Soap dyes (water-soluble, liquid)
Any hue, subtle to bright; dyes tint transparent soap too. Fisher, The Complete Photo Guide to Soap Making primary source, Failor, Making Transparent Soap primary source
Opens the calculator’s starter recipe with this additive in it. No source gives a dose to fill in, so enter your own.
What it is
Soap dyes are water-soluble liquid colours. Some, such as LabColors, contain FD&C colours, which must come from certified batches to colour a cosmetic in the US.
Wholesale Supplies Plus supplier or guide, Soap Queen supplier or guide, 21 CFR 74 and 701.20 primary source
How much
- up to 0.5 tsp per pound of soap Wholesale Supplies Plus supplier or guide
No dose to fill in: enter your own.
When and how
- Usually: at light trace.
- Stir it in as it is.
Wholesale Supplies Plus supplier or guide, Failor, Making Transparent Soap primary source
What it does to the recipe
- It changes neither the lye nor the water: it is only weight in the bar.
Worth knowing
- Caution: Many dyes change colour or fade at the high pH of fresh cold-process soap: test each one first. Wholesale Supplies Plus supplier or guide, Failor, Making Transparent Soap primary source, Fisher, The Complete Photo Guide to Soap Making primary source
- Dyes can bleed into neighbouring layers and swirls, especially in melt and pour. Soap Queen supplier or guide, Fisher, The Complete Photo Guide to Soap Making primary source
- Its colour fades with light and time. Wholesale Supplies Plus supplier or guide
- Caution: Too much can stain skin and washcloths. Failor, Making Transparent Soap primary source
- In US cosmetics, FD&C and D&C dyes must come from batches FDA has certified; a true soap, sold only as soap, is not a cosmetic. In the EU each dye must be in Annex IV of the Cosmetics Regulation. 21 CFR 74 and 701.20 primary source, Regulation (EC) No 1223/2009; 21 CFR 73 primary source
Spoons and drops
- 1 tsp ≈ 6.22 g
- 1 tbsp ≈ 18.6 g
- 1 cup ≈ 298 g
CandleScience supplier or guide
INCI name
CosIng has no single INCI name for it: label it by what it contains.
Guides that discuss it
Sources
David Fisher, The Complete Photo Guide to Soap Making (Creative Publishing International, 2018), p. 20: dyes "give a full range of hues—from subtle to bright and bold", but "can bleed between layers or swirls of soap, especially in melt-and-pour soap. Some are not stable in cold process soap, so test them first"; oxides "are very stable and strong in soap". Natural colours, pp. 82–84. In an infused oil: "Annatto: yellow-orange"; "Alkanet: light to deep purple, depending on the amount used"; "Paprika: orange-peach". In the lye solution: "Indigo: light to deep blue"; "Madder root: pinkish-red"; "Rose clay: deep rose pink". Added to the oils or at trace: "Activated charcoal: light gray to deep black"; "Black walnut hull (ground): speckled brown, also an exfoliant"; "Calendula flower petals (whole or ground): nice, warm yellow"; "Carrots (puréed or juiced): muted orange"; "Cinnamon: reddish tan to brown"; "Cocoa powder: tan to brown"; "Cucumber: pale yellow-green"; "Rosehips (ground): speckled reddish brown"; "Sage: muted green"; "Spirulina: pastel green/blue-green". For "a bright, white bar of soap": "Add titanium dioxide: about 1 teaspoon per 1 pound (454 g) of oils."
Catherine Failor, Making Transparent Soap (Storey, 2000), chapter 6: "Many dyes take a battering from the high initial pH of cold-process soaps and are often altered beyond recognition"; "Because of its neutrality, transparent soap can be tinted in either subtle earth tones or bright primary colors"; "Too much food coloring results in a soap that will stain your hands or washcloth"; "Liquid chlorophyll comes in various shades of green, from a mossy hue to a brighter grass-green".
Wholesale Supplies Plus, soap colorants guide: water-soluble liquid colorants, "a modest amount—less than half a teaspoon per pound of soap—is sufficient"; "In the case of melt-and-pour soap, just a few drops per pound are necessary"; "water-soluble colors can morph in cold process soap, because they often don’t hold up to the higher pH levels"; store "away from direct sunlight to avoid fading".
Soap Queen, non-bleeding colorants: "Bleeding colorants are colorants that can migrate into other layers of your soap"; "some liquid colorants (like LabColors) have FD&C colorants in them and will make your soapy projects bleed".
US 21 CFR 74.2101, for example: "FD&C Blue No. 1 may be safely used for coloring cosmetics generally"; "All batches of FD&C Blue No. 1 shall be certified in accordance with regulations in part 80". 21 CFR 701.20: the Act "specifically excludes soap" from cosmetics, and FDA reads soap as a product "labeled, sold, and represented only as soap".
EU: Regulation (EC) No 1223/2009, Article 14(1)(c), a product may contain as colourants only those in Annex IV. US: 21 CFR Part 73 Subpart C lists the colour additives for cosmetics, and turmeric, paprika and spirulina are listed for food only; under 21 CFR 701.20 a true soap, sold only as soap, is not a cosmetic.
CandleScience, liquid soap dye safety data sheets (Black Vibrant and Ocean Blue, 2021), glycerin-based dyes (INCI: Glycerin, with the colours): "Specific gravity (H2O=1): 1.261".
A water-based dye is lighter than a glycerin-based one.