In the consumer’s mind, there is an almost automatic association: more foam = more cleanliness. This perception, although intuitive, does not always align with technical reality. In today’s context, where brands are increasingly committed to sustainable, “clean,” or natural products, foam — or its absence — becomes a strategic challenge for formulators, marketers, and product developers.

At Admixtio, we approach this phenomenon from a sensorial, technical, and functional perspective, helping our clients find the balance between naturalness, effectiveness, and perception.

What is foam, and why does it influence so much?

Foam forms when a surfactant (a molecule with one hydrophilic — water-attracting — part and one lipophilic — fat-attracting — part) dissolves in water and is agitated or aerated, for example by rubbing with the hands. When this happens, the surfactant molecules arrange around small air bubbles, forming a stable film around them. This structure reduces the surface tension of the water and allows air to be trapped, giving rise to foam.

The more efficient the surfactant is at stabilizing these bubbles, the more abundant and long-lasting the foam will be. However, this capacity is not directly related to the cleaning power of the product: a formula can produce a lot of foam and clean very little, or the opposite.

Factors such as the type of surfactant, its concentration, pH, temperature, and the presence of salts or lipids also influence the foam’s volume, size, and persistence.

Beyond its technical function, foam has a powerful sensorial and emotional role:

• It indicates that the product is “working”

• Reinforces the idea of hygiene and immediate action

• Contributes to the pleasure of use and cleansing ritual

Sensorial studies have confirmed that consumers perceive foaming products as more effective, even when the foam has no direct link to the actual cleaning capacity. [1], [2]

Natural Body Washes and Shampoos: Less Foam = Less Effective?

One of the main challenges in natural cosmetic formulation is replacing conventional surfactants such as sulfates (SLS, SLES) or ethoxylated compounds (PEGs), known for their high foaming and cleansing power but also for their potential irritation and questionable environmental profile.

Instead, formulators opt for plant-derived, biodegradable surfactants such as alkyl polyglucosides (e.g., decyl glucoside, coco glucoside) or SCI (sodium cocoyl isethionate), which offer a gentler and more skin- and environmentally-friendly profile.

These natural alternatives generate lighter foam, with larger bubbles and less persistence, which can be misinterpreted by consumers as lower efficacy. However, when properly formulated, these cleansing bases perform similarly to classic surfactants in terms of removing grease, dirt, and skin tolerance.

It’s essential to stress that foam volume is not directly related to cleaning efficacy: it is a sensorial phenomenon more than a functional one.

For instance, natural shampoos based on alkyl polyglucosides tend to create less dense foam compared to sulfate-based ones, which may affect the perception of cleanliness unless complemented by a well-crafted sensorial narrative or formulas enriched with emollients and stabilizing agents that enhance the user experience. [3], [4]

Foam in Dishwashing Products

In hand dishwashing detergents, foam also plays a key role in user experience, acting as a sensory indicator of performance. However, from a technical standpoint, foam generation is not directly tied to the product’s degreasing or cleaning power. In fact, in professional settings or automatic dishwashers, excessive foaming is more of a problem than a benefit.

Traditional formulations based on strong anionic surfactants (such as sodium laureth sulfate or linear alkylbenzene sulfonate) produce dense and long-lasting foam, widely accepted by consumers as a sign of cleaning strength. In contrast, eco-friendly or natural products often use non-ionic, plant-based surfactants, such as alkylpolyglucosides (APG) or coconut-derived agents, which have lower foaming ability.

This difference can lead to perceptual dissonance: consumers associate less foam with less effectiveness, which often results in overuse of the product to “compensate” for the lack of visual feedback, even when the formula is effective at removing grease and residue.

Some studies on consumer behavior have demonstrated this overdosing effect when using products with lower foam volume. [5], [6]

In these formulations, it’s crucial to address both the real technical performance and the sensorial and visual language of the product, reinforcing effectiveness through claims or cues beyond foam.

Is Foam only Sensory Marketing?

In part, yes. Foam functions as instant visual feedback. A dish soap with dense foam conveys strength, even if it doesn’t clean better. A foaming shampoo reinforces the self-care experience. But there are also some disadvantages:

• Excess foam makes rinsing more difficult

• Greater potential for irritation

• More residue on skin, dishes, or fabrics

What Can a Brand Do?

• Formulate intelligently: combining gentle surfactants with naturally foaming agents like cocamidopropyl betaine or sugar-derived surfactants (APGs, etc.)

• Educate the consumer: explaining why less foam doesn’t mean less cleaning power

• Enhance sensorial design: include visual or aromatic elements that compensate for the “lack of foam,” such as natural color, fresh scent, post-cleaning feel, or visible dripping

• Use real comparative testing: demonstrate performance (cleaning, softness, rinseability) vs. conventional products, even with lower foam levels

Conclusions

• Foam remains a key perception marker for cleanliness, especially in categories like shampoos, shower gels, and dishwashing liquids

• In natural products, reduced foam is common — but shouldn’t translate to perceived inefficacy

• The challenge lies in creating formulas that perform well, offer a pleasant sensory experience, and communicate clearly and honestly

At Admixtio, we help natural and sustainable brands design balanced formulas, with excellent sensoriality and solid technical claims, even in low-foam contexts.

Want your next natural product to clean effectively — and feel like it? Get in touch.

Bibliography and Web Sources

1. The Role of Foam in Shampoo, Cosmetic Scientist
   https://cosmeticscientist.com/the-role-of-foam-in-shampoo

2. OptimusBio – Foam in Cleaning and Personal Care Products
   https://www.optimusbio.co.za/foam-in-cleaning-and-personal-care-products/

3. A Review on Herbal Shampoo, IRJMETS
   https://www.irjmets.com/upload_newfiles/irjmets71000047629/paper_file/irjmets71000047629.pdf

4. Natural Foaming Agents: A Review, IJCRT
   https://ijcrt.org/papers/IJCRT23A5338.pdf

5. The impact of detergent performance on sustainable consumer laundry behavior, ResearchGate
   https://www.researchgate.net/publication/378833652

6. Consumer Behavior and Fascinating Challenges on Household Laundry and Dishwashing, Tenside Surf. Det. (2016)
   https://www.researchgate.net/publication/310573136