Glossary
Gel phase
A heating stage inside curing soap that can deepen colors, which some makers encourage and others avoid.
Gel phase is a period, usually within the first day, when a freshly poured batch of cold process soap heats up from the inside as saponification proceeds, turning translucent and gel-like in the center before cooling and returning to an opaque, solid appearance. It is a normal part of many cold process batches.
Going through gel phase tends to deepen and brighten colorants and can make the bar look glossier, so some makers insulate the mold with towels or a box to encourage full, even gel. Others prevent it entirely, often by refrigerating the mold, because they prefer more muted colors or are using additives that behave unpredictably at higher heat.
A partial gel, where only the center of the loaf gels and the edges do not, is a common outcome rather than a flaw, and it produces a visible ring pattern when the loaf is cut. Overheating a batch, particularly one with a lot of sugar-based additives like milk or honey, can instead cause cracking or a volcano-like overflow.