DIY Coffee Concentrate: Simple Steps For Homemade Cold Brew

Quick answer

• Use a coarse grind and cold water for a smooth, low-acid concentrate.
• Aim for a coffee-to-water ratio between 1:2 and 1:4 by weight for a strong base.
• Steep for 12-24 hours at room temperature or in the refrigerator.
• Strain thoroughly using a fine-mesh sieve, cheesecloth, or specialized cold brew filter.
• Dilute your concentrate with water or milk to taste, typically a 1:1 or 1:2 ratio.
• Store in an airtight container in the refrigerator for up to two weeks.

Who this is for

• Home coffee drinkers who want a rich, smooth, and less acidic coffee experience.
• Those who enjoy iced coffee or want a versatile coffee base for various drinks.
• Individuals looking for a cost-effective alternative to pre-made cold brew.

What to check first

Brewer type and filter type

The vessel you use for brewing and the method of filtration are crucial for cold brew concentrate. For steeping, a simple jar or pitcher works well. Filtration is where most variation occurs. Common options include:

• French Press: The built-in plunger can act as a first stage of filtration, but a secondary filter is often needed for a cleaner concentrate.
• Cold Brew Makers: These often have a permanent filter basket designed for coarse grounds.
• DIY Setup: Using a large jar with cheesecloth, a nut milk bag, or a paper filter lined in a sieve are all viable.

For a DIY setup, consider using specialized cold brew filter bags like these to make straining your concentrate a breeze.

150 Pcs Cold Brew Bags 4x6 inch, No Mess Disposable Cold Brew Coffee Filter Pouches with Drawstring Large Empty Tea Bag for Loose Leaf Tea, Iced Coffee, Herbs, Spice, Home brewing, Hot pot

• Cold brew bags bulk: You will receive 150 pieces disposable cold brew coffee filter bags with drawstring. Enough quantity can meet your daily needs and share them with your family or friend
• Filter bags size: Each cold brew coffee pouches measures 4x6 inches/ 10x15 cm, can hold a cup of coffee grind and suitable for 32 oz jars. After brewing, put it in the refrigerator and enjoy the delicious cold brew coffee after 12-24 hours
• Material: These disposable coffee filter bags are made of degradable non-woven fabric, safe and odorless. The drawstring is designed to be easy to use, and the top drawstring prevents internal particles from escaping
• Fine mesh design: These cold brew pouches have sturdy double thread stitching and fine mesh design that allows the water to fully soak the coffee powders, whether coarse, medium and fine. No flavor is affected and no particles remain
• Multi-purpose: These large tea bags can be used for hot and cold brew coffee, and are also suitable for loose leaf tea, herbs, soup stocks, spices, hot pots, seasonings, foot baths, etc

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Water quality and temperature

The water you use will significantly impact the final taste.

• Quality: Filtered water is recommended. Tap water can contain minerals or chlorine that impart off-flavors. If your tap water tastes good to drink, it’s likely fine for coffee.
• Temperature: For cold brew, the name says it all – use cold or room temperature water. This is key to the extraction process, which is slower and gentler than hot brewing, resulting in lower acidity and a smoother flavor. Avoid hot water entirely for this method.

Grind size and coffee freshness

The grind size is paramount for cold brew concentrate.

• Grind Size: A coarse grind, similar to breadcrumbs or sea salt, is essential. Too fine a grind will over-extract, leading to bitterness, and will also make straining difficult, potentially clogging your filters.
• Freshness: While cold brew is forgiving, using freshly roasted beans will yield the best flavor. Aim to grind your beans just before brewing for optimal aroma and taste. Pre-ground coffee can work, but it may be stale and contribute to a less vibrant concentrate.

Coffee-to-water ratio

This is where you control the strength of your concentrate.

• Ratio: A common starting point is a 1:2 ratio of coffee to water by weight. For example, 100 grams of coffee to 200 grams (or ml) of water. You can adjust this based on your preference, ranging from 1:4 for a milder concentrate to 1:1 for a very robust base.
• Measurement: Using a kitchen scale for both coffee and water ensures consistency. If you don’t have a scale, a common volumetric ratio is about 1 cup of coffee grounds to 4 cups of water.

Cleanliness/descale status

A clean brewing setup prevents off-flavors from lingering old coffee oils.

• Brewer: Ensure your brewing vessel, any filters, and storage containers are thoroughly cleaned before you begin. Residual oils can go rancid and impart a stale taste to your fresh brew.
• Descaling: While not as critical for cold brew as for drip machines, if you use a coffee maker for hot water that you then cool, ensure it’s free of mineral buildup. For cold brewing, focus on the cleanliness of your steeping and straining equipment.

Step-by-step (brew workflow)

1. Grind Your Coffee: Measure your whole beans and grind them coarsely.

• What “good” looks like: The grounds should resemble coarse sea salt or breadcrumbs.
• Common mistake: Grinding too finely. This can lead to a bitter, muddy concentrate and difficult straining.
• How to avoid: Use a burr grinder set to its coarsest setting, or pulse a blade grinder carefully.

2. Measure Coffee and Water: Weigh your coarse coffee grounds and your cold or room-temperature filtered water according to your desired ratio (e.g., 1:2).

• What “good” looks like: Accurate measurements ensure consistent strength and flavor.
• Common mistake: Using volume measurements inconsistently.
• How to avoid: Use a kitchen scale for both coffee and water for the most reliable results.

3. Combine Coffee and Water: Place the coffee grounds in your brewing vessel (jar, pitcher, cold brew maker) and pour the water over them.

• What “good” looks like: All grounds are saturated with water.
• Common mistake: Not ensuring all grounds are wet. This leads to uneven extraction.
• How to avoid: Gently stir to ensure complete saturation, then give it a gentle stir to ensure all grounds are wet.

4. Steep: Cover the vessel and let it steep.

• What “good” looks like: The mixture sits undisturbed, allowing for slow extraction.
• Common mistake: Agitating the coffee too much during steeping.
• How to avoid: Let it sit peacefully. A gentle stir once or twice during the long steep is acceptable, but avoid vigorous shaking.

5. Choose Steeping Location and Time: Steep at room temperature or in the refrigerator for 12-24 hours.

• What “good” looks like: A long, slow extraction process.
• Common mistake: Steeping for too short a time. This results in weak, underdeveloped flavor.
• How to avoid: Stick to the 12-24 hour window. Longer steeps can sometimes lead to bitterness.

6. Prepare for Straining: Set up your straining apparatus. This might involve lining a fine-mesh sieve with cheesecloth, using a nut milk bag, or having your cold brew maker’s filter ready.

• What “good” looks like: A clean setup ready to separate grounds from liquid.
• Common mistake: Using a filter that’s too fine initially, leading to clogging.
• How to avoid: Start with a coarser filter if you have multiple options, or use a paper filter as a final polish if needed.

7. Strain the Concentrate: Slowly pour the steeped coffee mixture through your prepared strainer into a clean container.

• What “good” looks like: Liquid coffee flows through, leaving the grounds behind.
• Common mistake: Forcing the liquid through too quickly. This can push fine particles through and create a cloudy result.
• How to avoid: Let gravity do the work. You can gently press the grounds to extract more liquid, but avoid squeezing too hard.

8. Second Strain (Optional but Recommended): For an extra-clear concentrate, strain a second time through a finer filter, like a paper coffee filter or a clean piece of cheesecloth.

• What “good” looks like: A clear, sediment-free concentrate.
• Common mistake: Skipping this step if you prefer a very clean cup.
• How to avoid: If you notice sediment after the first strain, run it through a finer filter.

9. Store Your Concentrate: Pour the finished concentrate into an airtight container and refrigerate.

• What “good” looks like: A well-sealed container protecting the coffee from odors.
• Common mistake: Leaving the container unsealed. This allows the concentrate to absorb fridge smells and lose freshness.
• How to avoid: Ensure the lid is tightly secured.

10. Dilute and Serve: When ready to drink, dilute your concentrate with cold water, milk, or your preferred liquid.

• What “good” looks like: A balanced, delicious beverage.
• Common mistake: Not diluting enough, resulting in an overly strong and bitter drink.
• How to avoid: Start with a 1:1 ratio of concentrate to diluting liquid and adjust to your taste.

Common mistakes (and what happens if you ignore them)

Decision rules (simple if/then)

• If your cold brew tastes bitter, then you likely used too fine a grind or steeped for too long because these factors lead to over-extraction.
• If your cold brew is weak and sour, then you probably didn’t steep it long enough or didn’t use enough coffee because insufficient extraction time or ratio results in underdeveloped flavors.
• If your filtered coffee has sediment, then your filter might be too coarse or you agitated it too much during straining because finer particles can pass through larger openings or be forced through.
• If you want a stronger concentrate, then use a lower water-to-coffee ratio (e.g., 1:1.5 instead of 1:2) because this means more coffee is extracted into less liquid.
• If you prefer a less intense coffee flavor, then use a higher water-to-coffee ratio (e.g., 1:4 instead of 1:2) because this dilutes the extracted coffee more.
• If you notice off-flavors, then check your water quality and the cleanliness of your equipment because impurities or old oils can significantly impact taste.
• If you’re in a hurry, then a 12-hour steep is the minimum, but be aware it might be less robust than a longer steep because extraction is a time-dependent process.
• If you prefer a smoother, less acidic coffee, then cold brewing is the right method because the cold water extracts fewer of the bitter acids compared to hot water.
• If you want to make a larger batch, then simply scale up your coffee and water measurements proportionally because the ratio is the key to consistent results.
• If your concentrate tastes “muddy,” then you likely used too fine a grind or your filter isn’t fine enough because fine particles are suspended in the liquid.
• If you’re new to cold brew, then start with a 1:2 coffee-to-water ratio and a 18-hour steep because this is a widely accepted baseline for good flavor.

FAQ

How long does homemade coffee concentrate last?

Your cold brew concentrate should be stored in an airtight container in the refrigerator and will typically last for up to two weeks. Taste it periodically to ensure freshness.

Can I use pre-ground coffee for cold brew concentrate?

Yes, you can, but it’s not ideal. Pre-ground coffee can be stale, and it’s often ground too finely for cold brew. If you must use it, try to find a coarse grind and be prepared for a potentially less flavorful result.

What’s the best way to strain cold brew concentrate?

A multi-stage approach is best. Start with a coarse sieve or French press to remove the bulk of the grounds, then strain again through a fine-mesh sieve lined with cheesecloth, a nut milk bag, or a paper coffee filter for a cleaner concentrate.

How do I dilute my cold brew concentrate?

The most common way is a 1:1 ratio of concentrate to water or milk. However, this is a matter of personal preference. Start with a 1:1 ratio and adjust by adding more liquid until it reaches your desired strength and flavor.

Can I use hot water to speed up the cold brew process?

No, using hot water defeats the purpose of cold brewing. Cold brewing relies on a slow, low-temperature extraction to produce a smooth, low-acid profile. Using hot water will result in a different, hotter coffee extraction that is not cold brew.

What kind of coffee beans are best for cold brew concentrate?

Medium to dark roasts are often favored for cold brew as they tend to have chocolatey, nutty, or caramel notes that come through well. However, lighter roasts can also yield interesting results, often with more fruity or floral characteristics. Experiment to find your favorite.

Why is my cold brew concentrate bitter?

Bitterness usually stems from over-extraction. This can be caused by grinding your beans too finely, steeping for too long, or using water that is too hot. Ensure you’re using a coarse grind and sticking to the recommended steeping time and cold water.

Can I make hot coffee from cold brew concentrate?

Yes, you can! Dilute your concentrate with hot water instead of cold, using your preferred ratio. This is a quick way to get a cup of hot coffee that has the smooth profile of cold brew.

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

• Specific recommendations for coffee bean origins or roast profiles.
• Detailed comparisons of commercial cold brew makers.
• Advanced techniques like Japanese-style iced coffee (flash chilling).
• Recipes for specific cold brew cocktails or coffee-based desserts.