The Preservative Masterclass

The Preservative Masterclass is a 29-page digital workshop developed by The Skin Science Company — Australia's trusted B2B cosmetic raw materials supplier. It is written specifically for DIY skincare makers and beginner formulators who want to create products that are genuinely safe, stable, and shelf-ready.

Without correct preservation, any water-containing cosmetic product can become contaminated with bacteria, yeast, or mould within days of manufacture. This guide gives you the exact knowledge to prevent that — with worked calculations, reference tables, and printable worksheets included.

What You Will Learn

• Chapter 1 — Why Preserve? — Understand what microbial contamination actually looks like, why water activity is the real risk factor, and why 'natural' does not mean safe without preservation.
• Chapter 2 — The Science of Preservation — Learn how pH windows and input ranges determine whether your preservative works at all. Includes a worked calculation showing exactly how to weigh your preservative into a 200g formula.
• Chapter 3 — Natural, Synthetic and COSMOS — Understand the difference between natural, nature-identical, and synthetic preservatives. Learn what COSMOS certification actually means and how to choose a preservative that aligns with your brand philosophy.
• Chapter 4 — The Master Preservative Reference Table — A complete reference covering 14 of the most widely used cosmetic preservatives, including INCI names, pH ranges, input percentages, heat stability, COSMOS status, and compatibility warnings.
• Chapter 5 — Swapping Preservatives Safely — A 3-step process for substituting one preservative for another without compromising your formula. Includes a Quick Selection Guide organised by product type and pH.
• Chapter 6 — Knowledge Check — Six scenario-based quiz questions with full answer explanations to consolidate your learning before you formulate.
• Beginner's Glossary — 16 key terms defined clearly — from Aw (water activity) to pH, INCI, broad-spectrum coverage, and challenge testing.
• Formula Worksheet + pH Adjustment Log — Printable reference pages to record your preservative choices, input percentages, heat addition method, and pH adjustments for every formula you make.

Product Details

Who Is This For?

This guide is for you if you are new to cosmetic formulation and want to understand preservation properly from the start, if you make lotions, creams, serums, toners, or any water-containing product, if you have been guessing at preservative amounts and want to formulate with confidence, or if you want to understand the difference between COSMOS-approved and conventional preservatives before choosing one for your brand.

Frequently Asked Questions