Sclerotium Gum

Overview

Sclerotium gum is a high-molecular-weight polysaccharide produced by fermentation — specifically by the fungus Sclerotium rolfsii growing on a sugar substrate. The fungus secretes long, branched glucose chains that are harvested, purified, and dried into a pale cream powder. Conceptually it is xanthan’s natural cousin: both are fermented polysaccharides, both thicken water-based formulas at low percentages, both are anionic.

What distinguishes sclerotium gum is the skin feel. Where xanthan gum at 0.5% feels slippery and slightly slimy, sclerotium gum at the same percentage feels smooth, soft, and almost cushiony — no stringiness, no slip-and-slide. The molecule’s branching pattern produces a different gel architecture, and that architecture translates directly into a different sensory experience. For face products and high-end gels, sclerotium gum is a noticeable upgrade.

It is also more electrolyte-tolerant than xanthan, shear-stable (does not thin under blending), and stable across an unusually wide pH range. The trade-off is cost — sclerotium gum typically runs 2-3x the price of xanthan per gram.

Sclerotium gum is Ecocert and COSMOS approved, vegan, and broadly considered one of the most elegant natural thickeners on the market.

What it does in a formula

Primary role: thickener for water-based formulas. Gels, serums, mists, toners, hair gels — anywhere xanthan would work but you want a better feel.

Secondary roles: emulsion stabilizer (a tiny 0.1-0.2% in the water phase of a cream improves long-term stability), particle suspender (keeps clays, exfoliants, or pearlescent additives evenly distributed), and a soft film-former that gives styling gels a flexible, non-flaky hold.

How to use

Use it at 0.1-1% of the total formula. Typical ranges:

• 0.1-0.2%: emulsion stabilizer, very light texture boost
• 0.2-0.4%: face serum, light gel
• 0.5-1%: hair gel, thick suspending gel, styling product

Like xanthan, never sprinkle sclerotium gum dry into water — it will clump. Disperse it first in:

1. Glycerin or propanediol: stir into 5-10x its weight of humectant until smooth, then add the slurry to the water phase.
2. Oil: it will not dissolve in oil but it cannot clump in it, so you can pre-mix it into the oil phase before combining with water.
3. Or sprinkle slowly while running a stick blender at low speed.

It hydrates faster than xanthan — usually fully gelled within 15-30 minutes at room temperature. Heating accelerates hydration but is not required. Stable across roughly pH 3-12. For optimum viscosity and stability, disperse above 30°C for at least 30 minutes — the cold-process route works for shelf-stable serums, but the warm dispersion gives a more uniform gel structure.

Sclerotium gum can hydrate in the cold process, which makes it a favorite for formulas where you cannot use heat (vitamin C serums, fragile botanical extracts, mist toners).

Best for / Worst for

Best for: face serums, hyaluronic-style hydrating gels, hair gels with a non-sticky finish, gel-cream emulsion stabilizers, high-end natural formulations, vitamin C and AHA gels (it is cold-process compatible).

Worst for: budget-driven formulas (use xanthan — same broad function, cheaper), formulas needing crystal-clear gels (use HEC or a carbomer — sclerotium gum is slightly cloudy), and ultra-stringy industrial-look gels (the smooth feel is the whole point).

Common pitfalls

The biggest pitfall is paying premium prices for sclerotium gum when xanthan would be fine. For thick suspending gels or hair styling products where the slight slimy feel of xanthan does not matter, sclerotium gum is overkill.

Second pitfall: clumping. Like all gums, dump it dry into water and you get fish eyes. Always pre-disperse.

Third: expecting crystal clarity. Sclerotium gum produces translucent, slightly cloudy gels — beautiful but not water-clear. For truly transparent gels use HEC or carbomer.

Fourth: using it at xanthan concentrations and expecting xanthan thickness. Sclerotium gum thickens slightly less per gram than standard xanthan. You may need to go up about 20-30% to match viscosity.

Substitutes

• Xanthan Gum (Clear / Soft grade) — cheaper, slightly less smooth feel, similar gel structure.
• Hydroxyethylcellulose (HEC) — fully clear gels, very different (more synthetic-feeling) skin feel.
• Sepimax ZEN (Polyacrylate Crosspolymer-6) — synthetic, crystal clear, very modern feel.
• Konjac Gum / Cellulose Gum — less common, food-grade options with different rheology.
• Acacia / Gum Arabic — gentler thickening, much weaker, useful for special textures.