How to Clean Reusable Straws Without a Pipe Cleaner

The brush is always the first thing to go. It comes in the packet, gets used enthusiastically for a fortnight, and then ends up at the back of a drawer or down the plughole. Meanwhile the straw is still in daily use, getting a rinse under the tap and nothing more.

Here's the uncomfortable bit: rinsing a straw does almost nothing. Water flows down the centre of the tube and barely touches the wall, where a thin biofilm builds up — a slick layer of sugars, proteins and bacteria that you can't see and can't rinse away. That's what you're tasting when a "clean" straw makes water taste stale.

You don't need the brush. You do need one of these five methods.

1. The bicarbonate of soda soak (best all-rounder)

This is the one to reach for first. Bicarb is mildly alkaline, which is exactly what breaks down the fats and proteins holding a biofilm together.

1. Fill a tall glass or jug with hot — not boiling — water.
2. Stir in two tablespoons of bicarbonate of soda and a drop of washing-up liquid.
3. Stand the straws upright in the glass so they fill completely. Tap them to release trapped air bubbles; an air pocket means an unwashed section.
4. Leave for 20–30 minutes.
5. Rinse under a fast-running tap, holding the straw at both ends so water is forced through under pressure rather than trickling.

The pressure rinse at the end matters as much as the soak. A slow trickle won't shift the loosened residue.

2. Denture cleaning tablets (best for stubborn cases)

Slightly unglamorous, extremely effective. Denture tablets are designed to lift protein film and stains from a rigid surface without abrasion — which is precisely the problem you have.

Drop one tablet in a tall glass of warm water, stand the straws in it, and leave overnight. The effervescence does mechanical work along the inner wall that a soak alone can't. Rinse very thoroughly in the morning.

This is the method for a straw you'd otherwise throw away — tea-stained, faintly smelly, or one that's been left in a bag over a weekend.

3. The boiling method (best for a proper reset)

Stainless steel and glass straws only — not silicone, not plastic.

Put the straws in a saucepan, cover with water, bring to the boil and simmer for five minutes. Heat does what scrubbing can't: it denatures the proteins in the biofilm so they lose their grip. Fish them out with tongs, rinse, and stand them upright to dry.

Do this monthly and your straws will genuinely stay fresh. It's also the right response to a straw that's had milk or a protein shake through it.

4. The dishwasher, done properly

Dishwashers get a bad reputation for straws, and it's deserved when people just lay them in the cutlery basket. Laid flat, the inside barely gets touched.

Done properly it works well: stand each straw vertically in the cutlery basket so the spray arm fires directly up the tube, and run a hot cycle. Top rack if your basket is up there. Check your specific product first — stainless steel straws are usually dishwasher safe, silicone is variable, and thin plastic straws often warp.

Even done well, treat this as maintenance rather than deep cleaning. Once a month, use method 1 or 3.

5. Improvised brushes that actually work

If you want the mechanical scrub, you probably already own something that fits a 10mm straw:

• A shoelace or bootlace. The best improvised option by a distance. Soak it in soapy water, thread it through, and pull it back and forth a dozen times. The woven texture scrubs properly.
• A strip of kitchen roll, twisted tight. Twist a corner into a rope, feed it in, and push through with a chopstick or a skewer. Repeat with a fresh piece until it comes out clean.
• A mascara spoolie. Wash it first, obviously. The bristles are close to ideal for a 10mm tube, though the handle limits how far in you can reach.
• A pipe cleaner from a craft set. Not the branded straw brush, but functionally the same thing for about 5p.

Two things that don't work

Rinsing under the tap. Already covered, but worth restating because it's what most people do and believe is sufficient. Water takes the path of least resistance straight down the middle.

Neat vinegar on its own. Vinegar is excellent on limescale and mineral cloudiness. It is not good at protein and fat, which is what a straw biofilm mostly is. Use bicarb for smell and residue, vinegar for scale. If you have both problems, do them as two separate soaks — mixing them in the same glass just neutralises both.

The habit that means you rarely need any of this

Dry the straw standing upright, not lying flat. A straw left flat on a draining board holds a bead of water in the middle by capillary action, and that bead can sit there for days. Damp plus residue plus room temperature is exactly the condition biofilm needs.

Stand them in a glass, ends up, and they'll be genuinely dry within an hour. It's a two-second change that removes most of the problem.

For the deeper explanation of why straws go off, and what the smell actually is, see why does my tumbler straw smell.

When to stop cleaning and replace

Straws are consumables. Replace when:

• A plastic straw is visibly scratched inside — scratches hold odour permanently and no method will fix it.
• Silicone still smells after a boil-safe cleaning method. Silicone is porous and eventually absorbs more than it releases.
• A stainless steel straw has pitting or dark spots, which usually means it's met a chlorine-based cleaner.
• The end has a burr or sharp edge you can feel with a fingertip.

A good stainless steel straw should last years. If yours is going off after months, the material grade is probably the issue rather than your cleaning.

Frequently asked questions

Can I clean a reusable straw with baking soda?

Yes — in the UK it's sold as bicarbonate of soda, and it's the same thing. Two tablespoons in a tall glass of hot water, straws standing upright, 20–30 minutes, then a hard pressure rinse.

How often should I deep clean my straw?

Weekly for water-only use, twice weekly for squash, juice or electrolytes, and immediately after anything milk-based. A daily rinse plus a weekly soak keeps almost any straw fresh.

Can you boil silicone straws?

Most food-grade silicone tolerates boiling, but manufacturers vary and thinner straws can deform. Check the product guidance. The bicarb soak or a denture tablet is the safer default for silicone.

Why does my straw still smell after cleaning?

Usually because it's being stored damp, or because the material has absorbed odour permanently — which happens with scratched plastic and older silicone but not with stainless steel. Try the boiling method once; if the smell survives that, replace it.

Is it safe to use a straw I've only rinsed?

For plain water, occasionally, it's low risk. With sugary or dairy drinks, a rinse-only straw builds biofilm quickly and will taste of it. It's a hygiene and flavour issue more than a serious safety one — but it's easily avoided.

Where can I get a replacement cleaning brush?

Most straw sets include one. Ours do — our stainless steel replacement straws come with a brush and a carry pouch for £7.99. A craft pipe cleaner from any stationers is a perfectly good stopgap.

Start fresh

If your straw has reached the replace-it stage, our stainless steel replacement straws are £7.99, include a cleaning brush and pouch, and fit both Mato London 40oz tumblers and Stanley Cup 40oz — dispatched from the UK.

Browse the full 40oz tumbler range if you're upgrading the cup as well.

Mato London is an independent UK drinkware brand and is not affiliated with or endorsed by Stanley or PMI. Brand names are referenced for compatibility only.