Rosemary extract (ROE)
Sold to hold off rancidity and orange spots.
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
Rosemary extract, sold as ROE, is graded by its carnosic acid: 2 %, 5 % or about 7 %. The same INCI name also covers extracts made with glycerin or water, so check which one a supplier sells.
Supplier data supplier or guide, Givaudan (Naturex) primary source
How much
- 0.1 % of the oils in a controlled test filled in Dunn, “The Dreaded Orange Spot” primary source
- 0.02–0.08 % of the oils Soap Making Resource supplier or guide
- up to 0.05 % of the oils Classic Bells supplier or guide
- 4–8 drops per pound of soap MakeYourOwn supplier or guide
- up to 3 % of the batch in rinse-off products, the highest reported use: not a recommendation CIR primary source
The calculator fills in 0.1 % of the oils: 1 g for the 1000 g of oils in its starter recipe.
When and how
- Usually: into the oils.
- Stir it in as it is.
Classic Bells supplier or guide
What it does to the recipe
- It changes neither the lye nor the water: it is only weight in the bar.
Dunn, “The Dreaded Orange Spot” primary source
Worth knowing
- In Dunn’s test, at 0.1 % of the oils, it held off rancidity longest: beyond 300 hours. Dunn, “The Dreaded Orange Spot” primary source
- Caution: More is not better: in soybean oil it worked best at 0.02–0.05 % and sped rancidity up at 0.01 % and at 0.5 %. Hall & Cuppett (1993) primary source
- Extracts differ in strength, sold at 2, 5 or about 7 % carnosic acid, and the same name also covers glycerin and water extracts. Supplier data supplier or guide
Spoons and drops
- 1 tsp ≈ 4.64 g (4.59–4.69 g)
- 1 tbsp ≈ 13.9 g (13.8–14.1 g)
- 1 cup ≈ 223 g (221–225 g)
- 1 drop ≈ 26.5 mg (20–33 mg): droppers differ
Givaudan (Naturex) primary source, Österreichisches Arzneibuch primary source, Aroma-Zone supplier or guide
INCI name
Rosmarinus Officinalis Leaf Extract
- CAS number
- 84604-14-8
- EC number
- 283-291-9
Recipes that use it
Guides that discuss it
Sources
Kevin M. Dunn, "The Dreaded Orange Spot", The Handcrafted Soapmaker (Winter 2005/06): additives at 0.1 % of the oil weight in olive-oil soap held at 60 °C. Rosemary extract and EDTA "lengthened the induction period beyond 300 hours", BHT to 150; grapefruit seed extract, vitamin C, vitamin E and sodium citrate were "virtually identical" to plain olive-oil soap; BHT with sodium citrate did best, and "ROE + Sodium Citrate actually performed worse than ROE alone".
Classic Bells, rosemary extract: up to 0.05 % of the fats, added while the oils are fresh.
Soap Making Resource, rosemary oleoresin: 0.02–0.08 % of the oils.
MakeYourOwn (archived), rosemary oleoresin: "4 to 8 drops per pound of soap, or .02 to .08%".
Cosmetic Ingredient Review, Rosmarinus officinalis ingredients (2014): up to 3 % in bath soaps and detergents.
The highest concentration reported to CIR in industry surveys: what has been used, not a recommendation.
C. A. Hall and S. L. Cuppett, J. Am. Oil Chem. Soc. 70 (1993) 477: rosemary extract in soybean oil worked best at 0.02–0.05 % and was pro-oxidant at 0.01 % and 0.5 %.
Rosemary extracts are sold at 2 %, 5 % and about 7 % carnosic acid; CIR lists 14 % and 25 % diterpene phenols; the same INCI name also covers glycerin and water extracts.
Givaudan (Naturex), StabilEnhance OSR 4 rosemary extract: specific gravity 0.932–0.952 at 20/4 °C.
Österreichisches Arzneibuch (ÖAB), drop table for the Ph. Eur. standard dropper at 20 °C (2024 draft, BASG): refined olive oil 22 mg a drop, sunflower and castor oil 24 mg, lactic acid 29 mg, glycerol 42–43 mg.
Aroma-Zone technical sheets, bottle dropper: CO₂ rosemary extract "1ml = 0.98g = 30 gouttes"; natural vitamin E 32 drops per mL; lactic acid about 36 drops per mL.