Alkanna

Overview

Alkanna (also called alkanet) is a plant dye extracted from the roots of Alkanna tinctoria, a Mediterranean herb with hairy leaves and small blue flowers. The roots contain alkannin, a naphthoquinone pigment that produces stunning purple-to-red hues when infused into oil. It has been used as a dye since ancient Greece — for textiles, food, wine, and cosmetics.

For DIY formulators, alkanna is a gift: it is one of the few natural colorants that gives you true purple in oil-based products. Most natural dyes lean yellow, orange, or red. Getting a natural violet-purple without synthetic lakes or micas is genuinely difficult, and alkanna fills that gap beautifully. The root pieces or powder are infused into a carrier oil over time, and the resulting deep purple oil is then used in your formulas.

Important distinction: alkanna is oil-soluble only. It will not color water. If you need a water-phase purple, you need a different colorant entirely.

What it does in a formula

Alkanna is purely a colorant. It delivers purple, violet, burgundy, and reddish-plum tones to oil-based products. The exact shade depends on concentration, the carrier oil used for infusion, and the pH of the final product — in alkaline soap, alkanna shifts toward blue-grey; in neutral-to-acidic lip products, it stays true purple-red.

In lip balms and lipsticks, alkanna provides a natural berry-toned tint that looks flattering on most skin tones. In soap, it produces muted lavender to steel-blue depending on your recipe’s superfat and lye concentration. In oil serums, it creates a visually striking purple product that looks luxurious in glass dropper bottles.

How to use

• Oil infusion (cold method): Add 1-2 tablespoons of dried alkanna root to 100ml carrier oil. Let sit in a dark place for 2-4 weeks, shaking occasionally. Strain thoroughly.
• Oil infusion (warm method): Heat carrier oil to 60-70°C with alkanna root for 2-4 hours. Do not overheat — excessive heat darkens the color toward brown. Strain.
• Lip balms: Use 5-20% of your infused oil in the total formula for a soft to medium tint.
• Cold-process soap: Add infused oil as part of your recipe oils (5-15% of total oils). Be aware the color shifts in high pH.
• Oil serums: Use infused oil at 1-5% for a subtle purple hue.
• Best results in neutral-to-slightly-acidic formulas (lip balms, body oils). In soap, expect color shift toward blue-grey.
• Olive oil and castor oil are popular infusion carriers — they pull color well.

Best for / Worst for

Best for: lip balms (natural berry/plum tint), lip glosses, tinted body oils, cold-process soap (muted lavender/grey-blue), oil serums, lotion bars, salves.

Worst for: water-based products (it is not water-soluble), products requiring bright vivid purple (it produces muted, natural-looking tones), products requiring exact color reproducibility batch to batch.

Common pitfalls

Overheating the infusion — Too much heat (above 80°C) degrades the alkannin pigment and pushes the color toward muddy brown instead of vibrant purple. Keep infusion temperatures moderate.

Expecting stability in soap — Alkanna is pH-sensitive. In cold-process soap (pH 9-10), the color shifts from purple toward grey-blue. This can be beautiful, but if you wanted vivid purple in soap, you will be disappointed.

Not straining thoroughly — Root particles left in the oil create gritty spots in lip balms and balms. Strain through multiple layers of cheesecloth or a coffee filter.

Using too little infusion time — A 24-hour infusion produces weak, washed-out color. Give it at least one week (cold method) for decent color extraction. Two to four weeks is ideal.

Assuming the infused oil is shelf-stable forever — The carrier oil can still go rancid. Use the infused oil within the normal shelf life of your carrier oil, and store in a cool dark place.

Substitutes

• Madder Root — produces pink-to-red (not purple) in oil. Similar infusion method but different color range.
• Purple Brazilian Clay — dispersible pigment for soap and scrubs, gives muted purple without infusion.
• Mica (natural) — mineral pigment available in purple shades, far more consistent but not plant-derived.
• Ratanjot (Onosma echioides) — very similar to alkanna in behavior and color, sometimes sold interchangeably.