Soap & Bath Bomb Moulds

Choosing a mould

The mould decides the shape, the finish and how easily the bar comes out. Silicone is the most forgiving. It flexes, so even detailed shapes release cleanly, and it handles heat well. It is the right choice for intricate designs, bath bombs and anything you want to unmould without a fight. PVC is rigid and holds a crisp edge, which suits clean geometric bars and gives a sharper finish than a flexible mould. 3D moulds make shapes with depth rather than a flat back, so the soap looks like an object rather than a bar. Bath bomb moulds press two halves together into a sphere.

Sizing and yield

Work out how much base you need from the mould rather than the other way around. A standard bar is around 100g, so a 1kg block of soap base fills roughly ten cavities of that size. If you are pouring for a market, count cavities per pour and pick a mould that matches your batch size rather than one you have to refill four times.

Unmoulding without breakages

Let the soap set fully and cool right down before you try. Chilling it briefly in the fridge firms it and makes release easier, especially with a rigid mould. Push from the base rather than pulling at the edges, and with silicone peel the mould back off the soap rather than tugging the soap out of the mould. Bath bombs need to dry hard before handling. Wash moulds in warm soapy water and let them dry fully before storing.

Moulds work with every base in melt and pour soap bases, and with candle wax for moulded candles.