of personal wellness through daily ritual hygiene, bathing. The outstand Aleppo soap, produced in the city of the same name in Syria, made from olive and laurel oil, has history since the 1100s, era of the Crusades, the Christian paramilitary movement. How this soap manufacture developed and prospered in the city of Aleppo, which remained from generation to generation until today? Who were the clients of Aleppo soap? The Crusaders were the customers. Yes, the Crusaders, for over a century, the long journey from Europe to the Holy Land, stopped in Aleppo to wash, to make hygiene using soap Aleppo, before following and enter Jerusalem.

If we look at the study of health and well being of humans, we come across three words that are representative of the historical dimensions of evolution. Cleanliness, hygiene and purity, stacked on each other tell the story of evolution, this Neolithic ancestors worshiped already looking good, order and beauty, until recent times. The first extract, the foundation, which is cleaning up what is the side and feed all of us, is linked to the survival instinct. Purity is something that was done, manufactured by man since ancient times, as a certain psychology that produced refined or supernatural religions, ideologies of divine perfection that were imposed to our animal nature and the material world. Hygiene derives from Greek classics to characterize human welfare in order to preserve and prolong life. A single product line and closely associated with cleanliness, purity and hygiene, is the soap. As the master Marcus Siviero, said – “soap our of each day!”

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Handcraft soap making

As a matter of clarification, I define here what I consider handmade soap manufacture. Are all activities performed without use of machinery, where a soap in solid or liquid form is produced from the primary components, which are oils and alkalies, by means of a chemical reaction of saponification. I do which is called soap manufacture and craft natural vegetable, i.e., not employing any animal, with the exception few components such as beeswax and goat milk, and obviously no petrochemical derivatives. Important to note that the activities with the use of glycerin bases, very popular, is a form of crafts handmade soap but not soap manufacture. As you can see in the topic about chemistry, the product of the saponification reaction is soap and glycerin. In the soap industry glycerin is removed from the process (by-product) for having a high commercial value, rather than the primary product, soap, and sold as raw material for the chemical industry. All industrial machinery processing soap was designed with this principle of withdrawal of glycerin.In all handmade soap the glycerin that is produced in the saponification is maintained in the soap which gives the wetting properties of hydration to the skin characteristics of glycerin. This does not happen with industrial products tend to dry out and harm the most sensitive skin. The difference is remarkable! Ironically, today with an excess of glycerin in the market due to increased biodiesel production, which also produces glycerin by transesterification, the industry rushes to review its processes but the state of the art technology and the costs do not facilitate this work.

Raw Materials

Water and other liquids

Water is most commonly liquid used to make soap. Can be used distilled water or treated water, potable tap water. Goat milk is used when you want to make a goat milk soap. Other liquids are used the same beer and wine to exotic soaps.

Alkalis

Are used sodium hydroxide (NaOH) known as caustic soda when either one hard soap and potassium hydroxide (KOH) known as potash when one desires a softer soap or liquid. Both are chemicals controlled produxts and therefore there is a limited amount that can be purchased per month for individuals. The control is more rigorous in potash. Buy, especially soda, from suppliers suitable why there tampering, particularly with sodium chloride, the salt. Use what has minimum concentration of 97%.

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Oils

There is a plethora of oils and fats that can be used in the preparation of soap. Theoretically any vegetable oil or animal could be used for all fatty acids have in its constitution that react with the alkali generating soap. The choice of oils is subject to the properties you want in the soap. Brazil is a privileged country with unique varieties of oils from the Amazon, most of them with medicinal properties. Andiroba, copaiba, cupuaçu, buriti, Brazil nuts, murumuru, are part of this magnificent type of oils.The base oils, which are those most commonly used are: olive, castor, sunflower, canola, coconut, babassu, palm kernel and palm. These oils allow the essential structure for formulating soap, optimizing their properties. The oils that impart special characteristics, called modifiers oils, the most used are: jojoba, shea, cocoa and sweet almonds.

Oils properties

The properties of an oil which impart characteristics to soap are given by the fatty acid composition of each constituent oil. In the table below are the composition of fatty acids and their properties to the key oils used in soap manufacture.

Conditioning refers mainly to emollient and humectant caracteristics to skin. Humectant agents increase the water content of the top layers of the skin by drawing moisture from the surrounding air. Emollient agents act as lubricants on the skin surface, which give the skin a soft and smooth appearance.

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Palm and palm kernel oil 

A recurring question about the oils is palm oil. Many questions arise with large quantities of palm oil on the market. Palm oil, palm crude oil, refined palm, palm olein, palm stearin, palm organic, palm kernel oil, are the designations referring to oils obtained from the fruit of the palm Elaeis guineensis, also known as dende tree. The Elaeis guineesis is native in tropical regions, about 10 degrees above and below the equator. In Brazil, in the Amazon region, with large areas of cultivation in the state of Pará  and Amazonia and to a lesser extent in Bahia.

The largest producers are Indonesia, Malaysia, Nigeria and Colombia. Brazil occupies a position of 13 ° global producer.

A peculiar feature of the fruit of the oil palm is that it produces two types of oil: from pulp (mesocarp) is extracted the palm oil and kernel the palm kernel oil (PKO). The fatty acid composition of these oils are completely different. In palm oil predominate palmitic and oleic and in palm kernel oil, lauric and myristic, it which is very much similar to that of babassu and coconut.

The pulp and consequently the crude palm oil has a yellow to orange-red attributed to the amounts of carotenoids in fruits and also at the level of oxidation that has undergone the fruit to be kept stored before being processed.

Palm fruit processing: extraction and refining

Extraction

The extraction process typically follows a flow as drawn bellow. The final product is the extraction of crude palm oil, with its characteristic red color of fruits and almonds that are prepared for the extraction of palm kernel oil at a later stage. This crude palm oil reddish color, is what is called dende oil, widely used in the regional cuisine of Bahia. Brazil and some countries in Africa are the only ones who use crude palm oil in the cooking.

Palm oil is composed of two main fractions: olein, the liquid fraction and stearin, the solid fraction. At an ambient temperature of 25 ° C both fractions coexist.  It’s easy to separate olein from stearin with a simple fractionation process with temperature variation.

The amount of carotenoids (such as beta-carotene which acts to prevent shortage of vitamin A) present in crude palm oil range 500-2500 μg / kg according to the degree of ripeness of the fruit from the genotype which is extracted.

The crude palm oil also has the so-called minor constituents which can be fatty acids, phosphatides, esters, aliphatic alcohols, tocopherols, pigments and metals traces. Much of this can be eliminated with refining of palm oil. In the state of Bahia, the cities of Nazare and Valênça. are several small producers. The most striking feature of this production of crude palm oil is its rustic mode extraction by pressing in so-called “rodões” stone, a rudimentary process, which is not observed with care the fruit at harvest and transport which ultimately causing a serious oil acidification, which reflects the high heterogeneity of the product

 Refining

There are two processes for refining palm oil. The most recent process is the physical, it is highly effective and lower cost. The alkaline process uses sodium hydroxide in the neutralization and is a disused process for large scale production.

The final product is the refined palm oil internationally known as Palm Oil RBD (Refined, Bleached and Deodorised).

After the process of refining palm oil can undergo a fractionation by crystallization under controlled temperature resulting in a liquid phase, called a palm olein and a solid phase, called palm stearin. The olein is used in general frying and stearin in industrial frying at high temperatures and also as margarine and shortening taken the advantage of not requiring hydrogenation (no trans fat).

PKO extraction

The extraction follows the flow above and is a physical process, without the use of solvents.

Palm oil and the soap manufacture craft

With its high content of palmitic, palm oil gives the ideal soap hardness. With the exception of cocoa butter and shea butter, which contains high amounts of palmitic and stearic, the palm oil is the only allowing, at a reasonable cost, good hardness to soap.

Technically, any form of palm oil can be used to make soap. See the table below which no significant differences in the composition and SV are all equal. (Note the olein and stearin are table RBD).

I note however that I made two batches of crude palm (olein + stearin) using two oils of different brands purchased at stores of tipical foods and, after a while, white spots appeared on the surface of the soap. This defect is known as DOS – dreaded orange spot, which is caused by oxidation of the oil. This oxidation is probably caused by minor constituents that I mentioned above, present in crude oil and also the rudimentary process and lack of care in the extraction. The soap made with palm oil always has a yellow light whose intensity depends on the amount used.

The palm stearin because of its high melting point (above 50 ° C) may become unfeasible process for cold process temperature would be too high.

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Oils saponification values

All oils have a saponification value (SV), which is the amount in mg of potassium hydroxide (KOH) that react with one gram of oil. SV is important because in the formulation of soap  with SV is possible to calculate, for a given amount of oil, the quantity of alkali necessary for the reaction.

Below is a table with the SV of major oils used in soap manufacture:

Soap calculation

Consider the example below, how to calculate amount of sodium hydroxide required for a given amount of a mixture of oils to make soap.

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Soap calculator

To facilitate the calculation of soap are soap calculators. In internet several options are available. I usually  use this one of Majestic Mountain Sage, very easy to use.

First you fill the data in its formulation (Recipe Title), your name (Created by). Choose the unit of measure, in our case is gram (grams), the type of alkali. If you’re using an alkali solution, complete concentration (Liquid Lye Solution).

Go on the table oils and fill the quantity field in front of each oil and click it at the foot of page to calculate (Calculate Lye).

The result appears on this page. Field (Table Lye NaOH) is the result of the quantity of soda required. On the right side (% excess fat) 0 (zero) means no excess oil and 10, means 10% excess oil. It is always good to work in the green region. I usually work with a 5% excess oil. This is so for security reasons. With excess oil you will always have a product within a safe range of alkalinity, pH. The quantity of liquid (Liquids) has a working range. Usually use, for 100 grams of oil, 32 grams of water. Recalling that the higher the water content, the longer the time to obtain the trace, and the soap takes longer to dry.

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Essential oils

It is almost mandatory to use essential oils to fragrance the soap by cold process. The essences, which are synthetic products do not work in the cold because it contains alcohol which causes what is called “seizing”. The mass of soap increase the viscosity quickly and the rection is accelerates difficulting  handling and placing the mold. Essential oils are very expensive, they come to represent 35-60% of the cost of a soap cold. The amount you use is typically about 6% over oil. In the hot process it is possible to use essences for adding the fragrance is done at the end of saponification. Also the hot can decrease the amount of essential oils.

Additives

The additives are components that have a specific function well in soap and are typically used in small amounts. Can provide color pigments and clays prevent oxidation with natural preservatives, reducing the pH with natural acids, etc..

Colorants

Three features should be considered in the choice of materials to give color to soaps made by cold process. The coloring materials must first be inert to the skin, i.e. must not cause any adverse reactions in contact with the skin. Must be resistant to alkaline saponification reaction of the cold process and should be light resistant, must not fade and lose the color when the soap is exposed to light.

To meet the first requirement, the best option is to use materials approved by the FDA (Food and Drug Administration) U.S. for use in cosmetics. Combining this with the others requirements, there are few alternatives and usually fall in the class of pigments, most inorganic and synthetic.

• Iron oxide – black, red, yellow, ocher
• Ultramarine – dark blue, light blue and violet
• Chrome oxide – light green and dark green
• Titanium dioxide – white
• Zinc oxide – white, light red (calamine)
• Ferric Ferrocyanide – Dark Blue
• Mica – pearlescent effect of various hues

These class of pigments are those approved by the FDA are resistant to cold process and will not fading with time.

These pigments are hard to be found in small quantities that are used in soapmaking. An alternative that I use is to buy these pigments in shops selling art materials  – the painters use to prepare their paints. They are sold in small packages, less than 100g, costly but yield much but you can buy sharing with other crafters. I use of trademarks Sennelier (French) and Mahler (fractionated in Brazil).

Besides these pigments can be used clays that have no tinting strenght as pigments but are easy to be found in the colors white, green, yellow and pink, these two latter mixed in its preparation, with iron oxide. For black color option you can use of bamboo charcoal that besides the strong tinting strength has its skin conditioning properties.

Another option is to do your own coloring, by maceration of certain plants with oils that are commonly used in cold process. An example is the macerating green tea or herbal mate to obtain a light green color. Some components of the formulation itself may give a slight color to your soap, as the honey will give you a cream or the use of goat milk that depending on the cold process temperature can give a cream or dark brown or ocher.

Important to emphasize that most dyes which are used in food and coloring candles are anilines (azo components) that are not resistant to alkali and also has not resistance to light and hence should not be used to impart color to the soap. In this case it is always good to test before.

A final observation concerns the question of natural versus synthetic pigments. If you are a nattural soapmaking and waives only use materials of natural origin, it is understandable that you will not use a synthetic pigment (man-made). Turns out the FDA approval only synthetic pigments because the natural may be contaminated with heavy metals (toxic) that can not be separated in their extraction and actually do some harm to health, such as lead and cadmium. The choice is yours!

On the download page I put files with a list of materials approved by the FDA for use in cosmetics and also the catalog of artistic Sennelier pigments. In both are marked pigments that can be used in cold process.

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Natural antioxidants and preservatives

The typical natural products such as handmade soaps, creams, body oils, balms, can deteriorate over time. This impairment may be caused by oxidation of oils and / or by the formation of bacteria and fungus. The products which inhibit or retard these defects are antioxidants and preservatives.

Antioxidants

Many have probably heard of or even seen a defect that occurs with the oils in general, oils for cooking. This defect is the rancidity of oil along the storage time, denoted by the characteristic smell of rancid oil spoils. This defect can occur even with soap crafted, it is rare but can occur with soap made with certain oils, such as grape seed oil and which have in their formulation a high value of superfatting above 8%. The rancidity is an oxidation process where the free radicals formed by the light and air attack the unsaturations present in polyunsaturated oils, such as grape oil.

Preservatives

In products with a reasonable amount of water, and in water based creams is very common the formation and growth of microorganisms which eventually spoil the product. In these cases it is always necessary to use some type of preservative. In anhydrous or products with very little water is usually not necessary this precaution.

 

Natural antioxidants and preservatives

There are three elementary products that technically may be considered effective antioxidants: oleoresin rosemary extract (Rosmarinus officinalis leaves), vitamin E (tocopherol) and extract from the seeds of grapefruit (Citrus grandis).

Rosemary Oleoresin Extract – ROE

Distillate of leaves of rosemary oil resin is perhaps the most effective antioxidant this class. Importantly it is not essential oil of rosemary, which does not have antioxidant properties. Herbaceous has a slight odor which may be masked when mixed with other fragrances. ROE is oil soluble and should be mixed in the oil phase when preparing creams, lotions and balms, etc.. It is usually sold at concentrations of 2 and 5% and the amount recomentada is 0.1 to 1% to 2% and 0.05 0.5% to 5%.

Vitamin E

This is the oldest and well known of all the antioxidants. Was the first to be introduced, not only as an antioxidant but also as a moisturizer. As the ROE, vitamin E is oil soluble. There are two types of Vitamin E: Vitamin E acetate (dl-tocopherol), which is synthetic and natural vitamin E (d-tocopherol). It is always preferable to use the natural by its greater effectiveness, alias, some authors claim that the synthetic does not have antioxidant, which is a controversy because the medicinal capsules of vitamin E are made with synthetic acetate. The recomentação amounts are 1 to 5% of acetate and 0.1 to 0.25% of natural.

Grapefruit Seed Extract – GSE

The newest anti-oxidants, prepared as grapefruit seed powder. Many people have used the GSE as a preservative against bacteria and fungus, but their effectiveness is not proven extensively. If you use, it is best to test before it largely depends on the formulation. As antioxidant recommended amount is 0.05 to 0.5% as preservative, and 0.5 to 1%.

Do not one elementary natural product which can be considered an effective preservative. The GSE could be considered a preservative despite the lack of unamimidade its effectiveness. There are some proprietary preparations usually consist of a mixture of natural components which has been disclosed as effective preservatives, among other properties. They are the Biopein ® and ® Neopein both from Bio-Botanica, which are extracts of various herbs and DERMOSOFT ECO 688 ® by Dr. Stratmans company, certified by Ecocert.

 

Antioxidants and preservatives in soaps by cold process?

In cold process soaps made by using conventional oils with a balanced formulation of oils, there is no need to worry about oxidation, it rarely occurs and the range of alkaline pH soap combined with low water content inhibits the formation of microorganisms. Therefore it is not necessary to use antioxidants and preservatives and product will keep for a long time without change – I have made soap for over three years and are perfect!

 

 

Bibliographic References

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