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As the temperature soars and another heatwave settles over the UK, many of us will be reaching for iced coffee rather than a steaming mug. It's the obvious move when you're trying to cool down. But there's more going on in that frosted glass than simply "hot coffee, but cold" — the temperature at which coffee is brewed and the temperature at which you drink it both change the cup in ways that are genuinely worth understanding.
So before you throw some ice into this morning's leftover brew, let's talk about what's actually happening.
Brewed Cold vs. Drunk Cold: Two Different Things
The first thing worth clearing up is that "iced coffee" and "cold brew" are not the same drink, and the difference comes down to chemistry.
Iced coffee is brewed hot — espresso, filter, whatever you like — and then chilled, usually poured over ice. Cold brew never meets heat at all: coarsely ground coffee steeps in cold or room-temperature water for somewhere between 12 and 24 hours.
That single variable — heat during extraction — is responsible for nearly everything you taste in the final cup.
Why Heat Pulls More From the Bean
Hot water is a far more aggressive solvent than cold. When water is near boiling, it extracts compounds from coffee grounds quickly and thoroughly — the sugars, the fruity and floral aromatics, the bright acids, and yes, some of the bitter and astringent compounds too. This is why a well-made hot filter coffee can taste so vivid and layered: heat unlocks the full spectrum.
Cold water is choosier. It extracts much more slowly and simply can't dissolve certain compounds at all — particularly some of the acids and bitter elements that rely on heat to release. This is the key to cold brew's signature character:
What cold extraction gives you:
- Lower acidity — many of the acidic compounds that come through in hot brewing stay locked in the grounds, so cold brew tastes noticeably smoother and rounder.
- Lower perceived bitterness — the same goes for many bitter compounds, leaving a softer, sweeter cup.
- A heavier, syrupy body — the long steep time builds a rich, full mouthfeel.
- Muted brightness — the trade-off is that the delicate, sparkling top notes you'd get from a hot brew are largely absent.
None of this is better or worse — it's a different cup entirely. Cold brew trades complexity for smoothness. Hot-brewed-then-iced keeps the brightness but needs careful handling, which brings us to the next point.
The Dilution Problem (and How to Beat It)
Pour hot coffee straight over ice and you'll watch it melt, watering down your carefully brewed drink into something thin and disappointing. There are two reliable fixes.
Brew stronger to compensate. If you know the ice will dilute the cup, brew with a higher coffee-to-water ratio so the melt brings it back to balance rather than wrecking it. This is the principle behind "Japanese iced coffee" — brewing hot filter coffee directly onto ice, so it chills instantly while keeping all that aromatic brightness, with the recipe adjusted to account for the melt.
Use coffee ice cubes. Freeze leftover coffee into an ice tray and use those instead of water ice. As they melt, they only ever add more coffee to your glass. Simple, and effective.
Why Cold Coffee Tastes Different in Your Mouth
Here's the part most people never consider: even the exact same coffee tastes different cold than it does hot, before you've changed a single thing about how it's made.
Temperature directly affects how we perceive flavour. Our taste receptors and sense of smell are more responsive when food and drink are warm — which is why aromas lift off a hot cup and fill the room, and why a hot coffee tastes more intense. As coffee cools, those volatile aromatic compounds become far less active, so the nose of the drink quietens right down.
Cold also changes the balance of what we taste. Sweetness tends to read as more subdued when very cold, while bitterness can soften too. This is exactly why a coffee that tastes beautifully balanced hot might taste slightly flat over ice — and why coffees chosen specifically for iced drinking tend to be the ones with bold, sweet, chocolatey backbones that carry through the chill.
Which of Our Coffees Shine Over Ice
Because cold mutes the delicate high notes and softens sweetness, the coffees that perform best iced are the ones with naturally low acidity, real sweetness, and a chocolatey, full-bodied character. Two from our range are made for it.
Our Tamu Blend is the standout choice. Its name means "sweet" in Swahili, and that's exactly what it delivers — a velvety body, low acidity, and notes of milk chocolate, raisin and vanilla. That natural sweetness and smoothness are precisely the qualities that survive being served cold, making it a brilliant base for iced coffee or cold brew.
For a single origin, our Brazil Cerrado is another natural fit. Brazilian coffees are known for their low acidity and nutty, chocolatey depth — a profile that stays rich and satisfying even when the heat is gone.
If you'd rather browse the full range and find your own iced favourite, you'll find everything in our specialty coffee collection.
So this weekend, as you reach for something cold, you'll know exactly why it tastes the way it does — and how to make it taste even better. Brew strong, freeze your coffee cubes, and pick a bean with the body to carry the chill.
Stay cool out there.
