Soap from lard and tallow

In short

• Lye (NaOH) always goes into the water, never water onto the lye. Goggles, gloves, long sleeves, children and pets out of the room.
• The amount of lye is calculated to the gram for each fat separately. Scales accurate to 1 g are a must; cups and spoons are not good enough.
• The recipe always leaves 5 % extra fat: the soap is mild, and a small weighing error does not make a harsh bar.
• Containers only of stainless steel or hard plastic (PP, HDPE). Never aluminium: lye eats it and gives off flammable hydrogen.
• Cold process soap cures for 4–6 weeks before use. The pH of finished soap is 9–10.
• Soap for sale is a cosmetic product (or, in the US, may be a consumer product) with its own rules. Check with the competent authority where you live.

What's inside

Chapters

1. How soap is made
2. Safety: lye
3. Equipment and ingredients
4. Fats and oils: what soap each one makes
5. Calculating a recipe step by step
6. Cold process step by step
7. Hot process and old boiled soap
8. Curing, cutting and storing
9. Additives, scents and laundry soap
10. Common mistakes
11. Printable checklist

Worksheets

• Lye calculator
• Water, scent and cost calculator
• Batch dates
• Batch log
• Soapmaker's calendar
• Labels
• Equipment and safety list