The Zero Ratio: 2g Per Ounce
Standard · 5 min read
2 grams of coffee per ounce of water. Every time. That number is the foundation. Everything else in brewing gets built on top of it.
Most people brew by feel. Some water, some coffee, "that looks about right." The result is inconsistent. Some cups are strong, some are weak, all of them vary. You can't improve what you can't measure, and you can't measure without a standard.
2g per ounce is the professional standard. It's what specialty coffee roasters aim for, what competition brewers use, and what produces a consistently balanced extraction across different brewing methods, roast levels, and equipment.
Why This Specific Ratio
Coffee extraction is a chemistry problem. The goal is to dissolve the right amount of soluble compounds from the grounds into the water. Too little coffee (under-dosing) and you don't have enough flavor compounds to extract — the cup tastes thin and sour. Too much coffee (over-dosing) and the water can't dissolve all of it — the cup tastes harsh and heavy.
2g per ounce is the ratio that balances these two extremes. It's been tested, refined, and proven across thousands of brews. It's not a suggestion. It's a standard.
What "balanced extraction" means: In a properly extracted cup, the water has dissolved roughly 18–22% of the soluble compounds from the coffee. Below 18% is under-extraction (sour, thin). Above 22% is over-extraction (bitter, harsh). The 2g per ounce ratio puts you in that sweet zone consistently.
How to Use It
With a scale — the right way:
Weigh your water. Multiply by 2. That's your coffee amount in grams. If you're brewing 12 ounces of water, use 24 grams of coffee. Set a timer. Brew. Done.
Without a scale — the practical way:
A standard coffee scoop is roughly 10 grams. For every 5 ounces of water, use one heaping scoop. 10 ounces = 2 scoops. 15 ounces = 3 scoops. Not as precise as a scale, but close enough to stay in the ballpark.
Does It Change by Brewing Method?
No. The ratio stays the same. What changes is the water volume. For immersion brewing (French press, cold brew, cupping), you brew directly in the final volume. For drip brewing (pour-over, automatic drip), you brew and the water passes through. In both cases: 2g coffee per ounce of final water.
The grind size, brewing temperature, and brew time adjust to the method. The ratio doesn't.
FAQ
Is 2g per ounce the only ratio that works?
It's the professional standard that produces consistent, balanced results. You can brew stronger (3g per ounce) or weaker (1.5g per ounce), but you move outside the balanced extraction zone. Once you've brewed at the standard, you'll notice the difference immediately in any deviation.
Do I need a scale to brew correctly?
A scale makes it precise. Without a scale, you can approximate using scoops and get results close enough to be consistent. But once you've brewed at the standard with a scale, you'll notice that approximation isn't quite the same.
What if my coffee tastes wrong even at the right ratio?
Check temperature next. The ratio handles the amount — temperature handles the extraction rate. If the ratio is right but the cup tastes under-extracted (sour), raise water temperature. If over-extracted (bitter), lower it.