Brewing guide · 抽出
Cold Brew vs Iced Coffee: The Actual Difference
They look identical in the glass. They are not the same drink, and the difference is chemistry, not marketing.
Same glass, same ice, wildly different drinks. Iced coffee is hot coffee that got cold. Cold brew was never hot. That one distinction — temperature during extraction — cascades into everything you taste.
How each is made
Iced coffee is brewed hot (drip, pour-over, espresso), then chilled or poured over ice. Total brew time: minutes. Often brewed double-strength so the ice melt doesn't drown it.
Cold brew steeps coarse grounds in cold water for 12–24 hours (full method here), then gets strained and served without heat ever entering the process.
Why they taste different
Hot water is an aggressive solvent: it extracts quickly and it extracts almost everything — the sugars, the acids, and the volatile aromatics that make hot coffee smell the way it does. Cold water is selective. Over a long steep it pulls the sweet, chocolatey, low-acid material efficiently while leaving a larger share of the sharper acids and some aromatic compounds in the grounds.
The practical result:
- Cold brew — smoother, sweeter-reading, heavier body, muted aroma, chocolate-and-nut flavors forward, noticeably lower perceived acidity.
- Iced coffee — brighter, more acidic, more aromatic, lighter body; it keeps more of the bean's origin character, along with more of its bite.
Neither is objectively better. Cold brew flatters big, roasty, comfortable coffee. Iced coffee flatters expensive, fruity, interesting coffee. Match the method to the bean — the beans guide goes deeper.
The caffeine question, honestly
"Cold brew has more caffeine" is half true. Per ounce, cold brew concentrate carries far more caffeine — because it's concentrate. Diluted to drinking strength, the numbers land in the same neighborhood as strong iced coffee. Cold brew usually wins in practice only because cafés serve it stronger than they serve iced coffee, not because cold water performs caffeine magic. The full numbers are in the caffeine guide.
The third option nobody orders
Japanese iced coffee — flash brew — is pour-over brewed hot directly onto a bed of ice, so it chills the instant it's extracted. You get hot-brew aromatics and brightness with none of the stale, hours-old-pot character of most café iced coffee. It's the best of both methods, it takes four minutes, and it remains criminally under-served.
Given this site's whole identity descends from Japanese slow-drip mizudashi — the original cold brew, dripping away in kissaten long before nitro taps existed — we have a soft spot for Japan's other cold coffee invention too. You'll meet both in the city reviews.
Which should you drink?
- You want smooth, strong, and make-ahead: cold brew. Batch it Sunday, drink it all week.
- You bought a $22 bag of Ethiopian: Japanese iced coffee. Let the bean talk.
- You want café iced coffee: make flash brew at home and stop paying $6 for yesterday's drip over ice.