Can You Put Coffee in A Hydro Flask? (Explained)

Pouring coffee from a hydro flask.

Coffee has unknowingly become one of the most important daily doses of energy and happiness for us.

No matter how busy the schedule gets, it has become ritualistic practice to jolt on the caffeinated drink after waking up or to avoid an afternoon slump. Not only the drink provides us with amazing health benefits, but it’s also the perfect energy fix that helps us pull through the busiest days.

Many people also need the drink to pull an all-nighter and to stay alert.

With the busy schedule that people tend to follow nowadays, it’s quite tough to prepare the desired variety of coffee multiple times for everyone.

So how are you planning on holding the warmth or coldness and flavors of the drink throughout the day?

Short answer: Yes you can put coffee in a hydro flask. To keep the temperature of the coffee perfect, it’s better to buy a well-constructed flask with standard mouth lids.

The following sections have a better explanation of the related queries.

Continue your ready to get an in-depth explanation!

Does a hydro flask keep coffee hot?

hydro flask in a stream

Yes, hydro flasks will keep your coffee hot. The flasks are usually made with 18/8 stainless steel that is non-reactive to coffee.

The lids are made with thick plastic that has a rubber gasket to make the container airtight. Plastic is an insulator and it will keep heat from going out or coming inside of the flask. Similarly, the rubber gasket helps in preventing the warm air to go inside the bottle and warm the liquid and vice versa.

The flask will keep your coffee hot for a longer period without altering the taste. This is an age-old tradition that has been followed in households for a quite long time.

You need to be aware of how the lid is protecting the bottle since leakage or gap between the lid and the bottle may lead to infusing gas in our out from it.

Can you put iced coffee in a hydro flask?

You can keep iced coffee in your hydro flask without worrying. The pH of coffee isn’t highly acidic so it shouldn’t react with the stainless steel.

The possibility of the steel reacting with iced coffee is lower than that of hot coffee. Iced coffee is colder and it’s unlikely to react with any of the material inside the container or bottle.

The vacuum insulation of the bottle will prevent the warm air from outside from coming inside the bottle so you can keep the coffee cold for a long period.

The excellent insulation of the flask will keep the water chilly for about 24 hours. The vacuum construction of the flask helps in protecting the temperature of the liquid poured inside it.

However, iced coffee contains a few ice cubes and with time this ice will eventually meltdown no matter how well the flask is working. So, the iced coffee will give the best cooling effect within the first 6-12 hours depending on how well it’s being stored.

How long does a hydro flask keep iced coffee cold?

Typically, your coffee will be cold for 24 hours in contrast to 12 hours of hot coffee.

The cold liquid generally is denser compared to the hot liquid. So the overall cooling effects of the iced coffee will be more prominent in the case of cold coffee.

However, the ice tends to melt at one point in time and after that period, the liquid may tone down a bit. It’s safe to drink even after that so don’t worry.

How long does coffee stay hot in a hydro flask?

A black hydro flask
A hydro flask is a convenient tool for keeping your coffee warm or cool.

From personal experience, I can conclude that a hydro flask can be used for keeping the liquid hot for about 12 hours even when it’s freezing outside. That’s how it’s made.

However, this timeframe is considered when you are starting to boil water at the temperature and your coffee is rarely that hot. After 12 hours, the coffee will still be hot but not the smoky hot that you might be expecting.

Coffee generally comes with a temperature between 50-65 degrees celsius and a hydro flask can hold this temperature for about 6 hours. By the next 6 hours, it’ll eventually turn into a lukewarm liquid.

What are the ways to keep your coffee hot in a hydro flask?

Some of the most convenient tips that you can use to enjoy your warm coffee throughout the day are mentioned below:

  • Pre-heat the inside of the bottle to warm the stainless steel inside the flask.
  • Use a large amount of coffee because more energy will be needed to reduce the temperature of the coffee.
  • Use Standard mouth lids that are thicker and better at insulation.
  • Pour the coffee into the hydro flask as soon as the drink is boiled and prepared.
  • When you’re not drinking keep the lid closed so that warm air doesn’t escape through the flask.
  • Don’t put the flask in the freezer or fridge.
  • Use an insulating pouch to add an extra level of insulation protection.
  • The obvious one is to drink the coffee as soon as possible before it loses heat eventually.

The same tips go for keeping the coffee cold as well. As long as your flask is doing great with insulation properties, you don’t have to worry about your hot coffee turning cold or cold coffee turning hot.

Can you put hot coffee in stainless steel?

You can put coffee in a stainless steel container without worrying about the drink ruining the container as coffee isn’t acidic enough to damage stainless steel.

To know more about the acidity of coffee, you can read my post here.

This is one of the most debated issues whether to put hot coffee in a stainless steel jar or not.

Many wonder whether the acidic component of coffee will react with the stainless steel of the flask and potentially damage both the flask and coffee.

Stainless steel generally reacts with acidic substances that can leech your drink. However, coffee is not that acidic to undergo any chemical reaction with the metal.

The pH level of coffee is around the average value of 4.85 to 5.10. Certain drinks such as soda, lemon juice, etc are much acidic than coffee. If you add milk to your coffee, it gets pretty much pH neutral.

So, you can put your hot coffee into the flask without having any second thoughts. The inside metal body won’t damage the flavor of the drink since the acidity level of the coffee doesn’t corrode the stainless steel. Make sure you have purchased a well-known brand of hydro flasks with good construction and service.

The pH level of different commonly consumed drinks:

Type of drinkpH level
Black Coffee5
Lemon Juice2
Soft drink3
Coconut water5-5.4
Maple syrup6.5-7.0
A table containing the pH level of different drinks.

Does keeping coffee in a hydro flask affects its taste?

hyrdo flasks lined up leaning against a rock

According to common perception, the stainless steel that is used for making the flask shouldn’t affect the taste of the drink put inside.

Most of the coffee varieties in the cafes are usually made in stainless steel machines and they do taste the same. Some people, however, tend to claim that the flask alters the taste and makes the coffee somewhat bland.

Stainless steel doesn’t absorb any aroma or flavor. The chromium component of the steel helps the flask to be non-reactive and this is why the metals in used in everything from cutlery to cookware.

However, due to differences in the construction of the flask among manufacturers, the flask may sometimes impart off some metallic flavors into the liquid inside.

Some Reddit posts suggest that the flask changes the flavor of the drink and seems like a washed, tasteless version of the original.

While some have claimed the taste change as a trivial variation but a few have regarded it as damaging the whole coffee.

Most of the time, this non-uniform fusion of added flavor in the coffee is due to problems during manufacture. In some cases, this variation over flavors might occur due to the reaction between thousands of coffee’s bioactive components with the metal.

Can you put coffee in a hydro flask cup?

This is just a tumbler-like cup and works just fine as a hydro flask. The cup or mugs is made from a similar material used for the hydro flask and thus offer a similar function.

You can use hydro flask cups for your coffee. The cups and mugs are also made from 18/8 stainless steel which is safe to drink coffee from.

The cups are double-walled and work great as an insulator that should keep your coffee warm for the alone period.

Apart from these, the hydro flasks cup is convenient since it’s easy to carry and durable.

Final Thoughts

You can put coffee in a hydro flash without worrying about any potential side effects and changes in the drink.

Not only the flask will keep the drink warm and cold depending on the state, but also makes it convenient for people to store coffee for longer periods.

In theory, the stainless steel of the flask won’t make any changes in the coffee’s taste and flavor. The acidic level of coffee isn’t high enough to cause cross-reaction and produce unwanted leaching of the drink.

Ensure a proper standard lid for the flask so that the air doesn’t escape easily from inside the bottle or go inside from the environment.

Take a look at this video reviewing hydro flasks to know more:

Check out this video to know more.

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Matt Marshall

As I learn more and more about coffee and coffee products I want to share all my learnings with you here on this website. I hope you find my articles useful and entertaining to read.

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