Brew Scaling Tool
Take a recipe you already like and scale it for a crowd. It splits the job into brews your brewer can actually hold, with the timing and grind to match.
6 cups of about 220 ml at 1:16.7
2 brews in a V60 03
- Coffee per brew
- 45 g
- Water per brew
- 750 g
- Brew time
- about 5:15
In total: 90 g of coffee and 1.5 kg of water.
- The bed is deeper than your usual brew, so grind a notch coarser to keep the drawdown on time.
- Start the next brew as the last one drains, and pool them in an insulated server at 80–85 °C rather than on a hot plate.
How it works
Scaling coffee is more than multiplying everything blindly. This tool preserves brew ratio and gives you a realistic time adjustment so larger brews stay balanced.
- Keep your coffee-to-water ratio consistent at any batch size.
- Avoid weak party batches caused by under-dosing.
- Use time guidance that scales more realistically than a straight multiplier.
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Enter the recipe that already tastes good
Start from a brew you trust rather than inventing a large-batch recipe from scratch.
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Set the new serving count
The tool recalculates dose, water, and an adjusted brew time for the larger or smaller batch.
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Brew and make a final taste adjustment
Large brews can still need a minor grind tweak because bed depth and pour dynamics change.
Questions
Why does brew time not scale in a straight line?
As batch size grows, bed depth, drawdown resistance, and thermal mass change. A square-root style time adjustment is often a better starting point than doubling brew time outright.
Should I change grind size when scaling up?
Sometimes. If larger batches stall or taste heavy, go a little coarser. If they run fast and thin, go a little finer.
Does brew scaling work for cold brew and immersion recipes too?
Yes, but very large immersion batches may still need small tweaks because agitation, vessel shape, and thermal retention change as batch size grows.
Why do big batches often taste duller than single cups?
Larger brews can lose clarity when temperature, pouring, and bed depth become less controlled, so scaling the recipe is only part of the fix.