If you’re new to making cold brew at home, your first question is probably how much coffee for cold brew you need. It’s the key to getting that smooth, strong, and low-acidity concentrate everyone loves, without any guesswork.
Getting the ratio right makes all the difference. Too much coffee and it can become bitter or a waste of good beans. Too little and you’ll end up with a weak, watery drink that doesn’t taste like much. Let’s break down the simple math and methods so you can make perfect cold brew every single time.
How Much Coffee For Cold Brew
The standard, most reliable starting point for cold brew coffee is a 1:4 coffee-to-water ratio for concentrate, or a 1:8 ratio for a ready-to-drink brew. This means for every 1 cup of coarsely ground coffee, you use 4 cups of cold water to make a concentrate, or 8 cups of water for a brew you can drink straight.
We measure this by weight for absolute accuracy. Volume measurements (like using cups) can vary a lot because grind size affects how much space coffee takes up. Using a kitchen scale is the best way to ensure consistency.
Why the Coffee-to-Water Ratio is Everything
Cold brew is an immersion method. Coffee grounds steep in cold water for a long time, usually 12-24 hours. Unlike hot brewing, the cold water extracts flavors slowly and selectively.
This process pulls out the sweet, chocolaty, and nutty notes from the coffee, while leaving behind most of the acidic and bitter compounds that hot water grabs quickly. The ratio controls the strength and balance of this extraction.
- Concentrate Ratio (1:4 to 1:5): This yields a super-strong brew meant to be diluted with water, milk, or ice. It’s versatile and stores well in the fridge for up to two weeks.
- Ready-to-Drink Ratio (1:8 to 1:10): This makes a brew you can pour directly over ice. It’s less economical and has a shorter fridge life, but it’s super convenient.
Measuring by Weight vs. Volume
Let’s get specific. A “cup” of coffee can mean very different things. A volume-based “cup” of whole beans is not the same as a “cup” of finely ground coffee, which is not the same as a “cup” of the coarse grind you need for cold brew.
Weight doesn’t lie. Here’s the simple conversion:
- 1 part coffee = 1 ounce (28 grams) of coffee beans
- 4 parts water = 4 fluid ounces (118 ml) of water
So, a classic 1:4 concentrate recipe is actually: 4 ounces (112g) of coffee to 16 fluid ounces (473ml) of water. This makes about 16oz of concentrate, which becomes 32oz of delicious drink after diluting.
Sample Batch Sizes by Weight
Here are some easy batch sizes to follow using a kitchen scale:
- Small Batch (Makes ~24oz drinkable coffee): 3 oz (85g) coffee + 12 oz (355ml) water (1:4 ratio). Dilute with 12 oz water.
- Medium Batch (Makes ~32oz concentrate): 8 oz (225g) coffee + 32 oz (946ml) water (1:4 ratio).
- Large Batch (Makes ~64oz drinkable coffee): 6 oz (170g) coffee + 48 oz (1.4L) water (1:8 ready-to-drink ratio).
Choosing Your Coffee Beans
The amount you use is crucial, but so is the coffee itself. Since cold brew highlights a coffee’s inherent sweetness and body, the bean choice matters.
- Roast Level: Medium to dark roasts are most popular. They give those classic chocolate, caramel, and nutty notes. Light roasts can be used, but they might taste more tea-like and less bold.
- Grind Size: This is non-negotiable. You must use a coarse grind. It should look like sea salt or rough breadcrumbs. A fine grind will over-extract, making the brew muddy and bitter, and it’s very hard to filter out.
- Freshness: Use beans roasted within the last 2-4 weeks for the best flavor. Stale beans make flat, dull cold brew.
The Step-by-Step Cold Brew Method
Now that you know how much coffee for cold brew to use, let’s put it into practice. The process is remarkably simple.
Equipment You’ll Need
- A large jar, pitcher, or dedicated cold brew maker (like a Toddy system)
- Kitchen scale (highly recommended)
- Burr grinder (for a consistent coarse grind)
- Fine-mesh sieve, nut milk bag, or cheesecloth for filtering
- A separate carafe or bottle for storing the finished brew
Step-by-Step Instructions
- Weigh and Grind: Measure your chosen amount of coffee beans by weight. Grind them coarsely.
- Combine: Add the coarse grounds to your brewing container. Pour in the measured amount of cold, filtered water.
- Stir: Gently stir the mixture to ensure all grounds are fully saturated. This prevents dry clumps.
- Steep: Cover the container and let it sit at room temperature or in the refrigerator for 12-24 hours. Room temp yields a slightly faster, fuller extraction; the fridge results in a slightly cleaner taste.
- Filter: Place your filter (sieve lined with cheesecloth, a nut milk bag, etc.) over your storage carafe. Slowly pour the steeped mixture through to separate the grounds. You may need to do this in batches. Avoid squeezing the filter, as it can push bitter sediments through.
- Store and Serve: Seal the finished cold brew concentrate in a clean bottle or jar. It keeps in the refrigerator for up to 2 weeks. To serve, dilute concentrate with an equal part water, milk, or your favorite mixer over ice. Ready-to-drink brew can be poured straight.
Troubleshooting Your Batch
Did something not go quite right? Here’s how to fix common problems:
- Too weak or watery: Use a higher coffee-to-water ratio next time (e.g., move from 1:8 to 1:6 for ready-to-drink). Or, steep for longer, up to 24 hours.
- Too strong or bitter: Dilute it more when serving. Next batch, use a little less coffee or a slightly shorter steep time. Also, double-check your grind isn’t too fine.
- Cloudy or muddy: Your filtration wasn’t fine enough. Use a paper filter in addition to your mesh sieve, or filter it twice. A too-fine grind can also cause this.
- Sour or funky taste: This often means it didn’t steep long enough, or your water was too cold (if brewed in the fridge). Try a room-temperature steep for 18 hours.
Advanced Tips & Flavor Variations
Once you’ve mastered the basic ratio and method, you can start to experiment. The great thing about knowing the foundational “how much coffee for cold brew” rule is that you can scale and adapt it confidently.
Scaling Up for a Crowd
Hosting a brunch or just love having plenty on hand? The math scales linearly. For a big batch of concentrate using a 1:5 ratio:
- 1 pound (16 oz / 454g) of coffee + 80 fluid ounces (2.36L) of water.
- This will yield about 80 oz of concentrate, which becomes 160 oz of served coffee—plenty for a party.
Flavoring Your Cold Brew
Add flavor during the steeping process or after. Here’s a few ideas:
- Spices: Add a few cinnamon sticks, whole cloves, or cardamom pods to the grounds before adding water.
- Vanilla: Add 1-2 split vanilla beans or a teaspoon of vanilla bean paste to the mix.
- Chocolate: Mix in a 1/4 cup of cacao nibs with your coffee grounds.
- Citrus Zest: A few strips of orange or lemon zest can add a bright note (remove after steeping).
Remember, when adding solids, you’ll need to filter them out along with the coffee grounds, so use large pieces for easy removal.
Dilution and Serving Ideas
The classic dilution for concentrate is 1:1 with water or milk. But don’t stop there:
- Over Ice: The ice will melt and dilute it perfectly. Use larger ice cubes to melt slower.
- With Fizz: Dilute with sparkling water or tonic water for a refreshing spritz.
- Creamy Version: Use oat milk, almond milk, or classic cream. A splash of sweetened condensed milk makes a decadent treat.
- In Cocktails: Use cold brew concentrate as a base for coffee cocktails instead of espresso.
Frequently Asked Questions (FAQ)
How fine should I grind coffee for cold brew?
Always use a coarse grind, similar to raw sugar or breadcrumbs. A fine grind will over-extract and make filtering nearly impossible, resulting in a bitter and muddy brew.
Can I use pre-ground coffee for cold brew?
You can, but make sure it’s labeled for “cold brew” or “French press,” which indicates a coarser grind. Pre-ground for drip machines is often too fine. For the best flavor, grinding fresh beans right before brewing is always superior.
How long does homemade cold brew last?
When stored in a sealed container in the refrigerator, cold brew concentrate stays fresh for up to 2 weeks. Ready-to-drink cold brew (a weaker ratio) is best consumed within 5-7 days. If it starts to smell or taste off, it’s time to make a new batch.
Do I need a special cold brew maker?
No, you don’t. A large mason jar and a fine mesh filter or nut milk bag works perfectly well. Dedicated cold brew makers can simplify filtering, but they aren’t a requirement for great results at home.
Why is my cold brew bitter?
Bitterness usually comes from over-extraction. The main culprits are: 1) Grind is too fine, 2) Steep time was too long (over 24 hours), or 3) The coffee-to-water ratio had to much coffee for the amount of water. Try adjusting one of these factors next time.
What’s the difference between cold brew and iced coffee?
They are completely different. Iced coffee is hot-brewed coffee (like drip or pour-over) that is then cooled and poured over ice. Cold brew is never heated; it’s steeped in cold water for many hours. Cold brew is naturally sweeter, smoother, and less acidic than iced coffee.
Can I make cold brew with hot water first?
That would not be cold brew. Starting with hot water changes the extraction process fundamentally, pulling out more acids. The defining feature of cold brew is its slow, cold extraction, which gives it it’s unique flavor profile.
Mastering your homemade cold brew truly comes down to nailing that initial measurement. Once you have your preferred ratio locked in—whether it’s a strong 1:4 concentrate or a mellow 1:8 ready-to-drink brew—you can make cafe-quality coffee anytime. Remember to use a scale if you can, always grind coarse, and don’t be afraid to tweak the steep time or dilution to match your personal taste. With these guidelines, you’ll never have to wonder about how much coffee for cold brew again.