What is the 15-15-15 coffee rule?

I’ve seen the 15-15-15 coffee rule mentioned a few times in wellness circles and productivity hacks, but I’m confused about what it actually means. Does it refer to a specific brewing method, a way to time your coffee intake for maximum energy without crashes, or something else entirely? I’m particularly interested because I’m always looking for ways to optimize my morning routine and avoid the afternoon slump. Could you break down exactly what the 15-15-15 rule entails in terms of coffee consumption, any preparation steps, or timing involved?

The 15-15-15 coffee rule is a brewing technique, particularly common for pour-over methods like the Hario V60, designed to achieve consistent extraction by regulating pouring speed and timing. It involves a structured approach to water addition:

1. First Pour (Bloom): Pour water equal to twice the weight of the coffee grounds (e.g., 40g water for 20g coffee) in 15 seconds. This saturates the grounds, allowing gases to escape. After pouring, wait 30 seconds to complete the bloom.
2. Second Pour: Over the next 15 seconds, pour the remaining water in a steady spiral motion, moving from the center outward and back. Aim to keep the water level just above the coffee bed.
3. Total Brew Time: The entire process (from first pour to draining completion) should take approximately 2:30 to 3 minutes per 100g of coffee grounds. The "15-15-15" emphasizes the strict 15-second intervals for pours and a 30-second bloom rest, ensuring controlled extraction.

This method enhances uniformity by:

• Preventing channeling by maintaining consistent saturation.
• Optimizing extraction under 3 minutes for balanced acidity, body, and sweetness.
• Adjusting water temperature to 90–96°C (194–205°F) for ideal solubility.

Grind size should be medium-fine (similar to table salt). Ratios typically use 1:15 coffee-to-water (e.g., 20g coffee to 300g water), but ratios can vary based on preference. The rule is adaptable but foundational for precision in pour-over brewing.