Your laundry locker holds eight bottles. The chief stew before you labelled them by colour, not by chemistry. A guest has just handed you a silk blouse with a foundation mark on the collar, and you are about to reach for the bottle that works brilliantly on the crew mess tablecloths. Understand what is inside the bottle, and you will never make that mistake.
What a detergent actually is
A laundry detergent is a package of four functions. Read the ingredient panel, not the marketing.
| Component | Job | Watch out |
|---|---|---|
| Surfactants | Lift and suspend soil; one end of the molecule grips oil (hydrophobic), the other grips water (hydrophilic) | Anionic = powerful, foamy, hard-water sensitive. Non-ionic = best on oil and grease, low foam. Cationic = softener, poor cleaner. Amphoteric = mild, used in delicate washes |
| Enzymes | Break down specific soils | Protease digests protein — and silk and wool ARE protein. Never on protein fibres |
| Builders | Soften water, hold pH, stop soil redeposition (phosphates, zeolites, citrates, carbonates) | Alkaline builders push pH up — hostile to wool and silk |
| Optical brighteners (OBAs) | Fluoresce blue-white under UV to make whites look whiter | They are a dye, not a cleaner. They build up, yellow over time, and can spot dark garments |
The enzyme table
| Enzyme | Attacks | Use on |
|---|---|---|
| Protease | Protein soils — blood, egg, sweat, milk, grass | Cotton and synthetics only. Never silk or wool |
| Amylase | Starch — sauces, gravy, chocolate, potato | Cotton, linen, synthetics |
| Lipase | Fats and oils — butter, sunscreen, body oil | Cotton and synthetics; needs time and warmth |
| Cellulase | Loose cellulose fibrils (anti-pilling, colour revival) | Cotton — but it slowly thins cotton and destroys viscose over repeated use |
Enzymes work in a narrow window: roughly 30-50 C and near-neutral to mildly alkaline pH. Above about 60 C most are denatured — you are paying for enzymes you have just cooked.
pH: the number that decides everything
| pH | Product | Correct use |
|---|---|---|
| 4-6 (acidic) | Wool/silk wash, sour/neutraliser, rust remover | Protein fibres; final rinse to neutralise alkali residue |
| 7 | Neutral | Delicates, unknown fibres |
| 8-10 | Standard liquid/powder | Cotton, linen, synthetics |
| 11-13 (strongly alkaline) | Heavy-duty degreaser, alkali booster | Deck rags and galley cloths — never guest garments |
Rule: alkali dissolves protein. Every point up the pH scale is a point further from safe for silk and wool.
Onboard Notes
- Decant nothing into unlabelled bottles. Every container keeps its original label and its safety data sheet stays in the laundry file.
- More detergent does not mean cleaner. Overdosing leaves residue that greys fabric, stiffens the hand and irritates guest skin — a very common complaint traced straight back to the laundry.
- Yacht watermaker water is soft, so you need less detergent than the bottle says, not more.
- Build a one-page chemistry card and pin it inside the locker door so a junior stew can never confuse the enzyme detergent with the wool wash.