Expert shares why your water bottle still smells even after washing - and how to stop it

Expert shares why your water bottle still smells even after washing - and how to stop it Sometimes no matter how many times a water bottle is washed it has an unpleasant smell Thousands of people have turned to reusable water bottles which can help both save money and the planet. But one common problem is that at times, despite washing carefully, the bottle can be left with an unpleasant smell that is hard to clear. According to Google Trends, the term ‘water bottle smells’ has received a 9,900% uplift in the past month, proving that much of the UK is experiencing the same water bottle dilemma. Now an expert has shared the reason for the smell - and the best way to get rid of it so it doesn't impact its use. Sports Performance Analyst Josh Felber at FLBR says the problem is often caused by a build-up of bacteria. Testing by WaterFilterGuru discovered an average of 20.8 million colony-forming units (CFUs) of bacteria on the reusable bottles sampled, with spout-top and screw-top lids recording 30 million CFUs each. He explained: "Ultimately, a water bottle will smell, even after washing, due to a buildup of bacteria If the smell is persistent, remove the silicone seal that is underneath the lid. "Many people unscrew the lid and wash it as one piece, assuming that the task is then done. However, on bottles with a removable sealing ring, this method sees bacteria build up underneath the lid that remains unwashed.’ Wash underneath the seal, not just around it Josh said: "Where removal is advised, clean the ring and the channel it sits in independently. Use warm water, washing-up liquid and an appropriate brush where the manufacturer advises, then wash thoroughly. "Cleaning the ring without cleansing its groove leaves part of the job incomplete. Pay attention to the underside of the seal and the recessed edges that are challenging to reach while it remains fitted." But he warned: "Do not force out any of the bottle's fixtures or use utensils such as a knife to pry the seal loose. Expanding or damaging it could mean that the bottle is no longer airtight." A clean bottle might still be laden with bacteria "A gleaming interior doesn’t mean the bottle is clean, " warned Josh. "Design-dependent, the lid may feature a removable straw, mouthpiece or bite valve. These must be cleaned to ensure that bacteria doesn’t transfer onto the mouth or cause a foul odour. "If you use your bottle for protein shakes, smoothies or flavoured drinks, check every surface the drink passes through rather than concentrating only on the main chamber." A common misconception One common misconception is that a water bottle's lid can be immediately replaced post-wash, as theoretically, it will only get wet again when water is dispensed back into the bottle. However, this isn’t the case; once all parts of the bottle are clean, resist immediately reassembling the lid. Ensure our latest lifestyle news always appears at the top of your Google Search by making us a Preferred Source. Click here to activate or add us as Preferred Source in your Google search settings Josh advised: "Refitting the lid straight back on a freshly washed bottle can trap bacteria and mould, which both fuel the growth of bacteria. Although washing eliminates dirt and most microbes, it doesn’t sterilise the bottle. "Any remaining microorganisms are likely to grow where moisture and traces of residue persist, particularly around seals and inside lid mechanisms. That dampness can contribute to the stale or musty smell you notice when you next unscrew the lid. "After washing, leave the bottle, lid, seal and any other removable components separate until completely dry, following the manufacturer’s instructions. Drying helps limit microbial growth between uses; it does not replace thorough cleaning. "For your next wash, remember one straightforward rule: if the lid seal is designed to come out, remove it before cleaning, and wash underneath it."