What Is Cold Brew Coffee? ☕
Cold brew is coffee prepared with room-temperature or cold water instead of hot water, requiring a steeping time of 12 to 24 hours (ideally 16 hours). The result is a smooth, concentrated coffee that can be stored in the fridge for up to two weeks and diluted with water or milk before serving.
What Is the Best Ratio for Cold Brew Coffee?
The recommended coffee-to-water ratio for cold brew is 1:5. This is a mass-to-volume relationship: 1 gram of coffee grounds per 5 ml of water. This calculator supports three strength levels:
- Light: 1:5.6 — mild, less caffeine, gentle flavour
- Regular: 1:5.3 — balanced concentrate, the most popular choice
- Strong: 1:5 — intense concentrate, great for recipes and milk drinks
How to Calculate Cold Brew Coffee Quantities
Because coffee grounds absorb approximately 20% of the water during steeping, the final volume of concentrate is about 80% of the initial water volume. The formulas are:
-
Required water volume = Desired concentrate volume ÷ 0.8
Example: to obtain 250 ml of concentrate → 250 ÷ 0.8 = 312.5 ml of water -
Required coffee mass (g) = Required water volume (ml) ÷ Ratio
Example (regular 1:5.3): 312.5 ÷ 5.3 ≈ 59 g of ground coffee
The cold brew ratio calculator handles all these steps automatically and shows results in both metric (ml / g) and American (cups / fl oz / oz) units.
Cold Brew vs. Hot Coffee
| Property | Cold Brew | Hot Drip Coffee |
|---|---|---|
| Coffee-to-water ratio | 1:5 – 1:5.6 | 1:15 – 1:17 |
| Brewing temperature | Room temp / fridge | 90–96 °C (195–205 °F) |
| Brewing time | 12–24 hours | 3–5 minutes |
| Acidity | Lower | Higher |
| Shelf life | Up to 2 weeks (fridge) | Best fresh |
| Caffeine (per serving) | Higher (concentrated) | Standard |
How Much Caffeine Is in Cold Brew?
Because cold brew uses a higher coffee-to-water ratio (1:5 vs. 1:17 for hot drip), the concentrate itself contains significantly more caffeine. A typical 240 ml (8 fl oz) serving of undiluted cold brew concentrate can contain 150–250 mg of caffeine, compared to roughly 95 mg in a regular cup of hot coffee.
However, cold brew is usually diluted 1:1 with water or milk before drinking, which brings caffeine levels closer to those of standard hot coffee.
Is Cold Brew Less Acidic Than Regular Coffee?
Yes. Because cold water extracts fewer acidic compounds than hot water, cold brew is generally 60–70% less acidic than hot drip coffee. This makes it a popular choice for people with sensitive stomachs or acid reflux.
Frequently Asked Questions
- Can I make cold brew in a regular jar?
- Yes — any glass jar or pitcher with a lid works. Just add coffee grounds and water, stir, cover, and steep in the fridge.
- How coarse should the grind be?
- Use a coarse grind (similar to sea salt). Fine grounds can make the brew over-extracted and bitter, and they clog filters.
- Should I steep in the fridge or at room temperature?
- Both work. Room temperature: 12–14 hours. Refrigerator: 18–24 hours. The fridge method produces a cleaner, slightly milder flavour.
- How do I dilute cold brew concentrate?
- A common ratio is 1 part concentrate : 1 part water or milk. Adjust to your taste.
- Can I use cold brew concentrate in recipes?
- Absolutely. Cold brew concentrate is excellent in coffee ice cream, tiramisu, smoothies, and cocktails.
- Does temperature affect caffeine extraction?
- Cold water extracts caffeine more slowly, which is why cold brew needs many hours. The final caffeine content depends mainly on the coffee-to-water ratio and steep time.