We’ve recently had some technical support calls about losing the lavender scent in soaps, and today I’d like to share some of our thoughts, observations, and results from recent test batches. Come join me for a cup of tea ☕ and let’s chat about soap!
Our recent calls about lavender fading use a lavender that is distilled at home. We are NOT picking on home distillation, we do want to remind folks about the variables in small batch distillation. These variables are; temperature control, varieties of plants, water source, plant maturity at harvest, treatment of plant material between harvest and distillation, and blending/aging after distillation. We encourage everyone to try new things – please document your process to find all the variables between batches.
Many things can cause scents (both fragrances and essentials) to fade in any batch of soap. When we get phone calls from customers like you, we can usually narrow the reason down to one or more of the reasons below.
- If milk is being used as part or all of the liquid, we have noticed that the decomposition of the milk can cause the scents to fade. If you can reduce the milk to 25% of the total liquids used, the scent will not fade.
- Water discounting
- If you use a lower amount of water, the concentrated lye solution can cause the batch to accelerate and/or scents to fade. We recommend using at least 6 ounces of water per pound of fats and when using milk, I prefer 8 ounces total of water and milk per pound of fats.
- Oil Ingredients
- Palm Oil
- If you are using Palm Oil, we recommend making sure it has not fractionated. To prevent issues related to fractionation, we recommend melting your entire received lot of Palm Oil, stirring well and then measuring out what you need. I always recommend melting and dividing into smaller containers if you have a large pail or drum. If you don’t, you can end up with mystery swirls in your soap! Fractionated oils can also cause your scents to become unbalanced and fade.
- Superfat/Excess fat amounts
- Remember to always calculate your lye to leave between 5-8% excess fat that is not saponified. (My favorite excess fat amount is 6 or 7%.) Too much or too little excess fat can cause fading of scents.
- Palm Oil
What if none of these reasons are part of your soaps that have scent fading? We recommend adding 1-5% salt (regular or Kosher salt) to help harden your soap and keep the scent from fading. You can also use 1-3% Sodium Lactate to help the same way.
Don’t forget to check your usage rates with our Fragrance Calculator! You don’t want to use too much fragrance or essential oil because your pocketbook doesn’t need to feel drained and your nose (and your customers) don’t need to deal with instantaneous olfactory fatigue.
Have you experienced scent fading? How have you overcome this? Share your comments below and get a chance to receive a random box of goodies!
Tomorrow I will share physical (not formulation) methods to increase or maintain scents.