We're not the only bottle brand.
But we have the answers.

Fluye is a double-walled, vacuum-insulated stainless steel thermal bottle. It keeps drinks cold for 24 hours and hot for 12 hours. BPA-free. With a lifetime warranty. And for every unit sold, 5.4 liters of drinking water per month are funded for communities in Peru.

In shorter words: it's a bottle of real quality with a real purpose behind it. We're not the only bottle brand. But we are one of the few that shows you the numbers, even if they are small.

18/8 is the composition of the steel: 18% chromium and 8% nickel. Chromium forms an invisible oxide layer that protects the metal from oxidation. Nickel adds strength and shine.

This alloy corresponds to 304 grade stainless steel, the standard in kitchen utensils and food equipment. It does not release heavy metals, does not transfer flavors, and withstands years of daily use without degrading.

Yes, completely. BPA (Bisphenol A) is a compound found in some polycarbonate plastics. Not in stainless steel. Steel does not need internal coatings that could contain it.

When a brand of steel bottles heavily emphasizes "BPA-free," it's stating something true, but it's a default characteristic of any steel bottle. It's not a differentiator; it's the minimum expected. What truly makes a difference is the quality of the alloy and the finishes.

Between the two steel walls is a vacuum, literally an absence of air. Heat is transferred in three ways: conduction, convection, and radiation. The vacuum eliminates the first two almost completely. The third (radiation) is minimized by the polished interior finish.

The result: the liquid inside remains at its original temperature for hours, with no outside heat entering or inside heat escaping.

There are concrete signs that don't lie:

• Specify the steel grade: 18/8 (304) or 18/10 (316). Without this information, there's no guarantee of the alloy.
• Verifiable double-wall vacuum insulation: fill with cold water. If there's no external condensation after a few minutes, the vacuum is intact.
• No metallic odor or taste: a quality bottle doesn't transfer anything to the liquid.
• Real warranty: a brand that trusts its product offers a lifetime warranty or at least several years.
• Balanced weight: very light for its size usually means thin walls and poorer insulation.

Fluye is available in several models and sizes designed for different occasions: from the compact version for a purse or backpack to the larger one for hiking, sports, or long days. Common sizes are 500ml, 750ml, 1 liter, and 1.5 liters.

If you're looking for the version with a ceramic interior, there's the Fluye Ceramic Pro 600ml, which, in addition to maintaining temperature, adds an inner ceramic layer that gives the water an even more neutral taste.

For exact availability by model, capacity, and color, the store is always up to date.

It depends on how you use the term. "Stainless steel canteen" and "insulated bottle" often describe the same object: a double-walled vacuum-sealed steel container to keep drinks hot or cold.

The usual difference is in the format: canteens are typically associated with more robust models geared towards outdoor use, hiking, or military use, with a wider mouth or bulkier design. Insulated bottles tend to have more streamlined formats, suitable for car cup holders or daily urban use.

Fluye is an 18/8 stainless steel insulated bottle with double-wall vacuum insulation. For outdoor use, hiking, or sports, it works perfectly, just like any quality steel canteen.

Yes, in terms of materials. 18/8 stainless steel is completely safe for children: no BPA, no plasticizers, no compounds that leach into the water. It's the same material used in many quality school water bottles.

What you should consider is the size and lid design, which varies by model. For school use, 500ml or 750ml sizes are the most common and fit well in backpack cup holders.

Yes. Fluye has different types of lids depending on the model. The wide mouth is the most common: it is easier to clean and allows you to add ice directly. Some models have a sport lid with a mouthpiece for drinking without fully opening.

If you plan to carry hot liquids, always check that the lid is designed for that purpose. Some lids with straws are only intended for cold liquids and do not seal well with steam pressure.

Cold for up to 24 hours. Hot for up to 12 hours.

These times assume normal conditions: pre-conditioned bottle (rinsed with cold water before adding cold drinks, or with hot water before adding hot drinks), ambient temperature of 20-25°C, and occasional opening.

• Frequent lid opening significantly reduces the time

In practice, none. Both terms describe the same principle: a double-walled vacuum insulated container that isolates the liquid's temperature from the environment.

"Thermos" is the more commonly used colloquial word, especially for hot beverages. "Thermal bottle" is used more in the context of sports or daily hydration. The name changes depending on the manufacturer and the channel; the technology behind it is exactly the same.

If your thermal bottle loses heat quickly, there are three probable causes:

• The vacuum is compromised: after a strong impact, the vacuum layer between the walls can break. The bottle still contains liquid, but it no longer insulates. The clearest sign is external condensation when cold.
• The lid does not close properly: heat escapes through the opening. Check that the lid seals correctly and that the silicone gasket is in good condition.

A high-quality stainless steel double-walled vacuum bottle. No other material can match its performance for portable use.

Yes. Fluye works equally well with hot and cold beverages. The 18/8 stainless steel is safe for all types of drinks: water, coffee, tea, infusions, and natural juices.

To keep drinks cold, double-walled steel clearly wins. For health, glass and steel are the two best materials: they don't release anything into the water, are BPA-free, and have no chemical degradation.

Glass has a problem that steel doesn't: it's fragile. It breaks with an impact and is not suitable for sports or backpacking with confidence. BPA-free plastic has improved, but it's still plastic: it degrades over time, can absorb odors, and there are doubts about other additives beyond BPA.

If the criteria are long-term health and thermal performance together, 18/8 stainless steel is the most solid choice for most situations.

Yes. Fluye is a stainless steel thermal bottle suitable for the gym, running, hiking, and any sports activity. The double vacuum wall keeps water cold throughout your session without exterior condensation.

• Gym: The 500ml or 750ml sizes fit well in machine cup holders and sports bag pockets.
• Running: The 500ml is the most common size. Steel weighs slightly more than plastic; consider if that gram matters in your case.

A quality double-walled, vacuum-insulated stainless steel bottle keeps coffee or other liquids hot for 10 to 12 hours. Fluye falls into that range: 12 hours for hot liquids.

There are factors that reduce that time: filling the bottle less than halfway, leaving the lid open, or the liquid not being hot enough to begin with. For coffee, there's a trick that works: preheat the bottle with hot water for one minute before serving. The steel absorbs heat at first, and that shortens the hours if it's not preheated.

Yes. 18/8 stainless steel is one of the safest materials for containing water. It is the same material used in surgery and the food industry precisely because it does not react with liquids.

• Does not release BPA or phthalates
• Does not release metals or residues into the water under normal use conditions
• Does not absorb odors or transfer them to the water
• Does not degrade over time like plastic

It depends on what you prioritize. To minimize exposure to chemical compounds, the two safest materials are glass and 18/8 stainless steel. Both are inert: they don't release anything into the water under normal conditions.

The advantage of steel over glass is durability and thermal insulation. Glass is purer if what concerns you is the taste or absolute purity of the water, but it breaks.

To be honest:

• Higher initial price: a good stainless steel bottle costs more than a plastic one. The difference pays off quickly.
• Weight: they are heavier than plastic. For ultralight hikers, this matters.
• You can't see the liquid level: without a window, you don't know how much is left without opening it.

What is not a real disadvantage: they do not give water a metallic taste. That only happens with low-quality steel or with deteriorated coatings. Well-maintained 18/8 steel does not transfer anything.

No, if the steel is of good quality. 18/8 is an inert material that does not react with water or most beverages. If you notice a metallic taste, there are three probable causes:

• The steel is of lower grade and is indeed leaching something into the water
• The bottle has a deteriorated interior coating
• It has not been cleaned correctly and there are accumulated residues

A new steel bottle may have a slight manufacturing odor the first few times. Wash it well before the first use and it will disappear.

There are two main problems:

Chemical compounds leaching into the water: plastic releases small amounts of its additives into the water, especially when exposed to heat, sun, or the wear and tear of washing. BPA is the most well-known (present in some polycarbonates), but there are others like BPS or antimony from PET that also raise questions in the scientific community. Many bottles say "BPA-free," but that doesn't guarantee that there aren't other additives.

Microplastics: these are plastic particles invisible to the naked eye that detach from the material over time. A WHO study (2018) detected microplastics in 90% of bottled water samples analyzed. Reusable plastic bottles are not exempt either: every time you wash or use them, the material degrades a little more and releases more particles.

What makes an 18/8 stainless steel bottle different is that it doesn't degrade with use. It doesn't release particles, it doesn't crack, and it doesn't absorb or transfer odors. The water you drink after a year of use is the same as on the first day.

Both are safe. Neither releases harmful compounds into the water. The difference is not about health but about use:

• Glass: 100% inert, with no possibility of interaction with anything. But it weighs more and breaks easily.
• 18/8 Stainless Steel: just as safe under normal conditions, more durable, a better thermal insulator, and impact resistant.

If the sole criterion were absolute purity, glass wins by a hair. If the criteria are health plus daily use plus durability, steel is more practical for most situations.

The main concern has to do with phthalates and antimony: compounds that PET (the plastic of most water bottles) can release, especially if the bottles are heated (sun, car, prolonged storage) or if they are reused several times.

Studies associate prolonged exposure to these compounds with effects on the cardiovascular and hormonal systems. The evidence is not definitive, but it is sufficient for several specialists to recommend opting for tap water in glass or steel containers.

Microplastics are plastic particles smaller than 5mm that detach from packaging and end up in the liquid they contain. When you drink water from a plastic bottle, you may be ingesting microplastics without knowing it.

The risk is higher in three situations: when the bottle is heated (sun, car, prolonged storage), when it is single-use and reused several times, and when the plastic shows visible signs of wear. PET, the common plastic in water bottles, releases more particles as it ages or is exposed to heat.

A study published in PNAS (2024) found microplastics in human blood, lungs, liver, and placenta. Research into their long-term effects is not yet definitive, but the WHO has already classified the issue as an emerging public health concern.

Stainless steel does not release microplastics. It does not degrade with heat, does not absorb odors or flavors, and there is no mechanism by which a fragment of steel could inadvertently pass into water.

For daily use, hot water with a few drops of dish soap and a long bottle brush is sufficient. For a deeper clean:

• Baking soda with hot water: Fill the bottle, let it sit for 30 minutes, and rinse. This removes residual odors and light deposits.
• Diluted white vinegar: For limescale stains or mineral deposits. One part vinegar to three parts water, let it sit for 30 minutes, and rinse thoroughly.

We do not recommend dishwashing the bottle body. The intense heat of the cycle can compromise the vacuum between the walls over time and reduce thermal performance.

The lid, however, can often be put in the dishwasher (avoiding the hottest cycle), but this depends on the model. Please check the specific instructions for your lid.

Hand washing with hot water and dish soap is sufficient and extends the life of the bottle.

Stainless steel does not absorb odors, but the residue left inside does. The most effective solution:

• Baking soda with hot water overnight: eliminates almost any residual odor
• For persistent coffee odor: diluted white vinegar, 30 minutes
• Leaving it to dry upside down with the lid off after each wash prevents moisture buildup, which is the main cause of musty odors

If the bottle smells even after a thorough wash, the source is usually the silicone gasket in the lid. Disassemble it, clean it separately, and let it dry completely.

Practically any drink: water, coffee, tea, infusions, natural juices, smoothies, sparkling water.

For highly acidic liquids (vinegar, very concentrated citrus juices): 18/8 stainless steel can handle them without problems for normal use, but if left unwashed for several days, some residue may accumulate. It is not dangerous, but clean regularly.

Stainless steel withstands most everyday impacts without breaking. It can dent with strong impacts, but it doesn't shatter like glass or crack like plastic.

Fluye's wall thickness is designed for real resistance, not just to be lightweight. And yet, the weights remain reasonable for daily use. As a guide:

• Fluye Ceramic Pro 600ml: 340g
• Fluye Sport: 390g

For comparison: a standard 500ml plastic water bottle filled with water already weighs 500g from the water alone. Empty, it weighs less than half the water it will carry.

The most important thing about impacts: a very strong impact can compromise the vacuum between the walls. The bottle will still hold liquid without leaks, but it will lose its insulating capacity. The sign: if, after a significant impact, it no longer maintains the temperature as before, the vacuum may have been affected.

The most common, with cause and solution:

• No longer maintains temperature. Most likely cause: the vacuum between the walls is compromised, usually by a hard impact. It cannot be repaired. At Fluye, the lifetime warranty covers this case if there is a manufacturing defect.
• Drips or leaks. Check the lid gasket. Silicone gaskets wear out and are easy to clean or replace. If the leak comes from the bottle body, the problem is more serious.

Fluye was born with a rather simple idea: access to clean water is a fundamental right, not a privilege. And nine years ago, in Peru, we saw that a quality reusable bottle could be a concrete part of the solution to two real problems.

The first: access to water. In many communities in Peru, there are people who don't have potable water at home. They depend on water trucks or walking for hours to get it. We wanted every bottle we sold to finance a real, concrete solution for this. Fog nets are structures that capture moisture from the air and convert it into real drinking water. That's what every Fluye finances.

Second: the amount of single-use plastic we generate every day. Someone who drinks bottled water can produce hundreds of plastic bottles a year. A good reusable bottle eliminates that from day one.

Over time, the scope grew. Today, we also fund educational projects and impact programs for communities affected by climate change and the growth of tourism, which year after year transforms the environments where these people live and work.

For every Fluye sold, 5.4 liters of drinking water per month are funded for communities in Peru through fog catcher projects managed with the NGO Los Sin Agua.

Fog catchers are structures that capture moisture from coastal fog and convert it into real drinking water. Each installation provides up to 300 liters daily for communities that do not have access to a water network.

Up to 150 plastic bottles per year, if Fluye completely replaces your bottled water consumption.

What is constant: the 5.4 liters of drinking water funded monthly by each Fluye sold, regardless of your previous habits.

The Peruvian coast has areas with dense fog called "garúa." This moisture does not fall to the ground as rain, but it can be captured.

Fog nets are polypropylene meshes stretched over metal structures oriented perpendicularly to the wind. Fog droplets collide with the mesh, grow larger, form drops, and fall by gravity into a collection channel. From there, the water reaches reservoirs and the community's distribution system.

A 40m² fog collector can generate between 200 and 400 liters per day under optimal conditions. It's real water, with almost no maintenance costs, for communities that would otherwise have to buy it from tankers or walk for hours to get it.

That's a fair question. There's a lot of greenwashing in the market.

• We publish dated photos of projects, not renders or generic images
• We work with the NGO Los Sin Agua, which is independently verifiable
• The numbers we publish (5.4 liters/month, 300 liters/day per fog collector) have a visible logic and are calculable
• When the numbers are small, we publish them anyway

What we don't do: paid impact certifications that cost money but don't involve real independent verification. We prefer to show directly.

There are several brands that link their sales to social or environmental projects. The differences are in the details: what percentage of the sale goes to the project, whether the project is in-house or external, whether there is independent verification, and whether they regularly publish the numbers.

To assess whether any brand's impact is real, you should ask them the following questions:

• Can I see recent, dated photos of the project?
• Is there concrete data per unit sold?
• Is the NGO partner independently verifiable?
• Do you publish when the numbers are small or only when they look good?

Signs of greenwashing:

• Vague language: "committed to the planet," "eco-friendly," with no concrete numbers behind it
• Self-designation or paid certifications without independent verification
• They don't publish the negative aspects: carbon footprint of shipping, packaging, manufacturing process
• "Purpose" only appears in marketing, not in operations

Signs that they are serious:

• Specific and frequently updated data
• They admit what doesn't work or what they haven't achieved yet
• The impact partner exists and is verifiable outside the brand's website
• They publish the numbers even if they are small

Lifetime warranty. If Fluye fails due to a manufacturing defect, we replace it. No time limit. No asterisks.

It's not a marketing gimmick. The lifetime warranty exists because we are convinced the product will last, and because if it didn't last, it would be our problem, not yours.

A cheap plastic bottle lasts between 6 months and 2 years. A quality steel bottle with a lifetime warranty lasts as long as you want it to. The cost per year of use decreases every year you use it.

Furthermore, if there's a defect at any time, you're fully covered. If you keep the bottle for a year without using it, the warranty hasn't "expired."

There are brands with more history and recognition than Fluye. All of them use quality stainless steel with double-walled vacuum insulation. The real differences lie in what's behind them:

If brand recognition matters more than the product itself, there are options with a longer history. If you want equivalent quality at a more competitive price, with real social impact and local support, the answer is on the page you are reading.

Yes. Fluye can be customized with your company's logo for corporate gifts, employee onboarding, events, or merchandise.

It's not just about putting a logo on a bottle. Each customized Fluye continues to generate the impact of providing drinking water. That gives your employees or clients more than just an item with your brand.

And there's a statistic that changes the conversation about corporate merchandising ROI: a Fluye lasts over 6 years. The average employee tenure today is 2 to 3 years. This means that the Fluye you give them on their first day, they take with them when they change companies, use it in their next role, and keep it long afterward. Your brand travels with them throughout that cycle, in meetings, on trips, and on the desk of their next company.

Yes, we ship throughout Europe. Estimated delivery times:

• Peninsular Spain: 2-3 business days
• Western Europe (France, Germany, Italy, Portugal...): 3-5 business days
• Rest of Europe: 5-8 business days

For the exact shipping cost to your country and if free shipping applies, the store automatically calculates it in the cart.

Write to us. If there's a defect, we'll fix it: replacement or full refund, whichever you prefer.

There's no need for much justification. If something arrived damaged, it's our problem. Send a photo of the defect and your order number, and we'll respond within 24 business hours.

In order of importance:

• Interior material. 18/8 stainless steel or higher, with no plastic coatings inside. This is the most important difference for long-term health.
• Double-wall vacuum insulation. Not just "double wall", but vacuum between walls. Without a vacuum, the insulation is much less effective. How to check: a real vacuum bottle does not condense on the outside with cold liquid inside.
• BPA-free in lid and gasket. Not just in the body. The lid is the most frequent point of contact.

Honesty first: we are a bottle brand and we are not neutral on this question. But we can tell you what criteria to use to evaluate any option, including ours.

Good value for money in a thermal bottle means: 18/8 stainless steel, genuine double-wall vacuum insulation, a lifetime warranty, and a price between €25 and €45. Above €60-€70, you're paying for the brand. Below €20, you're taking a quality risk that probably isn't worth it.

Fluye enters that segment and adds something that most do not have: verifiable social impact. Each unit finances 5.4 liters of drinking water per month for communities in Peru. We don't say this to justify the price, but because it is relevant information for comparing similarly priced options.