Both are real soap. They differ in how the base is made, what the maker controls, and how the finished bar behaves.

Almost every handmade bar on sale is made one of two ways, and the difference explains most of what you notice in use.

Melt and pour

The maker buys a ready-made soap base, melts it, adds colour and scent, and pours it into moulds. The saponification — the reaction that turns oils into soap — has already happened at the factory. It sets in hours, takes crisp detail, and is the usual route for embeds, layers and transparent bars.

Cold process

The maker combines oils and a lye solution directly, pours the raw batter, and lets saponification finish in the mould over a day or two. The bar is then cured for four to six weeks so the excess water evaporates. Because the recipe is built from scratch, the maker chooses every oil and therefore the hardness, the lather and how the bar feels on skin.

What you notice

• Hardness. A properly cured cold process bar is denser and lasts longer.
• Glycerin. It stays in a cold process bar; many commercial bases have it partly removed.
• Look. Melt and pour gives sharper, more uniform results. Cold process swirls shift from batch to batch — that variation is inherent to the method.
• Ingredients. With cold process the full oil list is knowable, because the maker built it.

Neither is better in the abstract. If you want a specific oil profile and a long-lasting bar, cold process is the reason to pay attention to who made it.