Cold Brew vs. Iced Coffee: What's the Difference?
Cold Brew vs. Iced Coffee: What's the Difference?
Walk into any coffee shop in summer and you'll see both cold brew and iced coffee on the menu. They might look similar, dark liquid, ice, maybe some milk, but they're made completely differently and taste nothing alike.
Walk into any coffee shop in summer and you'll see both cold brew and iced coffee on the menu. They might look similar, dark liquid, ice, maybe some milk, but they're made completely differently and taste nothing alike.
If you've ever wondered which one to order (or which one to make at home), here's the breakdown. The differences come down to extraction science, and understanding them helps you pick the one that fits your taste.

The Fundamental Difference: How They're Made
Let's start with the basics, because this is where everything else flows from.
Cold brew is made by steeping coarse coffee grounds in cold or room-temperature water for 12-24 hours. No heat involved at any point. You strain out the grounds and you've got cold brew concentrate. Iced coffee is regular hot-brewed coffee that's been cooled down and poured over ice. Sometimes it's brewed double-strength to account for ice dilution, but the extraction happens with hot water, just like your morning cup.
That single variable, extraction temperature, changes everything about the final drink.
What the Science Shows
According to research published in PMC, cold brew exhibits "differential extraction marked by decreased acidity, lower concentration of browned compounds, and fewer total dissolved solids" compared to hot brew.
Here's what that means in practice:
| Factor | Cold Brew | Iced Coffee (Hot Brewed) |
|---|---|---|
| Extraction time | 12-24 hours | 2-5 minutes |
| Water temperature | Room temp or cold | 90-96°C (195-205°F) |
| Total dissolved solids | 1.88-2.06% | 1.96-2.23% |
| Melanoidins (browned compounds) | Lower | Higher |
Interestingly, research from Scientific Reports found that caffeine and chlorogenic acid reach equilibrium between 6-7 hours of cold extraction, meaning the common recommendation of 12-24 hours may be more about convenience and flavor development than extraction efficiency.
Acidity: Why Cold Brew Tastes Smoother
This is the biggest practical difference most people notice.
You might expect cold brew to have a dramatically different pH, but research from Scientific Reports found that's not quite true:
| Method | pH Range |
|---|---|
| Cold brew | 4.96 - 5.13 |
| Hot brew | 4.85 - 5.10 |
So why does cold brew taste so much smoother? The answer is titratable acidity, the total amount of acid in the beverage, not just the hydrogen ion concentration that pH measures.
Hot brew samples required significantly more sodium hydroxide to neutralize, meaning they contain higher total acid content. Cold brew has fewer total acids, which explains why it tastes less sharp even though the pH readings are similar.
For people with sensitive stomachs or acid reflux, this distinction matters. Cold brew isn't just perceived as less acidic, it actually contains less total acid.
Caffeine Content: A Surprising Finding
You might have heard that cold brew has more caffeine. The truth is more nuanced.
Research from PMC found:
| Method | Caffeine Concentration |
|---|---|
| Cold brew (coarse grind) | 1,035-1,114 mg/L |
| Hot brew | 1,035-1,095 mg/L |
Cold brew with coarse grind actually showed slightly higher caffeine than hot brew. This happens because hot water extraction becomes diffusion-limited with larger particles, while cold brew's extended steeping time allows complete diffusion regardless of grind size.
But here's the practical reality: cold brew is often served as a concentrate, then diluted. Iced coffee is typically served at drinking strength. Depending on dilution, you could end up with similar caffeine per serving, or cold brew could have significantly more if you drink it concentrated.
Roast level matters too:
- Medium roast cold brew: ~1,205 mg/L caffeine
- Dark roast cold brew: ~1,035 mg/L caffeine
Medium roasts retain more caffeine because darker roasting degrades some caffeine compounds.
Flavor Differences: What You'll Actually Taste
The extraction temperature affects which compounds end up in your cup.
Research from PMC identified 94 volatile compounds in cold brew coffee, including furans, ketones, pyrazines, and various aromatics. But hot brewing extracts more of these volatile compounds overall.
Cold Brew Characteristics
- Sweeter, more pronounced natural sugars
- Fuller body with smoother mouthfeel
- Chocolate, caramel, and molasses notes
- Lower perceived acidity
- More mellow overall
- Fewer volatile aromatics (less "coffee smell")
Iced Coffee Characteristics
- Brighter, more pronounced acidity
- More aromatic complexity
- Fruity and floral notes come through
- Crisper, lighter body
- Tastes more like regular coffee, just cold
Neither is objectively better, they're genuinely different drinks. If you love the bright, aromatic qualities of hot coffee and just want it cold, iced coffee is your answer. If you want something smoother, sweeter, and less acidic, cold brew wins.

Health Considerations
Antioxidants
Here's something important from PMC/NIH research:
| Method | Antioxidant Capacity |
|---|---|
| Hot brew | 13.60-13.99 mmol Trolox/L |
| Cold brew | 10.13-13.09 mmol Trolox/L |
Hot brew consistently shows higher antioxidant capacity. The researchers noted that "lower antioxidant capacity in cold brew coffees may decrease the chemoprotective benefits known to be associated with hot brew coffees."
Interestingly, chlorogenic acid levels (a major coffee antioxidant) are similar between methods. This suggests hot brewing extracts additional bioactive compounds beyond chlorogenic acids.
Digestive Comfort
Cold brew's lower titratable acidity may cause less gastrointestinal irritation for some people. If regular coffee bothers your stomach, cold brew is worth trying.
Shelf Life and Storage
Cold brew has a significant advantage here.
According to research from PMC, refrigerated cold brew showed:
- No bacterial growth over 42 days of storage
- Superior flavor stability compared to hot brew
- Higher sweetness retention
- Slower off-flavor development
The primary limitation wasn't microbial, it was sensory. By day 42, all samples showed increased off-flavor scores.
Practical guidance:
- Cold brew concentrate: 1-2 weeks refrigerated
- Diluted cold brew: 3-4 days refrigerated
- Iced coffee: Best consumed same day (degrades quickly)
If you want to make coffee ahead for the week, cold brew is the clear choice.
How to Make Both at Home
Cold Brew
What you need:
- Coarse ground coffee
- Cold or room temperature water
- A container (jar, pitcher, French press)
- Something to strain (fine mesh + paper filter, or French press screen)
Method:
- Combine coffee and water at 1:8 ratio for concentrate (e.g., 100g coffee, 800g water)
- Stir to fully saturate grounds
- Cover and refrigerate 12-24 hours (or 14 hours for optimal flavor based on research)
- Strain through fine mesh, then paper filter for clarity
- Dilute concentrate 1:1 with water or milk when serving
Which Ember coffees work best: Medium to dark roasts. The smooth extraction complements chocolatey, nutty profiles and softens any roast character.
Iced Coffee
What you need:
- Your usual brewing setup (drip, pour over, AeroPress)
- Ice
- Optionally: brew double-strength
Method 1: Japanese-style (best quality)
- Brew pour over directly onto ice (use half your water volume as ice in the carafe)
- The hot coffee flash-chills, preserving aromatics
- Adjust brew ratio to account for ice dilution
Method 2: Simple
- Brew hot coffee at double strength
- Pour over a full glass of ice
- Ice dilutes it to normal drinking strength
Which Ember coffees work best: Light to medium roasts. The hot extraction brings out bright, fruity, floral notes that shine over ice.
Which Should You Choose?
| If you want... | Choose... |
|---|---|
| Smooth, sweet, low-acid | Cold brew |
| Bright, aromatic, crisp | Iced coffee |
| Make-ahead convenience | Cold brew |
| Fresher-tasting, same-day | Iced coffee |
| Maximum antioxidants | Iced coffee |
| Stomach-friendly option | Cold brew |
| Higher caffeine (potentially) | Cold brew concentrate |
Frequently Asked Questions
Is cold brew stronger than iced coffee?
It depends. Cold brew concentrate has high caffeine, but it's usually diluted before drinking. Straight cold brew concentrate can have significantly more caffeine than iced coffee. Diluted cold brew may have similar caffeine to iced coffee.
Why does cold brew cost more at coffee shops?
Time and coffee usage. Cold brew steeps for 12-24 hours (vs. 3 minutes for iced coffee) and typically uses more coffee per serving. The batch production and storage also add costs.
Can I heat up cold brew?
Yes, but it won't taste like hot-brewed coffee. Cold brew heated up remains smooth and low-acid, it just becomes warm cold brew. Some people prefer this, especially if they want lower acidity in a hot drink.
Does cold brew go bad?
Eventually. Concentrate lasts 1-2 weeks refrigerated, diluted cold brew lasts 3-4 days. You'll notice staleness (flat taste, off-flavors) before it becomes unsafe.
Which is better for sensitive stomachs?
Cold brew, generally. The lower titratable acidity means less total acid in your cup. If regular coffee causes discomfort, cold brew is worth trying.

The Bottom Line
Cold brew and iced coffee aren't interchangeable , they're genuinely different drinks made from the same ingredient. Cold brew is smooth, sweet, and mellow. Iced coffee is bright, aromatic, and crisp. Neither is better; they serve different preferences.
At Ember, our air-roasted beans work beautifully either way. The clean roasting profile means no burnt notes to muddy your cold brew, and the preserved origin characteristics shine in Japanese-style iced coffee. Try both and see which becomes your summer go-to.