How to Tell If Your Water Bottle Is Aluminum or Stainless Steel

As you know from reading this blog, drinking from metal bottles is recommended over reusable plastic ones. That’s because plastic may contain bisphenol A or BPA. Supposed BPA-free plastics aren’t even always free of the chemicals.

Even if you did luck out and get a true BPA-free reusable plastic water bottle, you have to consider the possibility of other chemicals leaking out, such as phthalates.

To truly drink chemical-free, you’re ready to make the switch over to metal water bottles. There are two common types of metals used in the production of reusable bottles: aluminum and stainless steel. How can you tell if your water bottle is made of one or the other?  There are many ways, but one of the biggest differentiators is price.

The Best Aluminum  and Stainless Steel Water Bottles I Found

I decided to go on a little research and find out the best water bottles that is suitable for almost anything. You can bring it with yourself while you are working out, hiking, or while doing any other activity where you may want to make sure you stay hydrated without harming your body. And here what I found:

Aluminum Water Bottles:

Or check my buying guide for this aluminum water bottle here

Stainless Steel Water Bottles:

Or check my buying guide for this stainless steel water bottle here

[VIDEO] Get The Facts Water Bottles: Stainless Steel Vs. Aluminum

Listen to the facts about stainless steel bottles on this demonstration video by Animal Man Survivor using Klean Kanteens and aluminum bottles, there is a clear and obvious winner.

What Is the Difference Between Stainless Steel and Aluminum?

Aluminum and stainless steel can look an awful lot alike. Sometimes even holding up two metal bottles to feel the weight difference isn’t enough to tell which is which. What are some other differences between the two metals?

Here are a few:

  • Aluminum has the tendency to change food flavor and color, which means your water or other liquids may taste a little funny. That’s not the case with stainless steel.
  • In addition to being heavier, stainless steel bottles are more durable, with a strength aluminum does not possess.
  • Stainless steel has better thermal properties than aluminum. If you crank up the heat on aluminum to 400 degrees Fahrenheit, it won’t outright melt, but it will soften. Stainless steel will not and can withstand temperatures even above 400 degrees.

biggest differentiators

Which Is a Better Conductor?

Like we said before, price is one of the between stainless steel and aluminum. Stainless steel bottles are often more expensive than those made of aluminum.

Metal is often measured by its electrical and thermal conductivities. Electrical conductivity is how easily a metal can generate electricity. Out of the two metals, aluminum is the clear winner here. If you’ve ever noticed, overhead power lines are typically encased in aluminum. That’s because the metal is less likely to corrode and is great at conducting electricity.

When it comes to thermal conductivity, which is the ability to generate heat, aluminum wins again. That’s why it’s a trusted material in home air conditioning units and car radiators.

Is Aluminum or Stainless Steel Better for Water Bottles?

While aluminum is the top choice for generating electricity or heat, when it comes to the water bottle you drink out of, you should choose one made of stainless steel.

Stainless steel bottles often have no plastic liners. Already then, there’s no risk of BPAs, phthalates, and other chemicals leaking into your water and other beverages. With non-reactive properties, even if you warm or up chill a stainless steel bottle, its properties won’t change.

Now, the stainless steel that is used in manufacturing is not the same that your reusable water bottle is made of. The material is known as food-grade stainless steel. There are several grades the steel can receive, like 316 or 430.

Grade 316 stainless steel often contains nickel and chromium. These other metals allow the stainless steel to heat up to 1,472 degrees (and yes, that’s Fahrenheit) without melting or degrading in quality. It tends to be salt-proof, so chlorides, alkalies, and acids will cause no damage.

Then there’s grade 430 stainless steel. This has less nickel but still contains chromium. For that reason, it tends to cost less and may be more commonly used in kitchens across the country. If your metal cooking products are magnetic, then they’re grade 430. This stainless steel is magnetic due to the ferritic alloys contained within.

Is It Safe to Drink Water from Aluminum Bottles?

What if you bought an aluminum bottle thinking it was stainless steel? You might have even wanted an aluminum bottle because you knew it was safer than plastic and it was cheaper than stainless steel. Is it safe to drink water from this bottle?

“More on this Topic Read: Which Bottled Water is the Safest to Drink?”

Not always. Aluminum bottles cannot withstand beverages with high acidity, and damage to the bottle could occur. To prevent that, many aluminum bottle manufacturers add an epoxy or enamel liner within. Epoxy could contain BPAs, which means you might as well stick to stainless steel.

Not only that, but you might not be able to recycle your bottle when you’re ready to part with it because of the plastic liner. You cannot put your aluminum bottle in the dishwasher and must always wash it by hand. Since these bottles tend to have narrow necks, that’s not very easy to do.

Is Stainless Steel Toxic to Humans?

Say you fill a stainless steel bottle with water and set about on your way. When you go to take a drink, you get a metallic flavor. It’s off-putting, but you figure it will go away after a few sips. It doesn’t.

That doesn’t mean that stainless steel is toxic. What you’re tasting aren’t chemicals, but rather the metals within the bottle.

As you might remember from our article about BPAs in plastics, sometimes metal water bottles develop a crust after use. This is not a sign of stainless steel toxicity. It’s just what happens when water and metal mix, especially if it’s hard water. By using warm water, baking soda, and diluted vinegar, you can treat the problem. Cleaning out the bottle ought to do the trick, too.

Know the best water bottle you can use: The Best Water Bottle.

Do Stainless Steel Water Bottles Keep Drinks Cold?

There’s nothing worse than stashing a reusable water bottle in a fridge or freezer for an hour, bringing the drink with you, and finding the temperature is now lukewarm. If you want to avoid such an unfortunate situation, stainless steel water bottles are the answer.

Aluminum might be a great conductor of heat and electricity, but stainless steel is awesome at insulation. Just like when you add insulation to the walls of your home, the job of insulating materials is to trap in warmth or coolness and keep it consistent. In this case, we’re talking about cold water.

That means you can fill your stainless steel bottle with water (or your other favorite liquid), stash it so it gets cold, and then enjoy a cool beverage all day. Seriously, you may enjoy as many as 24 hours of frostiness, even if the stainless steel bottle hasn’t been near a source of cold all day.

You are not going to get that from water bottles made of any other material, including aluminum.

Can You Put Them in the Freezer?

There is one teeny-tiny downside of owning a stainless steel water bottle: you generally can’t freeze it. That’s come up on this blog before, but it’s worth reiterating now.

The reason? Well, there are several. The bottle can break during freezing. As water hardens and solidifies, expansion occurs. If you filled the bottle to the top (which is not recommended if freezing it), then the bottle will certainly break. Even if you only poured 3/4ths of water like recommended, the stainless steel bottle can still break. The same can be said of aluminum. This metal, like any metal bottle, does not fare much better in the freezer.

Another reason you don’t want to freeze your metal bottle is that rusting can occur. A buildup of rust will only add to that unpleasant metal taste that stainless steel bottles sometimes possess.

Even though you can’t freeze your metal bottle, you can still put it in the fridge. That will be enough for a stainless steel bottle to stay cold all day (and all night). If you don’t have time for the bottle to sit in the fridge, then try ice. This will still trigger the insulating properties of stainless steel.

What About Lemons? Can You Add Them to a Stainless Steel Water Bottle?

The acidity of lemons may be too much for aluminum bottles, but what about stainless steel? While there’s no need to worry about the lemon causing rust or corrosion, there’s always been a myth that lemon can change the flavor of stainless steel and discolor it.

While the color of the bottle’s interior will not change, the flavor of your beverage might be a little different. Then again, if you’re adding lemon to your stainless steel water bottle, it’s to augment the flavor.

You can absolutely add lemon to a stainless steel water bottle, then. Just make sure the bottle is indeed stainless steel and not aluminum. Lemon could damage aluminum bottles in a hurry!


When it comes to choosing between stainless steel and aluminum water bottles, the former is the much-preferred choice. Stainless steel can withstand very high temperatures (thousands of degrees Fahrenheit) with no signs of structural damage. It may not conduct electricity or heat well, but its insulating qualities will keep your drinks cold.

While you can’t put a stainless steel water bottle in the freezer, it can go in the fridge

. It’s dishwasher-safe, and you can add ice and lemon to your beverages for a fun, fruity twist.



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