03/09/2026
✨ Honey in Skincare: The Science Behind “Natural” Preservation ✨
You may have noticed a trend: some natural skincare products, both water-free (like those comprised solely of oils or solid fats such tallow) and water-containing (think lotions, creams, hydrosols) are being made with honey and no added preservative.
Honey is often described as “naturally antimicrobial and antibacterial,” but the reality is a bit more nuanced.
Here’s what the science tells us:
1️⃣ Unopened water-less products are mostly stable
Honey, in and of itself, naturally contains ~17–20% water, but this water is tightly bound, creating a low water activity environment where most microbes cannot grow.
Oils and solid fats themselves contain no water (when properly rendered and stored), so a fresh, sealed honey-and-oil product generally does not support microbial growth.
2️⃣ Once the jar or container is opened, things change
Honey is hygroscopic, meaning it absorbs moisture from the air.
Everyday use can introduce water — from wet fingers, bathroom humidity, or even condensation.
These small changes can create pockets of higher water activity, which are the perfect environment for yeast, mold, or bacteria to grow.
3️⃣ Water-containing products are even trickier
When honey is added to lotions, creams, or other water-containing products (think hydrosols, Castile soap and raw aloe vera) its antimicrobial effect dramatically decreases due to the change in water activity and structural change.
Without a proper preservative system, these formulas can quickly become microbiologically unsafe, even if they feel “natural.”
The takeaway:
Honey is a fascinating, beneficial ingredient — but it is not a guarantee of long-term microbial safety once a product is opened or combined with any water-containing ingredient(s).
Understanding water activity, formulation structure, and real-world use is key to safe skincare formulation.
Side note: This is why the use of fresh plant matter is discouraged when making herbal oil infusions.
Curious to learn more about why “natural” doesn’t automatically mean safe, and how formulators account for it?
🧪 Dive into the science of water activity, honey’s antimicrobial properties, and preservative systems — it’s more complex than most of us realize!
Links to a few articles are provided in the comments to get you started.
