Both methods brew coffee with cold water, and both avoid the harshness that heat pulls out. The difference is contact: cold brew soaks the grounds for hours, cold drip runs cold water through them one drop at a time.
How cold drip works
A drip tower is three chambers stacked vertically. Iced water sits at the top, a bed of ground coffee in the middle, a collection vessel at the bottom. A valve is set so the water releases at roughly one drop per second, and it percolates through the bed under gravity alone.
A full tower takes somewhere between three and twelve hours depending on the drip rate and the volume. Because the water is always fresh as it passes through, extraction is more even than in a steep, and the result is cleaner and more tea-like, with the acidity and the aromatics intact.
Cold drip vs cold brew
- Cold brew (immersion): grounds sit in cold water 12 to 24 hours, then are filtered out. Heavier, rounder, chocolatey, low acidity. Very forgiving.
- Cold drip (percolation): water passes through over hours. Lighter, brighter, more delicate and more aromatic. Less forgiving, because the drip rate and the bed matter.
Neither is better. Cold brew suits milk and big chocolatey blends. Cold drip suits a good single origin you want to actually taste.
Ratios and grind
Start around 60g of coffee per litre of water for a drinkable strength, or up to 100g per litre if you want a concentrate to dilute. Grind medium, roughly filter grind: too fine and the bed clogs and the drip stalls, too coarse and the water falls straight through and under extracts.
Wet the bed evenly before you start the drip, or the water will carve a channel and run through the same path for hours. The full sizing is in the coffee grind size chart.
Which beans
Cold drip rewards clarity, so this is the place for a light or medium single origin with fruit or florals, the kind of coffee that tastes thin through milk. Dark roasts turn flat and slightly ashy.
If you do not want to own a tower
Towers are beautiful and slow, and most people want cold coffee on a Tuesday rather than a project. A ready made concentrate gives you the cold coffee without the six hour wait: dilute with water or milk, over ice.
Storing it
Cold drip is best within about three days, kept sealed in the fridge. It is more delicate than cold brew and its aromatics fade faster, which is the trade for that clarity. For the immersion method step by step, see how to make cold brew coffee.
