The formulae as given are for shaving sticks, and do not readily press unless thoroughly dried. A more satisfactory result is obtained by adding at the mill 25 per cent. of white tallow base to obtain a satisfactory mug soap.
Shaving powder differs from the soaps just described in being pulverized, usually adding up to 5 per cent. starch to prevent caking. Any of the above soaps, dried bone dry, with or without the addition of tallow base make a satisfactory powder for shaving.
Shaving cream is now a very popular shaving medium due to the rapidity and convenience with which one can shave by the use of this product. Formerly shaving cream was made from the liquid oils like olive oil and a soft fat like lard, together with cocoanut oil. Now, however, most of the popular shaving creams are made from stearic acid and cocoanut oil, as a far superior product is obtained by the use of these substances. By using these a more satisfactory cream is obtained, and it is far more convenient to make. The lather also produced therefrom is more suitable for shaving, being thick, creamy and remaining moist.
A few typical formulae for shaving creams of this type are as follows:
I. lbs. Cochin cocoanut oil 26 Stearic acid 165 Caustic potash lye, 50° B. 69 Glycerine C. P. 76 Water 38
II. lbs. Cochin cocoanut oil 18 Stearic acid 73 Caustic potash lye, 39° B. 54 Glycerine 33 Water 27
III. lbs. Cochin cocoanut oil 18 Stearic acid 73 Caustic potash lye, 39° B. 54 Glycerine 20 Water 40
Stearic acid 60 Glycerine C. P. 85 Water 165 Sodium carbonate 50 Borax 1
To make a shaving cream by Formula I or II, the cocoanut oil and glycerine are first put into a suitable mixing apparatus or crutcher, and heated to 120° F. A part or all the potash lye is then added and the cocoanut oil saponified. The rest of the potash lye and the water are then added, and with the mixer running the stearic acid, previously melted in a lead-lined or enameled vessel, is then poured in in a stream and the mass stirred until smooth, care being exercised not to aerate it too much. The cream is then tested for alkalinity, the best method being by that described under shaving soap, in which the sample is dissolved in alcohol. Because of the large quantity of water present, phenolphthalein is unsatisfactory, as dissociation of the soap may show a pink indication in spite of the fact the mass is on the acid side. For a quick method of testing the bite on the tongue is a satisfactory criterion. If a cooled sample bites the tongue more stearic acid is added until there is a 3% excess of this. When the proper neutralization has taken place the cream is perfumed and framed in a special frame, or it may be allowed to cool in the mixer and perfumed the next day. When cool the cream is strained, or put through an ointment mill, after which it is ready to fill into tubes.