Nettle leaf, powdered

Lovely Greens, natural soap colorants: cinnamon, "use up to 1 tsp ground cinnamon powder PPO. Be aware that cinnamon leaves a slightly gritty feeling"; beetroot, "Warm to dull brown", "Unfortunately, beets do not color CP/HP soap red"; black walnut hull powder, "Add powder at trace and be aware that they create a scratchy or exfoliating texture"; red sandalwood, "Add 1/4-1/2 tsp powder PPO at trace after premixing in a little oil. Can be very scratchy if you use more than this"; woad, "Add 1-2 tsp powder PPO to the lye solution"; rose hips, "Up to 1 tsp ground rosehip powder PPO"; nettle leaf, "muted green", "Premix dried and powdered nettle leaf with a little water and add at trace. Use 1-3 tsp PPO"; kelp, "Dark green", "at trace at up to 3 tsp PPO. Pre-mix in an equal amount of distilled water"; sage, "muted green that fades with time", or "1 tsp PPO dried sage at trace for dark speckles"; peppermint, "1 tsp PPO finely ground peppermint leaves at trace"; liquid chlorophyll, "stunning greens from using about 1 TBSP PPO", fading "into a greeny-yellow"; cucumber, "initially green but usually fades to a muted yellow"; chamomile, "Infuse flowers in distilled water and use the strained liquid to make the lye solution"; green tea, "Brown-green"; rhassoul clay, "Brown"; French green clay, "pale pastel green to earthy green"; "plant-based greens tend to be fugitive". PPO is per pound of oils.

Elizabeth Letcavage and Melissa Harden, Natural Soap Making (Stackpole Books, 2013): calendula "is the only flower that will keep its yellow color through the saponification process. Other flowers ... will turn brown or black"; "Lavender flowers will have a nicer appearance in soap if they are slightly ground"; light additives "(such as seeds, grains, or lavender flower buds)" are added at "heavy trace" to stay suspended; "Leaves of herbs such as mint, nettle leaf, and lemon balm are dried before use"; "Ground Nettle Leaf 2–3 teaspoons", "Ground Oats ¼ cup" and "Ground Cornmeal ¼ cup" in recipes of 48 oz of oils, added at light trace; the Basic Three-Oil Soap, 48 oz of oils, takes "½ cup ground oats or other additive".

The Nerdy Farm Wife, nettle and horsetail shampoo bars: the olive oil "infused with stinging nettle & horsetail, if possible"; "Place the saucepan over a low burner and heat gently for about 1 1/2 hours, or until the herbs are infused into the oils to your satisfaction"; "Strain the oils into a new container, pressing firmly with the back of a spoon to make sure you get most of the oil from the herbs."

Anne-Marie Faiola, Pure Soapmaking (Storey Publishing, 2016), chapter 5, "Herbal and Other Additives for Soap", each at "2 tsp powder per pound of soap": olive leaf powder, "Yellow/green", "Will fade with exposure to light"; comfrey powder, "Light green", "Gel phase enhances the color. Will fade substantially with exposure to light"; nettle leaf powder, "Green"; spirulina powder, "Deep green", "Color is enhanced by a hot gel phase, but will fade substantially with exposure to light"; indigo powder, "Blue/gray", "added as a dispersed powder ... or added directly to hot lye-water before combining oils"; alkanet root powder, "Purple/gray", "Infusion will fade over time; dispersed powder is more color stable"; paprika, "Red/orange", "Gives a speckled appearance"; rose clay, "Rosy pink", "Disperse in distilled water instead of oil"; madder root powder, "Dark red"; yarrow powder, "Yellow/tan", "Dispersed powder can be added at trace, or the dry powder can be infused into lye-water to create a more yellow hue"; cocoa powder, "Rich brown", "Gel phase enhances the color, as does exposure to air". For the chart’s soaps "all powdered additives were dispersed at a ratio of 1 part powder: 3 parts oil"; "The colorants were added at trace and went through gel phase." Oil infusions: "most soapers use at least 2 tablespoons of herb for every 4 ounces of oil. I prefer to use a tablespoon of herb for every ounce." Clay in the water before the lye: "The heat reaction from the lye-water will produce a deeper color than will adding the clay at thin trace".

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.

Nettle leaf powder by volume: "approximate cups to one pound: 5", 0.383 g/mL (Monterey Bay Herb Company, conventional and organic); 7 cups in a 1 lb bag, 0.274 g/mL (Frontier Co-op); a loose bulk density of 0.41 g/cm³ for air-dried leaves milled through a 0.5 mm sieve (Foods 10(6):1152, 2021, doi:10.3390/foods10061152, table 1). Density = 453.6 g ÷ (cups × 236.6 mL).