Soap Making Supplies: what Claude and GPT would buy
Two AI models chose on their own, with no web access. Nobody tested these products: this is what each one says, and how to check it.
They disagree: Claude chooses Essential Depot and GPT chooses Stephenson
In Arts, Crafts & Sewing, Claude and GPT choose the same brand in 46 of 83 categories.
Claude Opus 5.5 · October 27, 2026
Essential Depot (brand)
Pure food-grade sodium hydroxide in a resealable container is the one ingredient every cold-process soap needs, and this brand is a long-standing, consistent source of it.
Not for: Melt-and-pour crafters who never handle lye, and anyone without goggles, gloves and a lye-safe workspace.
GPT 6.1 Sol · November 10, 2026
Stephenson Crystal
A versatile clear melt-and-pour soap base that simplifies crafting and lets you customize colors, scents, and embeds.
Not for: Cold-process soap makers who want to formulate from raw oils.
Claude also lists Stephenson among the brands that matter.
Check before you buy
Where to find Essential Depot
- Essential Depot
Shops seen in search results on November 5, 2026. A shop missing here may sell it too. Nothing was checked by a person.
Brands that matter
- Essential Depot: Widely used food-grade lye in micro-bead form.
- Stephenson: Large maker of melt-and-pour bases.
- Crafter's Choice: Broad soap-making range including bases, molds and fragrance oils.
- Bramble Berry: Long-running soap supplier known for soap-tested fragrances and education.
What to avoid
- Drain cleaners sold as lye, which may contain aluminum or other additives
- Aluminum pots or utensils for lye solutions
- Measuring by volume instead of with a digital scale
Questions
Does handmade soap still contain lye?
No. Properly calculated and cured soap has fully reacted its lye into soap. That is why accurate weighing and a lye calculator matter.