Rose petals (dried)

Bramble Berry, dried lavender, calendula and red rose petals: "Sprinkle on top of soap or mix the flowers into scrubs or bath salts. To infuse, heat the flowers and the oil of your choice in a slow cooker for 1 to 4 hours or place in an airtight container and leave at room temperature for 4 to 6 weeks. A general usage rate is about 1 tablespoon per pound of oil."

Casey Makela, Making Natural Milk Soap (Storey, 1999; from Milk-Based Soaps, 1997): "Herbs will not keep their original color; most fade in reaction to the lye"; "½ cup (118 ml)" of cornmeal, "½ cup" of raw almonds blended "to a medium-coarse powder", ¾ cup of dried lavender flowers or rose petals, and "½ cup (118 ml) rolled oats" blended "to a medium-coarse powder", per batch of about 85 oz (2410 g) of oils, added "to the liquid when it’s blended for the first time"; "1 ounce (28.4 g) borax" in every recipe, added to the oils with the sugar and glycerin as the lye-milk goes in; soap "light brown if you use cinnamon and cloves".

David Fisher, The Complete Photo Guide to Soap Making (Creative Publishing International, 2018): rebatched soaps, "1 tablespoon (6 g) red sandalwood powder" for 1 lb (454 g) of grated soap, and "1 tablespoon (1.5 g) lightly crushed rose petals buds" for a pound (p. 34); "1 to 2 tablespoons (5 to 10 g) ground walnut shells" in one third of 28 oz (794 g) of grated soap (p. 32); "1 tablespoon (9 g) kaolin, bentonite, or French green clay" in another third and "1 teaspoon activated charcoal—a little goes a long way" in the last (p. 32); "2 tablespoons (10 g) lightly ground oatmeal" for 1 lb (454 g) of grated soap (p. 32); in melt and pour, "¼ teaspoon cosmetic glitter" in about 4 ounces (112 g) of clear base (p. 54); in cold process, "2 teaspoons activated charcoal per 1 lb (454 g) of soap oils" (p. 121), and for the three colours of a clay swirl "½ teaspoon rhassoul clay", "½ teaspoon green sea clay" and "½ teaspoon red Moroccan clay", each mixed with 3 tablespoons (45 ml) of distilled water (pp. 121–122).

David Fisher, The Complete Photo Guide to Soap Making (Creative Publishing International, 2018), p. 86: "most all flower petals, except calendula, will turn black when they come into contact with lye"; "Herbs such as rosemary, leaves such as eucalyptus and patchouli, citrus peels, ground rose hips, and teas such as spearmint and peppermint, can all be used to make beautiful soaps. But, like flower petals, they turn brown or black. Most dried leaves, especially rosemary and eucalyptus, need to be ground finely or they can be too scratchy".

Lovely Greens, herbs and dried flowers in soap: "I tend to use 1-3 tsp of plant material per pound (454 g) of soap. One teaspoon for dense material, like poppy seeds, and three teaspoons for fluffier herbs, like calendula petals"; "Calendula flower petals don’t discolor in soap recipes"; "rose petals will turn rusty brown wherever they touch soap, and almost every herb turns dark brown when mixed in"; lavender, "Inside the soap, the buds turn brown"; "most fruit and vegetable juices or purees will turn your soap brown or fade to an unexciting tan or yellow"; "Botanicals can soften, mold, and rot if kept in moist or humid places"; "Too many dried seeds or herbs stirred in can feel scratchy or stop the soap from lathering properly".

Wholesale Supplies Plus, dried lavender, calendula, chamomile, rose, sage and eucalyptus: "Note: Some herbs and botanicals will brown overtime when exposed to hot liquids and high pH." On lavender buds: they "have a tendency to turn brown when mixed into soap of any kind. We have found that they are best used as decoration on the tops of a soap loaf."

Voyageur Soap & Candle, botanical product pages, "Approx. Cups/ Lb": lavender flowers 17; calendula petals 44; chamomile flowers, whole, 21; red and pink rose petals and buds 22; peppermint leaf, cut and sifted, 15; eucalyptus leaf, cut and sifted, 7; sage, ground, 8; kelp powder (Ascophyllum nodosum) 3; black walnut hulls powder 4. Peppermint and eucalyptus leaves "can be sprinkled into the soap mixture when at a light trace to create a speckled effect"; comfrey leaf goes "into the lye water to create even color distribution which produces a natural green bar, or sprinkle it into the soap mixture when at a light trace". Density = 453.6 g ÷ (cups × 236.6 mL).