Ingredients

TL;DR: The right choice of ingredients determines the properties of finished soap — hardness, lather, conditioning and longevity. This section covers everything from lye calculation through oil encyclopedia to fragrances and additives.

The right choice of ingredients determines the properties of finished soap: hardness, lather, conditioning, longevity and aroma. This section covers everything from lye calculation through oil encyclopedia, essential and fragrance oils to additives and calculator selection.

Calculators and chemistry

SoapCalc Soap Calculator: a complete guide

The calculator is an absolutely necessary tool - without it, it is impossible to determine exactly how much NaOH to add to the recipe. Detailed Czech annotated guide to the most used free calculator explains all fields - Weight of Oils, Water as % of Oils, Super Fat %, predicted properties (hardness, cleansing, conditioning, bubbly, creamy, INS). Step by step recipe calculation.

Essential reading before your first batch.

Soap calculator comparison

Which app is best for you? Choose from Compare - SoapCalc vs. Brambleberry Lye Calculator vs. SoapMaker 3 vs. mobile app. Comparison table, SAP value verification for key oils, recommendations by manufacturer type.

Saponification chemistry: fatty acids, SAP numbers and pH

A scientific explanation of the process without academic jargon: fatty acids and their effect on soap properties. complete guide covers saponification numbers (table for NaOH and KOH), pH maturation, why soap needs time.

Oils and fats

Oil encyclopedia for soap making

You need to know the SAP numbers and the properties of the oils for a proper recipe. Profiles of 19 oils and fats with SAP numbers for NaOH and KOH can be found in Encyclopedia - from olive and coconut to exotic (argan, tamanu, marula) to tallow and lard. Fatty acid profile, recommended percentage in the recipe, stability and availability in the Czech Republic.

Coconut oil in soap: guide

Coconut oil is the most important ingredient in CP soap and requires an understanding of its properties. Lauric acid and its effect on lathering, dosage (20-30% for standard soap, 100% for salt bar), palm-free alternatives (palm kernel oil) - all in detailed guide.

Fragrances

Essential oils in soap: selection, usage rates, stability

Essential oils add fragrance and can speed up the trace. IFRA limits for the most common EOs, table of trace accelerators (clove, cinnamon, vanillin), citrus EOs and their volatility, phototoxic EOs, combining EOs in compositions - all in EO guides. Where to buy in the Czech Republic.

Fragrance oils in soap: soap safe, flash point, vanillin

The difference EO vs. FO is important for the choice of fragrance. Learn soap safe test, flashpoint, trace acceleration in FO, vanillin browning, documentation for sale (SDS, IFRA certificate, INCI allergens). Soap testing protocol.

Additives and supplements

Soap additives: honey, clays, silk, oatmeal

Ingredients transform soap - adding texture, scent or benefits. Encyclopedia Ingredients with function, dosage and addition technique: honey, oatmeal (colloidal vs. coarse), kaolin, green clay, bentonite, rhassoul, silk fibers, panthenol, vitamin E, ROE, sodium lactate.

How to choose ingredients for your recipe

The basis of every CP soap:

• Oils/fats (100% total) — depends on desired properties
• NaOH (sodium hydroxide) — amount calculated by the calculator
• Water - 33-38% by weight of oils (distilled recommended)

For good lather: min. 20-30 % coconut oil (lauric acid)

For conditioning: olive, shea butter, avocado, castor oil

For hardness: coconut, palm, tallow, stearin

For longevity: Avoid high levels of flaxseed and hemp oil without antioxidants

Frequently asked questions

Do I always need to use a calculator? Yes. Each oil has a different saponification number - without a calculator, you cannot calculate the correct amount of NaOH. The error would lead to either a caustic soap or a soft and non-functional one.

How much coconut oil is too much? Above 40% without a corresponding super fat, the soap starts to dry out. The standard is 25-35% with 5% superfat. The more coconut, the higher superfat you need.

What are the essential oils for a beginner? Coconut (hardness, lather), olive (conditioning), sunflower (conditioning, price), castor (lather, stability). These four form the basis of 80% of the recipes.

Can I use cooking oils from the kitchen? Yes. Food-grade coconut, olive or sunflower oil work in soap just as well as the cosmetic versions. The saponification number is the same.

Where to buy raw materials in the Czech Republic cheap? Coconut and sunflower in supermarkets (DM, Rossmann), olive pomace in Greek shops, the remaining raw materials in e-shops focused on soap making. See Suppliers in the Czech Republic and EU.

What is superfat and why is it important? Superfat (overfatting) is the deliberate addition of less lye than needed - some of the oils remain unsaponified and form a conditioning layer in the soap. The standard is 5%, for coconut soap 8-20%.

See also:

• Recipes for beginners - raw materials in practice
• Dyeing techniques - natural and synthetic dyes
• Suppliers in the Czech Republic and EU - where to buy raw materials