What Detergent Should You Use on Silk?

Use a pH-neutral or silk-specific detergent — a small amount, in cool water. A dedicated silk or delicates wash is ideal; a gentle wool detergent works too, and in a pinch a few drops of a mild, fragrance-free soap will do. What you must keep away from silk is anything harsh: "bio" or enzyme detergents, bleach, fabric softener and optical brighteners all quietly damage the fibre. Silk is a protein, not a plant, so it wants a gentle, near-neutral cleaner — not the powder built to strip grease off cotton.

Here's exactly what to reach for, what to avoid, and the honest answers on the products people always ask about.

So what detergent should you use on silk?

The short list is reassuringly simple. A silk- or wool-specific detergent is the safest choice, because these are formulated pH-neutral and enzyme-free for exactly this kind of fibre. A general delicates detergent is the next best thing, as long as it's gentle and not a "bio" formula. And if you've nothing dedicated to hand, a tiny amount of mild, pH-neutral soap — a fragrance-free baby shampoo or a plain gentle hand soap — will clean silk safely for one wash. The common thread is gentleness and a neutral pH; the amount matters too, since silk needs only a capful, never a scoop.

Why ordinary laundry detergent damages silk

It comes down to chemistry. Silk is made of fibroin, a protein built from amino-acid chains — closer to your own hair than to cotton. Most everyday detergents are alkaline (high-pH) and many are "biological", meaning they contain enzymes designed to break down protein and fat stains. On a cotton shirt that's exactly what you want; on silk, those same enzymes and that high pH go to work on the fibre itself, dulling the sheen and weakening the threads over time. Textile conservators wash protein fibres in cool, near-neutral solutions for precisely this reason. A gentle pH-neutral detergent cleans the silk without dismantling it.

What to keep away from silk

A short avoid-list saves a lot of ruined silk:

• "Bio" / enzyme detergents — the enzymes digest protein, which is what silk is.
• Bleach (chlorine or oxygen) — far too harsh; it eats the fibre and the colour.
• Fabric softener — it coats the filaments and kills the natural sheen.
• Optical brighteners / "whitening" detergents — they alter the colour and can yellow silk over time.
• Hot water — even the right detergent won't save silk from heat; keep it cool, below 30°C.

"Can I use…?" — the quick answers

The products people most often ask about:

• Wool wash (e.g. a gentle wool detergent): yes — wool is also a protein fibre, so these are a good, easy match.
• Baby shampoo or mild hand soap: yes, in a pinch — a few drops, well diluted, fragrance-free.
• Dish soap: only sparingly and rarely — some are surprisingly harsh; a tiny amount of the mildest kind, well rinsed.
• White vinegar: a small splash in the rinse can help lift residue and soften, but don't overdo it.
• Regular powder or "bio" liquid: no — this is the main thing to avoid.

How much to use, and how to wash

Less than you think — a capful of gentle detergent in cool water is plenty, whether you're hand-washing or running a cold delicate cycle with the pillowcase zipped into a mesh bag. Swirl rather than scrub, rinse until the water runs clear, press (never wring) the water out, and dry flat away from heat and direct sun. The full routine, including the difference between hand and machine washing, is in our silk pillowcase care guide — and if you'd rather use the machine, here's whether you can machine wash silk and how.

If you'd like silk that rewards this kind of gentle care, our LS Silk AU mulberry silk pillowcases are 22-momme, 100% mulberry silk and OEKO-TEX certified — made to keep their sheen for years when washed kindly.

The rule, in a sentence: match the cleaner to the fibre. Silk is a protein, so it asks for a gentle, neutral wash and a light hand — give it that, and the right detergent becomes the easiest part of keeping silk beautiful.