How to Make Cold Brew Coffee at Home with a Mason Jar

Cold brew coffee is a summertime favorite, but you don't need a fancy machine to enjoy it. With just a mason jar, some coarse coffee grounds, and a bit of patience, you can brew a smooth, low-acid concentrate that's perfect for iced coffee, lattes, or even a splash in your morning smoothie.

In this guide, we'll walk you through the simple steps to make cold brew at home using a mason jar. We'll also share tips for choosing the right coffee, adjusting the strength, and storing your brew so it stays fresh. Whether you're a cold brew newbie or a seasoned pro, this method is easy, affordable, and yields delicious results every time.

What You'll Need

To make cold brew in a mason jar, you'll need a few basic items: a large mason jar (at least 32 ounces), coarse coffee grounds, cold water, a fine-mesh strainer or cheesecloth, and a container for storing the finished concentrate. If you don't have a strainer, a clean, thin kitchen towel works well too.

The type of coffee you use matters. Since cold brew is steeped for a long time, the flavor of the beans really shines through. A medium or dark roast with chocolatey or nutty notes works beautifully. For a convenient option, try Chamberlain Coffee's Organic Variety Cold Brew Singles—they're pre-portioned and designed for easy cold brewing. If you prefer to use your own beans, ask your roaster to grind them on the coarsest setting, like you would for a French press.

• Use a 1:8 ratio of coffee to water for a concentrate, or 1:5 for a stronger brew.
• Coarse grounds are key—fine grounds will make your cold brew cloudy and bitter.

Step-by-Step Instructions

Start by adding your coffee grounds to the mason jar. For a standard 32-ounce jar, use about 1 cup of coarse grounds. Pour in 4 cups of cold, filtered water, making sure all the grounds are saturated. Give it a gentle stir to combine.

Cover the jar with a lid or a piece of cheesecloth secured with a rubber band. Let it steep at room temperature for 12 to 18 hours. The longer it steeps, the stronger and more concentrated the brew will be. After steeping, strain the mixture through a fine-mesh strainer lined with cheesecloth to remove the grounds. You can strain it twice if you want a cleaner cup. Transfer the cold brew concentrate to a clean jar or bottle and refrigerate.

• Steep for 12 hours for a milder brew, up to 18 for a bolder flavor.
• Don't steep for more than 24 hours—it can become overly bitter.

How to Serve and Store Your Cold Brew

The beauty of cold brew concentrate is its versatility. Mix it with equal parts water or milk for a standard cold brew, or add more liquid for a lighter drink. You can also use it to make iced lattes, mochas, or even coffee cocktails. For a sweet twist, try Chamberlain Coffee's Organic Caramel Coffee Blend—just brew it as directed and add a splash of vanilla syrup.

Cold brew concentrate stays fresh in the refrigerator for up to two weeks. To keep it at its best, store it in a sealed glass jar or bottle. If you like your coffee extra cold, pour it over ice in a Double Wall Mug to keep it chilled without condensation. And when you're on the go, a mason jar with a lid works perfectly.

• Dilute concentrate with water or milk to taste—start with a 1:1 ratio.
• Use filtered water for the best flavor; tap water can add off-notes.

Tips for the Best Cold Brew

To elevate your cold brew game, consider a few pro tips. First, always use fresh coffee beans. Stale beans will result in a flat, dull brew. Second, don't skip the coarse grind—it's essential for a smooth cup. If your cold brew tastes bitter, you likely over-steeped or the grind was too fine.

Experiment with different coffee origins and roast levels to find your favorite. A light roast will bring out fruity and floral notes, while a dark roast offers bold, chocolatey flavors. For a ready-to-use option, Chamberlain Coffee's Organic Variety Cold Brew Singles are perfect for travel or when you're short on time. Just steep and enjoy.

• Try adding a pinch of salt to the grounds before steeping to reduce bitterness.
• For a fun twist, steep with vanilla beans or cinnamon sticks.

Making cold brew at home with a mason jar is simple, cost-effective, and yields a smooth, delicious concentrate that you can enjoy all week. With just a few ingredients and a little patience, you'll have your own home cold brew ready to mix into your favorite drinks. So grab a jar, some quality coffee, and start brewing—your iced coffee will never be the same.