Cold Brew Coffee Ratio Calculator

How This Tool Works

This calculator helps you determine the exact coffee:water ratio for cold brew based on your preferred strength. Cold brew coffee is made by steeping coarsely ground coffee in cold or room temperature water for an extended period (typically 12-24 hours). Unlike hot brewing methods, cold brew extracts flavors more slowly and produces a smoother, less acidic coffee concentrate.

The calculator uses standard cold brew ratios that have been tested by coffee professionals. It calculates the precise water amount needed based on your coffee quantity and desired strength, then provides recommended steeping times to ensure optimal extraction without over-extraction that can lead to bitterness.

Formula

The water amount is calculated using:

Water (g) = Coffee (g) × Ratio

Ratios by strength:

• Weak: 1:12 (1 gram coffee per 12 grams water)
• Normal: 1:10 (1 gram coffee per 10 grams water)
• Strong: 1:8 (1 gram coffee per 8 grams water)

Examples

• 50g coffee, Normal strength: 500g water, 16-20 hours steeping
• 75g coffee, Strong strength: 600g water, 18-24 hours steeping
• 40g coffee, Weak strength: 480g water, 12-16 hours steeping
• 100g coffee, Normal strength: 1000g (1L) water, perfect for making concentrate

Cold Brew Tips & Best Practices

• Grind Size: Use coarsely ground coffee (similar to sea salt) to prevent over-extraction and sediment
• Water Quality: Use filtered water for the best flavor - tap water impurities can affect taste
• Steeping Location: Room temperature (18-22°C) is ideal, but refrigerator steeping works too (takes longer)
• Stirring: Gently stir the coffee and water mixture after combining to ensure even saturation
• Straining: Use a fine mesh strainer or cheesecloth, and consider double-straining for cleaner concentrate
• Storage: Cold brew concentrate keeps well in the refrigerator for up to 2 weeks
• Serving: Dilute concentrate 1:1 or 1:2 with water, milk, or your preferred liquid
• Ice: Cold brew is less diluted by ice than hot coffee, making it perfect for iced drinks

FAQ

• What is the best ratio for cold brew coffee?
  The best ratio depends on your preference and how you plan to serve it. A 1:10 ratio (normal strength) is most common and produces a balanced cold brew that works well as a concentrate. For stronger coffee that you'll dilute more, use 1:8. For milder coffee or if you plan to drink it straight, use 1:12. Many coffee shops use 1:8 for their concentrate, which they then dilute 1:1 or 1:2 when serving.
• How long should I steep cold brew?
  Cold brew typically needs 16-20 hours of steeping at room temperature (18-22°C). If steeping in the refrigerator, add 2-4 hours. Stronger brews (1:8 ratio) may benefit from 18-24 hours for full extraction. Weaker brews (1:12) can be ready in 12-16 hours. Steeping too long (over 24 hours) can lead to over-extraction and bitterness, while too short (under 12 hours) may result in weak, under-extracted coffee.
• Can I use this ratio for hot coffee?
  No, these ratios are specifically designed for cold brew extraction. Hot coffee typically uses different ratios (around 1:15 to 1:17 for drip coffee, 1:12 to 1:15 for French press) because hot water extracts coffee compounds much more efficiently. Using cold brew ratios for hot coffee would produce extremely strong, over-extracted coffee.
• Should I use whole beans or pre-ground coffee?
  For best results, grind whole beans just before brewing. Use a coarse grind (similar to sea salt or breadcrumbs) - too fine will create sediment and over-extraction. If using pre-ground, choose a coarse grind specifically labeled for cold brew or French press. Freshly ground coffee produces better flavor, but pre-ground works if stored properly.
• Can I make cold brew with decaf coffee?
  Yes, decaf coffee works perfectly for cold brew using the same ratios. The cold brewing process works the same way regardless of caffeine content. Decaf cold brew can be a great option for evening drinks or for those sensitive to caffeine.
• How should I store cold brew concentrate?
  Store cold brew concentrate in an airtight container in the refrigerator for up to 2 weeks. The concentrate stays fresh longer than brewed coffee because the cold extraction process produces fewer volatile compounds. Always use clean containers and utensils to prevent contamination. If you notice any off flavors or cloudiness, discard the concentrate.