It’s understandable if you feel like pouring hot water in a glass French press could end badly. Is it really a problem and should you use boiling water in the first place? Find out below.
Pouring boiling hot water in a French press is not a problem as long as the carafe is made out of borosilicate glass or stainless steel. Plastic or normal glass French presses should be avoided. For taste reasons, using 94 degree Celsius water in a French press is better than boiling water.
This Veken French press (Amazon) is made from thickened borosilicate glass which can easily handle boiling water. It looks nice and is very affordable to boot.
Why is that and how can you select the right French press that can handle all the heat you want to throw at it, keep reading.
Is it safe to pour boiling water in a French press?
You might be afraid that pouring hot water in a glass container could crack it. And nobody wants to have glass in their coffee and you don’t want to regularly buy a new French press.
Most French presses are made from glass so it seems like pouring boiling water into it would be a bad idea. Most good French presses are made from borosilicate glass. Borosilicate glass is a type of glass with silica and boron trioxide mixed in. This creates a type of glass that expands very little with heat. This makes this type of glass very resistant to thermal shock.
Not sure how to make tasty coffee in a French press? Click here for my step-by-step guide.
Simply said, that means that a good quality French press carafe has no problem with hot water being poured into it, it won’t crack or break.
The important part of that sentence is “good quality”. There are some French presses that are made from different materials. Some of those alternative materials are good but other materials are not. Let’s go over a few;
- Stainless steel: Stainless steel stands up very well to heat. Yes, steel expands with heat but boiling water is nowhere near hot enough to cause problems.
- ‘Normal’ glass: If the material is not specified as borosilicate, it’s likely normal glass. Normal glass is not suitable for a French press. It doesn’t handle heat properly and breaks more easily.
- Plastic: The cheapest French presses are made from plastic. While plastic can handle heat and doesn’t break easily. Hot liquids and plastic containers are not a good combination for health reasons even if they’re BPA free. Plastic French presses also don’t last long and usually don’t brew coffee that well anyways.
So when shopping for a French press, make sure the carafe is either made out of borosilicate glass or stainless steel. Plastic should be completely avoided and if the type of glass isn’t specified, assume it’s not what you want.
The price difference between bad and good French press isn’t that big anyways. You can get a good one for $25-$35. Sure the cheapest French presses cost around $10 – $15 but for $10 extra you get something so much better, it’s not worth saving that money.
A good french press that is made from borosilicate glass, looks good and does a good job filtering is the TimeMore press. It’s pretty affordable too. Check it out.
Does French Press coffee taste good using boiling water?
So while it’s not really a problem to pour boiling water (or even hotter liquids) into a good quality French press, it might not be the best idea to use boiling water if you want a good tasting cup of coffee.
If you use water that’s too hot, it can extract too much from the grounds. Extracting too much can cause the coffee to become bitter. It’s better to let the water cool down a little bit before you pour it in your French press. If you want to be precise, 94 degrees Celsius is the temperature to shoot for.
Most people don’t want to pull out the thermometer or even have a temperature controlled kettle. So to get your water temperature in the right ballpark after boiling you can wait about 30 seconds if you boiled in an open pot, or up to 1 minute in a well-insulated kettle.
If you feel the coffee is too light or maybe even a bit sour with that much waiting, halve that time the next brew and see if that’s better. Of course you could get a simple thermometer and be sure.
Knowing how far to press down is also an important part of the brewing process. Click here to find out more about that.
How to keep your French press coffee hot for longer
You might want to start with the hottest water possible because you like your coffee hot. However, using boiling water isn’t the best way to accomplish that. You can end up with coffee that doesn’t taste that good and if you don’t change anything else, the coffee will still cool down during the brewing period.
Also, French press coffee is usually hot enough just after brewing but it cools down quickly if you don’t drink it immediately. So changing the temperature of the water isn’t actually going to be very effective at keeping it hot.
There are two changes you can make that keep your coffee hot for longer;
- Preheat the carafe: You’re boiling water anyways. Use a little bit of water to preheat the French press. Before scooping in the coffee, pour some boiling water in the carafe and swirl it around. This heats up the glass or other material. So when the brew water hits, it cools down less because the glass is already hotter. This means a more constant brewing temperature as well which can improve the taste a little.
- Use a stainless steel French Press: Ditch the glass, get a stainless steel French press. Stainless steel brewers are often double walled. That’s the same design as a thermos. This means there is a layer of air between two sheets of steel. This is a really good insulator so the coffee doesn’t lose much heat and you can keep your brew hot for hours.
One or both of those tips should help you keep your coffee hot quite a bit longer. Fresh coffee is always better though so getting a smaller press and making more batches when you want it can also be a good option.
Favorite French Press Brewing Tools
Here are some things that help you brew better coffee:
- French press: This beautiful stainless steel Meuller French press (Amazon) is high quality yet affordable and the double filtration system means less sediment in your cup.
- Grinder: Fresh beans have to be ground. A hand grinder like the Hario Slim (Amazon) is affordable yet effective hand grinder that will improve your cold brew.
- Scale: The amount of grounds you use makes a big impact on what your cold brew tastes like. A simple set of scales will makes your brews more consistent. I’ve been using this one (Amazon) for over a year with great success. Not the most aesthetic but effective.