A barista's guide for how to make iced coffee from hot coffee

Our barista shares the secrets for how to make iced coffee from hot coffee. Expert advice for brewing over ice, Japanese style, or letting your coffee cool.

how to make iced coffee from hot coffee: a glass of iced coffee being poured over ice
(Image credit: GettyImages)

Making iced coffee from hot coffee is straightforward. However, if you're simply pouring hot coffee over ice, you won't be getting the best results. Your coffee will be bitter and overly diluted, spoiling the earthy balance of sweet and acidic notes.

As a barista, I've been trained to make iced coffee in a number of ways. Japanese iced coffee requires you to brew coffee directly on to ice, whereas typical iced coffee undergoes a slower cooling process, protecting the balance and body of your brew. 

I reached out to the barista community to find extra tips and tricks for making iced coffee from hot coffee. Without fail, everyone recommended using a coffee maker. If you use top quality machines, you'll make an infinitely better brew.

Whether you want to spice up your iced latte or you're looking for something a little sweeter, I've spoken with chefs and baristas to find the perfect method for consistent and quick iced coffee.

What is iced coffee?

two glasses of iced coffee being poured next to each other, simultaneously

(Image credit: GettyImages)

Not to be confused with cold brew, iced coffee is coffee which has been brewed hot and then cooled down, normally with ice. Brewing at a higher temperature and pressure gives a much fiercer extraction of the essential oils in coffee beans, so the flavor profile can be quite bitter. As your coffee cools, it will oxidise and become more bitter. Americanos in particular can have a real tang. That's why iced coffees often have milk added to them; the sweetness re-balances the flavors.

Contrary to popular misunderstandings, iced coffee is not the same as cold brew. I have a guide to making cold brew coffee, which explains the process in detail. Rather than use high pressure and temperatures, cold brew takes at least 12 hours. Over that time, the coffee grounds remain at room or refrigerator temperature, so their flavors are extracted slowly and delicately. This gives a much sweeter, mellow flavor, but the results need to be diluted with water or milk.

How to make iced coffee

A black iced coffee on a marble countertop

(Image credit: GettyImages)

There are a few ways to make iced coffee, mostly mixing up the order of ice and coffee. I spoke with baristas to find the perfect process for every method. If you're in a hurry, there's no problem with pouring your hot coffee over ice. However, if you are willing to dedicate a little more time to your coffee, you'll reap the rewards. Slowly cooled coffee can be much more balanced and aromatic, plus you can prep ahead, so you always have iced coffee ready.

Slow cool

an iced coffee on a wooden countertop

(Image credit: GettyImages)

The slow cool method is self explanatory and is also a great way to stop extra hot coffee from going to waste. Simply brew your coffee, using whichever method you prefer. Then, let it cool to room temperature, or place it in the refrigerator to speed the process up a little. It'll take a while, so it's good to have your coffee cooled a few hours before you want it. 

If you have some hot coffee spare, you could make coffee ice cubes. Pour them into an ice cube tray like this at Walmart. You can put these into your hot coffee, or just fill a jar with coffee ice cubes and wait for them to melt. Using ice cubes or the slow cool method requires more planning and preparation, but it pays off. Kayla Stavridis from Barista HQ told me that 'from my experience letting the coffee cool naturally to room temperature before refrigerating has always resulted in a less bitter taste'. This is because cooling, already bitter coffee quickly, oxidises your cup of joe, outbalancing the subtle, sweeter notes.

Barista HQ
Kayla Stavridis
Barista HQ
Kayla Stavridis

Kayla Stavridis is the Head of Marketing at Barista HQ. She's always up to date on coffee trends , especially cold brew and iced coffees too. 

Flash Brew

A drip coffee maker brewing iced coffee on a table

(Image credit: GettyImages)

The flash brew method, also known as Japanese cold brew, is the quickest and easiest way to make iced coffee. You'll have probably tried it by accident. If you like black coffee, this is likely to be your method of choice, since it keeps the bitter, acidic, and sweet notes of normal coffee. I spoke with Maryna Gray, coffee expert and Director of Coffee at Bean Box to find her perfect ratio for iced coffee. She recommends using 1.8 oz of coffee, brewed with 18.4 oz of water. Once you have brewed it, using your preferred method, you can pour it over 10.4 oz of ice in a glass carafe. The coffee will melt the ice cubes, so transfer them into a new iced coffee cup, filled with ice, and it'll be ready to drink. If you want to adjust the quantities, Maryana's perfect ratio is one part coffee to ten parts water and six parts ice. 

Coffee Expert
Maryana Gray
Coffee Expert
Maryna Gray

Maryna is a director and coffee expert at Bean Box. She's tested a variety of different coffee recipes, from adding olive oil and lemon to coffee, to iced coffee and cold brew.

Oli Base, professional barista, told me that her preferred method used a drip coffee maker. She said 'the best way to make an iced coffee quickly is to brew a drip coffee directly onto coffee ice cubes. if you have a drip coffee machine, then fill your carafe half way up with coffee ice cubes and then brew half a carafe of coffee as you normally would'. If you don't have coffee ice cubes, just make sure that your coffee is twice as strong, so that the normal ice cubes don't dilute it too much.

Professional barista
Oli Base
Professional barista
Oli Base

Oli has been a barista for eight years and is the founder and managing editor of Drinky Coffee, a coffee blog. He has extensive experience, crafting, brewing, and tasting iced coffees.

Quick espresso method

An espresso in a glass under the portafilter of an espresso machine

(Image credit: GettyImages)

If you like the sound of flash brew, but don't have much ice, this is a brilliant method. Make an espresso shot, which will be warm, but then dilute it with as much ice cold water as you would have used hot water. Pop in a couple of coffee ice cubes and your coffee will be perfectly iced. You can — dare I say — do the same with instant coffee. Just make sure that all of the instant coffee has properly dissolved before adding any milk or water.

Using a coffee maker

an iced coffee in front of a coffee maker with milk at the side

(Image credit: GettyImages)

Coffee makers and espresso machines sometimes have an 'over ice' function. For example, the De'Longhi Dinamica will brew an over ice coffee at a slightly lower temperature so that it extracts a balanced and flavorful shot which can also offset any dilution that might happen from the ice. All you need to do is fill a glass with ice and press a button.

 I'd follow a similar method using an espresso machine like Breville's Barista Pro. You can adjust the settings to achieve a more concentrated, but mellow shot. Pull your shot into an espresso cup and then pour that gently over coffee ice cubes or normal ice. Then, you can dilute with cold water and milk to suit your own tastes.

Which coffee makers should I use?

The Dinamica and Barista Pro are well-geared towards iced coffee, but Nespresso's over ice pods would give brilliant flavors too. If you don't have a high-spec coffee maker, a French press or a drip coffee maker would do a brilliant job too. Don't leave your coffee to cool in your French press, because it will over-brew and become bitter, so make sure to pour it into another container. 

We asked Genevieve Kappler, Director of Coffee at Roasting Plant, what she would do with these coffee makers and she was full of helpful tips. She said 'when using a Chemex, try Ethiopian beans, because the method elevates their sweet, tropical fruit and delicate floral flavors. I personally like naturally processed coffees like Uganda Rwenzori or any deeply chocolatey, caramelley and spicy coffees that have fuller bodies. If you prepare your coffee in a French press, it will offer a more rich, deep, heavier mouthfeel'.

Director of Coffee
Genevieve Kappler
Director of Coffee
Genevieve Kappler

Genevieve Kappler has over 18 years of experience in the coffee industry. She has worked and studied everything about the process, from roasting right through to how the coffee tastes in your cup. She actively participates in the new sustainable model helping coffee roasters who are subject to price fluctuations.

Extra Tips

An affogato in a glass on a cork board with a wooden spoon

(Image credit: GettyImages)

When you serve iced coffee, I would always use a glass. That way, you can see as milk marbles into your black coffee. It looks really beautiful and, because your drink is cold, there's no need for it to be in a thick mug.

Maryna Gray from Bean Box gave us some extra tips for brewing the best iced coffee. She recommended using medium roast beans from Guatemala, El Salvador, Costa Rica, or Honduras. These will have sweet, creamy, and chocolatey flavor profiles, complementing your coffee drink. If that doesn't excite you, she recommends an Ethiopian or Kenyan roast, because they have 'refreshing tea-like fruit notes which shine through when poured over ice'.

If you want to get a little more creative, Ukrainian chef, Alex Kyiv, recommends a number of options. He told me that small amounts of flavored syrups can help to enhance the beans natural caramel, chocolate, and vanilla notes. 'For a healthier option, consider flavoring your coffee with spices like cinnamon or nutmeg'. If you wanted more subtle sweetness, non-dairy milks like almond, coconut, and oat milk are Alex's go-to option. He also says 'if you prefer your iced coffee sweet, consider using sweetened condensed milk for a creamy flavor, similar to Vietnamese iced coffee'. If you really want to celebrate, you could always add in a scoop of vanilla ice cream, affogato-style.

Michelle Conti, editor of My Morning Espresso, recommended using an accessory called the HyperChiller. To use it, you pour in hot water, let it sit for a few minutes, and pour it into your glass. You can add ice to keep it cool too. It's a great gadget if you want to make iced coffee quickly.

Food Blogger
Alex Bayev with his head back, smiling
Food Blogger
Alex Bayev

Alex is a food blogger, chef, and home expert from Ukraine. He's always testing unusual recipes and choosing the most efficient and creative methods to make delicious food and drink.


Can you just use hot coffee to make iced coffee?

Yes, it's a great way to use up any hot coffee that you don't want to drink. There are lots of methods which you could follow, but the most popular one requires you to pour your hot coffee into a glass pitcher filled with ice. This will melt the ice and dilute your coffee, so make sure that it's strong or that you use coffee ice cubes. When you're ready to drink the iced coffee, pour it into a new cup of ice and enjoy. You can add milks, syrups, and spices to flavor your brew too.

Do you have to let coffee cool to make iced coffee?

Ideally, yes. This will stop it from tasting overly bitter. However, Japanese iced coffee embraces the quick cool down, so you could brew drip coffee over ice, add a little milk for sweetness and enjoy an iced coffee without having to let it cool.

How do I make iced coffee from hot coffee without watering it down?

The best way is to use coffee ice cubes. Brew hot coffee, then pour it into an ice cube tray. When these melt in your coffee, they won't dilute your brew and will keep your flavor strong. Alternatively, you could make milk ice cubes to melt in your coffee, although these might curdle.

Can I make iced coffee with instant coffee?

You can make iced coffee from instant coffee, although it will make many coffee snobs shudder. I would brew a normal coffee, but with double the quantity of your usual instant coffee. Then, pour that coffee over ice. At this point, the ice will probably melt, so pour your cooled coffee back over another glass of ice and enjoy. 

If you're in a rush, another method is to throw instant coffee, ice, and a little water in a cocktail shaker and shake it all up. It doesn't taste amazing, but it's fast. 

Why does my iced coffee taste bitter?

If you are brewing your hot coffee directly onto ice, it might taste bitter. However, if your coffee is over or under extracted, it will also taste bitter. Make sure that you are using the right grind size, water that is not too hot, and the type of coffee beans that you like the taste of and then you might find that your coffee doesn't taste too bitter.

Why does my iced coffee taste bitter?

Coffee naturally balances sweetness, acidity, and bitterness. When your hot coffee is cooled using ice, it oxidises quicker, giving it a more acidic and bitter flavor profile. If you brew over ice directly, your coffee might also be diluted by the ice, which masks the delicate and aromatic notes of your beans in favor of the striking bitterness.

What is Japanese iced coffee?

Japanese iced coffee follows the flash brew method. Normally, a drip coffee maker will brew coffee directly over ice. This can be intense and might leave your coffee a little bitter tasting, but you can balance it by adding a little milk to your coffee.

What are the ingredients for iced coffee?

They're exactly the same as your normal coffee, just with ice cubes, or coffee ice cubes if you're prepared enough. You can add spices, syrups, and non-dairy milks to play with the flavor profiles too.

What's the difference between cold brew and iced coffee?

Hot coffee uses high temperatures and pressure to extract the coffee oils from the beans. When cooled and drunk as iced coffee, you'll taste a balance of acidic, bitter, and sweet notes. Cold brew is extracted at room temperature, so is a much slower process. The result is a concentrate which needs to be diluted. It's much sweeter and not acidic at all.

Is cold brew a good alternative to iced coffee?

It depends on what you want from your iced coffee. If you want a cool and caffeinated drink, cold brew is a great option. It’s sweeter and has more caramel notes in the aftertaste. If you really like the bitter balance of a hot coffee, keep making iced coffee from hot coffee.  

Can I just add cold water to coffee?

This is my go-to for making iced coffee in a hurry. I make an espresso, then dilute it with ice cold water. Once a couple of coffee ice cubes and in my glass with the coffee, it tastes like the perfect brew.

What's the fastest way to make iced coffee?

If you make hot coffee and pour it over ice, you'll have iced coffee almost instantly. We would recommend adding more ice to your coffee after it's been poured over ice, since most of the ice cubes will have melted. The danger with this super-quick method is that you water down your coffee and lose all the flavor. If you can pre-freeze coffee ice cubes, you'll solve this almost instantly.

What is the key making good iced coffee?

We asked Genevieve Kappler, Director of Coffee at Roasting Plant, the same question. She said 'buying fresh, just-roasted, whole bean coffee is always the better option. The reason why is that the flavor and the aroma are better protected from oxygen in the bean. Make sure not to over or under brew your coffee either.

Does iced coffee have more caffeine in?

You can make iced coffee from hot coffee, so the caffeine content is the same. If you use water ice cubes, you might have a more dilute cup, but that's the only reason why it might not taste as strong as your hot cup of joe.

Can I use pods to make iced coffee?

Yes. In the same way that you would use normal coffee, you can use coffee pods. Brands like Nespresso make special iced coffee pods which are tailored to taste less acidic and bitter when you brew them over ice.

Our Verdict

A French press pouring coffee over a kilner jar to make iced coffee

(Image credit: GettyImages)

If, like me, you're forever brewing too much coffee, this is a refreshing and alternative way to caffeinate and hydrate, especially when it's warm. Personally, I don't mind the bitterness from flash brewing, because I always add some almond or oat milk, which re-balances the flavor profiles. If I'm in a hurry, I tend to brew an espresso shot, then add cold water and a couple of coffee ice cubes. Replacing hot water with iced water cools the coffee at a slower rate than ice, but quick enough for me to enjoy it. If that's too bitter for you, I'd recommend trying cold brew.

Laura Honey
eCommerce Editor

Laura is our eCommerce editor. As a fully qualified barista, she's our expert in all things coffee and has tested over thirty of the best coffee makers on the market. She has also interviewed Q-Graders and world-leading experts in the coffee industry, so has an intimate knowledge of all things coffee. Before joining Homes & Gardens, she studied English at Oxford University. Whilst studying, she trained as a master perfumer and worked in the luxury fragrance industry for five years. Her collection of home fragrance is extensive and she's met and interviewed five of the world's finest perfumers (also known as 'noses'). As a result of this expansive fragrance knowledge, she always puts quality and style over quantity and fads. Laura looks for products which have been designed simply and with thoughtful finishes.