Laundry Science
Choosing a Laundry Detergent: What the Labels Don't Tell You
Most laundry detergent marketing communicates in superlatives — whiter whites, deeper clean, freshness that lasts. Almost none of it tells you anything useful about the chemistry inside the bottle. Understanding the active ingredients gives you a much better basis for choosing a detergent than any marketing claim.
The three main cleaning mechanisms
Laundry detergents work through three main mechanisms: surfactant action, enzyme activity and alkalinity. Standard detergents use all three in combination. Specialist detergents for delicates, wool and silk reduce or eliminate the more aggressive components.
Surfactants are molecules with a water-attracting end and an oil-attracting end. They surround grease and oil particles, making them water-soluble so they can be rinsed away. Every detergent contains surfactants; they're the core cleaning agent.
Enzymes break down specific types of staining at a molecular level. Proteases target protein stains — blood, sweat, dairy. Lipases target fats and oils. Amylases target starch. Enzymatic detergents are significantly more effective on biological stains than non-enzymatic ones. The limitation: enzymes work best in warm water (30–40°C) and are denatured by very hot water or bleach.
pH and fabric safety
Standard detergents are alkaline — typically pH 9 to 11. Alkalinity improves cleaning performance on many stains, but it also attacks certain fibres. Wool and silk are protein-based fibres that are damaged by prolonged exposure to alkaline conditions. This is why specialist wool and silk detergents are pH-neutral or slightly acidic: they clean without degrading the fibre structure.
Fabric softener: what it actually does
Fabric softener deposits a thin coating of cationic surfactants on fibres, which makes them feel softer and reduces static. The trade-off: it reduces moisture absorption in towels and sportswear, and it coats synthetic fibres in a way that traps odour over time. For everyday cotton and synthetics, the benefit is cosmetic. For towels and activewear, it's counterproductive.
Matching detergent to fabric
Cotton and linen: standard detergents work well. Enzymatic detergents improve results on biological staining. Hot wash compatible. Wool and cashmere: use a pH-neutral wool-specific detergent. Standard detergents at any temperature will gradually damage the fibre. Silk: pH-neutral or silk-specific detergent, cool water only. Synthetics: standard detergents are fine; avoid fabric softener for activewear. Dark and coloured items: use detergents formulated for colours, which contain fewer bleaching agents.
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