The Best Reusable Water Bottles That Aren’t Stanley Cups

The eight-glasses rule isn't exactly accurate, but it's a solid starting point. Since water intake is highly individualized (kind of like your bottle), it's best to consult your doctor about the right amount for you. Several lifestyle factors can influence your hydration needs. If you're active or sweat a lot, for example, you generally should increase your intake to make up for losses. Warmer temperatures can also make us thirstier.

On the other side, it's also possible to drink too much water. According to Harvard Health, the daily fluid intake for healthy adult men (including both drinks and food) should be about 3.7 liters a day, while for women, it's around 2.7 liters. Drinking too much water can also cause overhydration and sodium levels to drop to dangerous levels in a condition called hyponatremia. Certain medications can lead to water retention, which is why it can't hurt to double-check with your physician during your next check-up. In the meantime, if you're not thirsty and your urine is colorless or light yellow, you're likely doing great, sweetie.

An insulated water bottle consists of a double-wall construction with insulating materials that prevent heat transfer. Insulated bottles are heavier and can typically hold less water compared to their uninsulated counterparts, given similar exterior dimensions. However, the advantage is that they are typically vacuum-sealed to better maintain the temperature of the liquid inside for far longer periods.

Condensation is typical in non-insulated water bottles, since the beads of water form on the exterior of the bottle. Packing the bottle inside your bag can be inconvenient, as the condensation comes into contact with your personal items. It can damage your bag and other things inside it. Insulated bottles are made of stainless steel and other similar materials that are durable and resistant to damage. The longer lifespan means less waste in manufacturing these water bottles, and you can maximize these resources to reduce environmental impact.

Insulated water bottles are more expensive, since more technology and a complex manufacturing process are required. But you are also paying for reusability, since you can save more money in the long run as you won’t need to replace your water bottles as often as you would with disposable, single-use plastics.

For hiking and outdoor climbing trips, you may prefer uninsulated bottles because it means less weight to lug around, and the concern is to have enough water rather than cold water. For everything else, insulated works just fine.

Even if they never hold anything but water, bottles get gross. Mold can grow quickly, especially if you leave the cap on. Straws and mouthpieces accumulate bacteria, oils, and grime from your mouth, and any dirt and dust they pick up in your backpack.

Some bottles can go right in the dishwasher, but be sure to take everything fully apart first, like any silicone pieces that can trap bacteria. For lids that have more nooks and crannies, we recommend hand-washing by soaking them in soapy water and then scrubbing.

Get yourself a bottle brush and straw brush—many kits are available that include both. Even if you don't use straws, the smaller brush can be used to get into any crevices. There are special bottle-cleaning tablets around, but cleaning with regular dish soap works perfectly fine.

Plastic bottles have a tendency to trap odors over time. You can fix this by putting a teaspoon of bleach and a teaspoon of baking soda in the bottle, filling it up with water, and letting it sit overnight. Rinse it out well the next day.

Some water bottle companies use lead soldering in the manufacturing of their vacuum-sealed bottles. The viral Stanley tumbler is one of them; despite stating that no lead comes into direct contact with the consumer, the company has confirmed that pellets, some of which include lead, are used in the manufacturing process to seal the bottom of the cup. Ah, semantics. The lead is enclosed in stainless steel on the bottom of the cup, and if your bottle isn't dropped or otherwise damaged, it should not come in contact with your drink or skin. However, enough brands have moved toward other methods that we don't think it's necessary. The risk of exposure might be very low, but it should be zero.

We also reached out to more brands to find out whether they also use lead. (Yeti didn't respond to emails, but the brand's FAQ section confirms it uses lead for sealing its insulated cups. We recommend the plastic bottle above if you like the brand and want a lead-free version.)