Cold process soap tutorial

Safety in the first place

• Prepare your workplace and keep it organize.
• Educate your family and special care with young children.
• Be sure you understand the process.
• Wear rubber gloves and safety glasses.
• Never leave the hot oil unattended.
• Never leave the soda and soda solution unassisted.
• Work with method.
• Do not get distracted at work.
• Clean up spills immediately.

 Formula

This is a basic formula for a soap by cold process. The balance of oils provides a great soap with moisturizing feature, hardness, dense and abundant foam and durability (lasting) excellent.

Equipments

The safety equipment, goggles and gloves are essential and should always be used in handling of raw materials and the process.

I used a microwave to melt and heat the oil, the containers are plastic-type PP (polypropylene). To prepare the solution of caustic soda use a stainless steel container and heat the solution, use an electric heater or stove. It is not advisable to use plastic or glass and microwaves to heat the solution of soda. There is always a potential risk of accident! Important also, never use aluminum container for handling caustic soda – the soda reacts with the aluminum!

The kitchen scales can be perfectly used to weigh the components. Most of them are accurate to 1 gram, enough for normal weighing. Care to buy or use a scale measuring the response requirement. It has many scales of poor quality that does not have a suitable speed (response) measurement, avoid these.

Technically any kitchen mixer can operate to accelerate the beginning of the saponification reaction. It is recommended a minimum power of 100W and ideally be over 150W, which would allow working with a larger amount of mass. Remember that the greater the power, the greater the weight of the device, which tires more and get faster if the trace, which is not always desired. In place of the mixer can use the traditional wired beater (fouet), requires more time and effort.

Mold preparation

Mold to produce 24 standard bar of dimensions 90 x 60 x 25 mm and weighting 130 g. MDF made with 18-mm double-sided coated white. The sides are removable through three handler with screws on each side.

Mold mounted with sides close

This polycarbonate sheet is used to adjust the mold to the exact dimensions of bars of soap, avoiding a waste to cut later.

Lining the mold

There are three pieces of waxed paper that will coat the bottom, top and sides. The market has a type of baking paper which is siliconized called glassine  but does not serve as a lining because the soap mass glue in the paper, difficulting to removal. The waxed paper can be found in stationery stores that sell stuff for engineers, is used to make sketches.

Is used solid vaseline to fix the waxed paper inside the mold.

In the first fix lining the bottom e start to lining the sides.

Using spatula make the corner lining.

Overlap a little in the final.

Mold lined and ready.

Preparing the vegetable oils

Weigh teh palm oil in a plastic 2 liters recipient .

Weigh the babassu oil.

Mix the both oils.

Weigh the castor oil.

Weigh the olive oil in a plastic 2 liters recipient.

All oils is ready.

Mix the castor oil in the mixed babassu and palm moil.

Melting palm and babassu in microwave, +- 2 min in high.

Heat the olive oil +- 1 min in high.

Mix al oils in a plastic 4 liters recipient.

Preparation of lye solution

Weigh the sodium hydroxide (lye).

Weigh the water in a stainless steel or glass or plastic recipient.

Add lye into the water slowly while stirring. Never add water over lye! It may cause a violent reaction with the potential for an accident.

Initially the solution becomes turbid but after a few minutes becomes clear. Allow to cool

Preparing the colorants and essential oils

Weigh red iron oxide pigment and titanium dioxide.

Weigh about 50 ml of oils mix in a mortar.

Dispersing the pigment with the using the mortar. Inorganic pigments such as these are in the form of agglomerates which if are added directly into the soap mass, may not mix well and can forming color spots.

Weigh the essential pols of Geranium Africa, Palmarosa and Rosewood.

Process – preparation

Add the pigment mix into oils mix.

Using the mixer in high speed, mix until uniform color.

Let stand to eliminated bubles.

Good pigments dispersion, color is uniform.

Process – cold process start

 Adjust temperature of lye solution to 40+-1°C, the process temperature.

Adjust temperature of oils mix to 41+-1°C.

Add lye solution into oils mix with mixer manual (off) agitation.

At finish lye addition start the agitation with mixer on.

Use cycle of 3 x 10 sec on / 3 x 20 sec off.

The viscosity increase, that is signal of trace starting. Slowly add the mixture of essential oils with manual mixer (off).

Here we have the medium to heavy trace. The drip is not incorporated easily in the soap mass.

This is the ideal spot for the soap mass to be placed in the mold. Must work quickly because the viscosity increases very rapidly making it difficult to pour the soap into the mold. To avoid this bad handling, better stop at the light trace.

Pour immediately into the mold, work quickly.

Spread well

Knock the mold on the surface of the table to level the soap mass.

Ready!

Place the lid and wait 18-24 hours for the saponification reaction is complete transforming the oil and lye in soap.

Start removing the soap off the mold.

Remove the sides.

Slip the soap block out off the mold.

Remove the lining.

Removing the lining side.

The soap block is ready to be cut.

Cutting the soap block in two loaf using vertical cutter.

Each loaf is 90 mm wide. The vertical cutter was build to cut this dimension.

The soap block length is 305 mm.

Two loafs measuring 305 x 90 x 60 mm.

Multiply cutter to cut the loafs.

This cutter give us high productivity, is good for high production.

Cut 12 bars simultaneously.

Each bar measure 90 x 60 x 25 mm and weigh 130g.

We can use the individual cutter, is a versatil and simple.

Cut each bar at a time. Has a cutter guide to regulate the dimension.

The guide.

Drying the soap

Soap bars are drying in this wood rack.

The drying time is about 3  to 4 weeks. The soap loss aprox. 8% of water.

After drying time the soap is ready to use.

Total of 24 bars with 130g.

Quality control

After 48 hours of drying withdrawing an aliquot sample from the bar-sample to check the pH. This bar-sample is stored as the sample counter-sample.

This aliquot sample withdrawn is dissolved in water.

One can use pHmeter to measure pH. The chemical nature of the soap confers alkaline characteristics to products. All soap, industrial ou handmade, are alkalines.

An alternative is use the pH paper.

Some example of cold process soap

Thanks!!