How to Clean Silicone Straws Naturally (Without the Soapy Taste)

Reusable straws are one of the easiest swaps away from single-use plastic — but they only stay that way if you can actually keep them clean. The inside of a straw is the one spot you can't see and can't reach with a normal sponge, which is exactly why straws end up cloudy, smelling faintly off, or carrying a soapy taste that won't rinse away.

Here's how to clean every kind of reusable straw properly — silicone, rubber, glass and curly — including the parts most guides skip: getting the soap taste out, what to do without a straw brush, and whether boiling is actually a good idea.

Why straws get gross (and why the inside matters most)

Whatever goes through a straw leaves a thin film behind — milk, smoothies, juice and cordial are the worst offenders because the sugars and fats cling to the inner wall. Rinse a straw under the tap and the water runs straight through the middle without touching the sides, so it looks clean while a film quietly builds up. Left in a damp straw, that film is where smells and mould start. The fix is simple: clean the inside of the straw every time, and let it dry fully before you put it away.

What you need

• A straw cleaning brush sized to your straw — a nylon-wire straw cleaning brush is the everyday workhorse (Kaally's comes in 6mm for the KaakaaBaby straw and 8mm for the adult bottles).
• Warm water and a little mild dish soap.
• For deep cleans: bicarb soda (baking soda), white vinegar, or a slice of lemon.
• A spot to air-dry straws upright.

How to clean a silicone straw (the everyday method)

1. Rinse straight after use — don't let milk or smoothie sit and dry inside.
2. Push a wet, soapy straw brush all the way through, two or three passes. This is the step that actually cleans a straw.
3. If your straw has an anti-spill valve (most kids' bottle straws do), gently work the brush through the valve end — that flap traps liquid and is the first place residue hides.
4. Rinse until the water runs clear and you can't feel any slip of soap inside.
5. Dry upright so water drains out rather than pooling in the middle.

Silicone straws are also top-rack dishwasher safe — but the dishwasher alone won't always clear the inner film or the valve, so give it a quick brush as well.

How to get the soap taste out of a silicone straw

Silicone is slightly porous, so it can hold onto the taste of strong dish soap (and, when brand new, a faint factory smell). If your straw tastes like soap no matter how well you rinse:

• Switch to a small amount of mild, fragrance-free dish soap — perfumed or concentrated soaps are the usual culprit.
• Soak in bicarb — a teaspoon of bicarb soda in a cup of warm water for 20–30 minutes neutralises soap and smells. Brush through, then rinse.
• Or soak in diluted white vinegar (one part vinegar to two parts water) for 15 minutes, then rinse well.
• Boil to reset a new straw (see below) to clear the out-of-the-box silicone smell.

A squeeze of lemon in warm water works as a gentler, nicer-smelling version of the vinegar soak.

How to clean a straw without a straw brush

• Soak first, then flush hard — warm soapy water for 10 minutes loosens the film, then run the straw under a fast tap.
• Bicarb or vinegar soak — chemistry does some of the scrubbing for you.
• A clean cotton string threaded through and pulled back and forth works in a pinch.
• Dishwasher top rack for silicone, glass and stainless straws (not rubber).

These work for a light clean, but for anything milky or for a valve straw, a proper straw brush is worth it.

Can you boil silicone straws?

Yes. Food-grade silicone is heat-resistant, so a 3–5 minute boil is a safe, chemical-free deep clean — ideal for resetting a new straw's smell or sanitising after illness. Drop the straw into boiling water, let it go a few minutes, then lift out with tongs and cool. You can also use a steam or UV steriliser. One tip: boiling cleans but doesn't scrub — for a milky straw, brush it first, then boil.

How to clean rubber straws

Genuine rubber (and soft "rubbery" straws) is more porous and less heat-tolerant than food-grade silicone, so treat it more gently:

• Brush and hand-wash in warm, mild soapy water.
• Skip the boil and the dishwasher unless the maker says it's safe; high heat can degrade rubber.
• Soak in bicarb to lift smells rather than reaching for heat.
• If a rubber straw stays smelly or discoloured after a good clean, replace it.

Worth knowing: many straws sold as "rubber" are actually food-grade silicone — the more durable, heat-safe, taste-neutral choice.

How to clean glass straws

• Brush through with a straw brush and warm soapy water, or use the dishwasher top rack.
• They're boil- and steriliser-safe.
• Check the ends for chips before each use — that's the one weak point of glass.

How to clean curly or spiral straws

• Soak first in warm soapy water (or a bicarb soak) to loosen everything.
• Flush under pressure — hold the straw firmly over a running tap so water is forced through the spiral.
• A flexible nylon-wire straw brush will follow gentle curves where a rigid one won't.
• Dishwasher top rack for silicone and glass curly straws.

How often should you replace a reusable straw?

Replace a straw if you notice discolouration or cloudiness that won't wash out, thinning or splitting, a smell or taste that survives a deep clean, or — for kids' valve straws — a change in how easily liquid flows. As a rule of thumb, swap a well-used everyday straw every 3–6 months, sooner for a baby or toddler bottle straw that sees milk and formula daily.

Quick reference

Frequently asked questions

Why does my silicone straw taste like soap?

Silicone is slightly porous and holds onto strong or perfumed dish soap. Use a small amount of fragrance-free soap, rinse thoroughly, and soak in bicarb or diluted vinegar to reset it.

Can you put silicone straws in the dishwasher?

Yes — top rack. Give the inside a quick brush as well, as the dishwasher doesn't always clear the inner film or a valve.

How do I clean the valve on a kids' bottle straw?

Work a wet straw brush gently through the valve end and flush with water. Milk and formula residue collects there, so do it every wash.

What's the best brush for cleaning straws?

A nylon-wire straw brush sized to your straw. Kaally's straw cleaning brush comes in 6mm (KaakaaBaby) and 8mm (adult bottle) sizes.

Keep it clean, keep it longer. Every Kaally glass bottle and the KaakaaBaby bottle comes fully apart — straw, sleeve and lid all separate — so there's nowhere for residue to hide.