1 Gallon Cold Brew: How Much Coffee Grounds? - The Best Coffee Machine Blog

Quick answer

For a 1-gallon batch of cold brew, aim for a 1:4 coffee-to-water ratio by weight.
This typically means around 16 oz (about 2 cups) of whole beans.
Grind your beans coarsely, like coarse sea salt.
Use filtered water. It makes a difference.
Let it steep for 12-24 hours. Longer steeps mean stronger brew.
Strain it well. Nobody likes sludge.
Adjust to your taste. It’s your coffee, after all.

Who this is for

You’re looking to make a big batch of cold brew to last a few days.
You want a smoother, less acidic coffee experience.
You’re ready to ditch the pricey store-bought stuff and brew your own.

What to check first

Brewer type and filter type

Cold brew is pretty forgiving. You can use a French press, a large mason jar with a cheesecloth, or a dedicated cold brew maker. The main thing is you need a way to steep the grounds and then separate them from the liquid. If you’re using a French press, the built-in filter is your go-to. For jars, cheesecloth or a fine-mesh sieve will work. Just make sure your filter is fine enough to catch most of the grounds.

Water quality and temperature

Tap water can have off-flavors that mess with your coffee. Filtered water is your best bet for a clean taste. You don’t need fancy equipment, just a pitcher filter will do. For cold brew, the temperature is literally in the name: cold. Room temperature or refrigerated water is perfect. No need to heat anything up.

Grind size and coffee freshness

This is crucial for cold brew. You want a coarse grind, think coarse sea salt or breadcrumbs. Too fine, and you’ll get a muddy, over-extracted mess. Too coarse, and it might be too weak. Freshly roasted beans are always best. Look for a roast date on the bag. Grind them right before you brew for maximum flavor.

Coffee-to-water ratio

This is where the magic happens. For a strong concentrate, a 1:4 ratio (coffee to water) by weight is a solid starting point. For a 1-gallon batch, which is 128 oz of water, that’s about 32 oz of coffee by weight. That’s a lot of beans! Many people prefer a slightly less concentrated brew, like 1:5 or 1:6, especially if they plan to dilute it with water or milk. For a 1-gallon batch (128 oz water), a 1:5 ratio would be about 25.6 oz of coffee by weight. A 1:6 ratio would be about 21.3 oz of coffee by weight. I usually start with around 16 oz of whole beans for a 1-gallon batch, which gives me a nice concentrate that I can dilute to my liking. That’s roughly a 1:8 ratio if I use all 128 oz of water, but I often end up using less water to steep, making it more concentrated. It’s all about finding your sweet spot.

Cleanliness/descale status

This one’s easy. Wash your gear. Seriously. Old coffee oils can go rancid and make your fresh brew taste like old gym socks. Rinse your brewer, containers, and filters thoroughly after each use. If you have a machine with heating elements or complex parts, check the manual for descaling instructions. For simple cold brew setups, a good wash with soap and water is usually enough.

Step-by-step (brew workflow)

1. Weigh your beans.

What “good” looks like: You have a precise amount of whole beans ready to go. For a 1-gallon batch, start with around 16 oz of whole beans by weight.
Common mistake: Guessing the amount. This leads to inconsistent results. Use a kitchen scale.

2. Grind your coffee beans.

What “good” looks like: A coarse, even grind resembling coarse sea salt.
Common mistake: Grinding too fine. This makes your cold brew bitter and sludgy. Use a burr grinder if possible and set it to its coarsest setting.

3. Measure your water.

What “good” looks like: You have your cold, filtered water measured out. For a 1-gallon batch, you’ll need about 128 oz of water. You might not use it all in the initial steep, depending on your setup and desired concentration.
Common mistake: Using tap water. It can impart off-flavors. Stick to filtered water.

4. Combine coffee and water.

What “good” looks like: The coarse grounds are fully saturated with water. Gently stir to ensure all grounds are wet.
Common mistake: Not saturating all the grounds. This leads to uneven extraction. Give it a good stir.

5. Steep.

What “good” looks like: Your mixture is covered and sitting in a cool, dark place (like your fridge or pantry) for 12-24 hours.
Common mistake: Leaving it out on the counter. This can lead to bacterial growth and a less-than-ideal taste. Refrigeration is safest.

6. Stir halfway through (optional but recommended).

What “good” looks like: A gentle stir to re-submerge any grounds that have floated to the top.
Common mistake: Skipping this. It helps ensure all the coffee grounds have a chance to extract evenly.

7. Strain the grounds.

What “good” looks like: You have a clean cold brew concentrate, free of most sediment. Use a fine-mesh sieve lined with cheesecloth or a dedicated cold brew filter.
Common mistake: Rushing this step. Incomplete straining means gritty coffee. Be patient and let gravity do its work.

8. Second strain (if needed).

What “good” looks like: The liquid is crystal clear. If you still see fine particles, strain it again through a finer filter (like a coffee filter).
Common mistake: Settling for a cloudy brew. A second strain makes for a smoother sip.

9. Dilute to taste.

What “good” looks like: You’ve added water, milk, or ice to reach your desired strength and flavor. Start with a 1:1 ratio of cold brew concentrate to water/milk and adjust.
Common mistake: Drinking the concentrate straight. It’s usually too strong. Always dilute unless you like it super intense.

10. Store properly.

What “good” looks like: Your cold brew concentrate is in an airtight container in the fridge. It should stay good for up to two weeks.
Common mistake: Leaving it uncovered. This allows it to absorb fridge odors and lose its freshness. Seal it tight.

Common mistakes (and what happens if you ignore them)

Mistake	What it causes	Fix
Using pre-ground coffee	Weak, muddy, or bitter brew; hard to strain	Grind whole beans fresh, just before brewing.
Grinding too fine	Bitter taste, sediment in the final brew, hard to strain	Use a coarse grind, like sea salt.
Using tap water	Off-flavors, metallic or chlorine notes	Use filtered or spring water.
Incorrect coffee-to-water ratio	Too weak or too strong brew; wastes coffee	Start with 1:4 by weight for concentrate, adjust to preference.
Not stirring during steep	Uneven extraction, weak spots in the brew	Stir halfway through the steeping process.
Insufficient straining	Gritty, sludgy coffee; unpleasant mouthfeel	Strain twice if necessary, using fine-mesh sieves and cheesecloth.
Steeping for too short	Weak, watery, underdeveloped flavor	Steep for at least 12 hours, up to 24 hours.
Steeping for too long	Bitter, overly strong flavor; can extract tannins	Stick to the 12-24 hour window. Taste test after 12.
Not cleaning equipment	Rancid oils, stale flavors, potential mold	Wash all equipment thoroughly after each use.
Storing uncovered	Absorbs fridge odors, loses freshness	Store in an airtight container in the refrigerator.

Decision rules (simple if/then)

If your cold brew tastes bitter, then you likely used too fine a grind or steeped it for too long because those factors extract unwanted compounds.
If your cold brew is weak, then you probably didn’t use enough coffee or didn’t steep it long enough because the ratio and time are key to strength.
If you see a lot of sediment in your final brew, then your grind was too fine or you didn’t strain thoroughly enough because those are the main culprits for sludge.
If your cold brew has a “sour” taste, then it might be underdeveloped, meaning you need to steep it longer or use slightly warmer (but still cold) water because under-extraction causes sourness.
If you want a stronger concentrate, then increase the amount of coffee grounds or decrease the amount of water in your initial steep because a higher coffee-to-water ratio makes it stronger.
If you want a less intense brew to drink straight, then decrease the coffee-to-water ratio or plan to dilute more because a lower ratio means less concentrated coffee.
If your cold brew tastes stale, then it’s likely been sitting too long or wasn’t stored properly because cold brew has a shelf life, typically about two weeks.
If you want to speed up the brewing process slightly, then consider using slightly cooler-than-refrigerated water (but still cold, not warm) because a tiny bit of warmth can slightly increase extraction speed.
If you’re using a French press and get grounds in your cup, then ensure your grind is coarse enough and press the plunger slowly and steadily because those are the main factors for clean French press coffee.
If you’re using a mason jar and cheesecloth and still have fines, then try adding another layer of cheesecloth or a paper coffee filter for the final strain because a finer filter catches smaller particles.

FAQ

How much coffee grounds do I use for 1 gallon of cold brew?

For a 1-gallon batch (128 oz of water), a common starting point is about 16 oz of whole coffee beans by weight. This usually yields a concentrate you’ll dilute.

What kind of coffee beans are best for cold brew?

Medium to dark roasts are popular for cold brew because their flavors are more pronounced and less acidic. However, any fresh, quality beans you enjoy will work.

How long should I steep my cold brew?

Generally, 12 to 24 hours is the sweet spot. Longer steeping leads to a stronger, more intense flavor. Start with 18 hours and adjust from there.

Can I use pre-ground coffee?

You can, but it’s not ideal. Pre-ground coffee is usually too fine for cold brew and can lead to a muddy, over-extracted, and bitter result. Coarse, fresh grounds are best.

What is the best water temperature for cold brew?

Cold brew means cold water. Room temperature or refrigerated water is perfect. You don’t need to heat anything.

How do I store my cold brew concentrate?

Store it in an airtight container in the refrigerator. It should stay fresh for up to two weeks.

Do I drink cold brew concentrate straight?

No, it’s typically made as a concentrate. You’ll want to dilute it with water, milk, or ice to your desired strength. A 1:1 ratio with water is a good starting point.

Why is my cold brew bitter?

Bitterness usually comes from grinding the beans too fine, steeping for too long, or using water that’s too hot. Ensure a coarse grind and a 12-24 hour steep at cold temperatures.

What this page does NOT cover (and where to go next)

Specific coffee bean varietals and their flavor profiles for cold brew.
Detailed comparisons of different cold brew maker brands.
Advanced techniques like nitro cold brew infusion.
Recipes for flavored cold brews or additions.
The science behind caffeine extraction in cold brewing.