September 28, 2023

Coffee Ordering

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A barista’s guide on how to make iced coffee from hot coffee

A barista’s guide on how to make iced coffee from hot coffee

how to make iced coffee from hot coffee: a glass of iced coffee being poured over ice

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.

What is iced coffee?

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

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

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

A black iced coffee on a marble countertop

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

an iced coffee on a wooden countertop

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.

Flash Brew

A drip coffee maker brewing iced coffee on a table

A drip coffee maker brewing iced coffee on a table

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.

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.

Quick espresso method

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

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

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

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

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.

De’Longhi Dinamica Plus Coffee Maker: Brad Pitt’s choice

The Dinamica is a dynamic coffee maker, with over 16 different coffee settings, a brilliant milk frother, and premium finishes. The over ice option adds an extra level to this machine’s capabilities. Rather than producing a normal shot, it anticipates how your coffee will change over ice.

Breville Barista Pro: our barista’s favorite espresso maker

An expert espresso machine for professional, barista-quality coffee making, this machine is hard to fault. The adjustable settings mean that you can pull the perfect espresso shot over ice without it turning bitter.

Nespresso Vertuo Next coffee maker review – premium coffee, made easy

An easy option for coffee lovers, Nespresso have launched special pods for iced coffee, so you can enjoy a cold brew without any bitter or acidic flavors. Simply put a pod in, press a button, and you’re ready to go.

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.

Espro P7 French Press

Espro’s French press is an investment. It’s more expensive than average, but the stainless steel, double walled, double filter mechanisms means that you’ll brew a smooth and aromatic coffee, perfect for icing.



Chemex Pour Over Coffee Maker

We love the Chemex coffee maker, especially for iced coffee. The glass carafe means that you can slow cool your coffee in the same container that it was brewed in. That’s less washing up and a delicious coffee too.



Extra Tips

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

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

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.


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?

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.

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.

Our Verdict

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

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

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.