Pumice powder
A heavy-duty scrub, for hand soap. Fisher, The Complete Photo Guide to Soap Making primary source
Opens the calculator’s starter recipe, 1000 g of oils, with this additive at the dose it fills in, ready to change.
What it is
Pumice powder is ground pumice, sold in grades; Soap Queen puts it in a mechanic’s soap.
Hess Pumice primary source, Soap Queen supplier or guide
How much
- 1–10 % of the batch (the source does not say of what; taken here as of the batch) filled in Wholesale Supplies Plus supplier or guide
- 2.5 tbsp per pound of oils (from a published recipe) Soap Queen supplier or guide
The calculator fills in 1 % of the batch (the source does not say of what; taken here as of the batch): 14.4 g for the 1000 g of oils in its starter recipe.
When and how
- Usually: at thick trace.
- Also used: at light trace.
- Mix it first with a little of the recipe’s oil, about a teaspoon of powder to a tablespoon of oil, so it spreads without specks.
Soap Queen supplier or guide
What it does to the recipe
- It changes neither the lye nor the water: it is only weight in the bar.
Worth knowing
- In a thin batter it sinks: stir it in once the batter has thickened. Soap Queen supplier or guide
- Sources disagree on whether it speeds trace. Soap Queen supplier or guide, Wholesale Supplies Plus supplier or guide
Spoons and drops
- 1 tsp ≈ 3.8 g (3.15–4.44 g)
- 1 tbsp ≈ 11.4 g (9.46–13.3 g)
- 1 cup ≈ 182 g (151–213 g)
Hess Pumice primary source
INCI name
Pumice
- CAS number
- 1332-09-8
Recipes that use it
Guides that discuss it
Sources
David Fisher, The Complete Photo Guide to Soap Making (Creative Publishing International, 2018), p. 19: exfoliants, "Start with 1 to 2 teaspoons per 1 pound (454 g) of oils or soap base"; calendula petals "retain their yellow color nicely"; coffee grounds, "scrubbiness is determined by the coffee’s grind"; "Citrus peel (dried and ground): offers a medium scrub; add at trace"; cornmeal, "medium scrub; premix with oil and add at trace"; eucalyptus leaves, "a medium scrub, especially if not very finely ground"; lavender buds "will turn brown in cold process soap and look like mouse droppings; gently grind them first to avoid this"; loofah, "light to medium scrub"; mint is "prone to bleeding; steep as a tea first"; oatmeal, "like coffee, the scrubbiness is determined by how ground it is"; poppy seeds, "light to medium scrub"; pumice, "heavy-duty scrub; great for mechanic’s or gardener’s hand soaps"; rose hips, "medium to high scrub; also adds natural color"; rose petals "turn black in cold process soap"; sandalwood powder "gives a medium to high scrub, and makes a lovely purple color"; "ground stone fruit pits (apricots, peaches) and berry seeds (ground or whole) give a medium to high scrub factor"; walnut shells, "a nice medium scrub and a lovely medium brown color".
Soap Queen, mechanic’s soap: 5 tablespoons of pumice for 32 oz of oils, dispersed in oil; "it does cause the soap batter to accelerate".
Wholesale Supplies Plus, pumice powder: "1-10% in soaps".
Soap Queen, exfoliants: fine powders mixed with a tablespoon of lightweight oil or water first; medium and large exfoliants at thin trace.
Hess Pumice Products, technical data sheets (grades 325LHM and 0): loose bulk density 40 lb/ft³ (641 kg/m³) and up to about 900 kg/m³.