Rumble Jar | The World's Simplest Cold Brew Coffee Filter

Rumble Jar cold brew coffee maker for a quart size mason jar

Cold brew made simple

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An Ultra Simple Cold Brew Coffee Maker for Your Home

Introducing the world's simplest cold brew coffee kit: Rumble Jar. We built a cold brew filter specified by coffee experts, and then designed it to work perfectly inside the classic Mason jar. Rumble Jar is all you need to make professional-quality cold brew coffee right at home, as cheaply and quickly as possible. Just add coffee and water and give it a rumble. Shake your way to cold brew coffee.

How it works

See how Rumble Jar works, in 92 seconds

How easy is it?

A simple 4-step process will get the brewing process started in under 1 minute. Then just let it sit overnight, and you'll have cold brew ready in the morning that tastes just as good as the stuff the pros make.

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Simple and smart.

To build the world's simplest cold brew filter, we needed to think through the smallest details. Rumble Jar looks simple, but it's packed full of smart features.

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Rumble Jar's cold brew coffee filter is beautiful and durable

Kickstarter reviews

We launched Rumble Jar on Kickstarter in November 2017, and we were blown away by the reception! If you missed the campaign but wanted to see how the early-adopters responded to their Rumble Jars, please read their reviews. (hint: we're quite proud of 'em!) The button below takes you directly to the Comment section, in all its 100% honest glory.

Reviews

Cold brew tastes better

There's a reason why you're always hearing about cold brew coffee, and that's because a lot of folks find it just plain old tastes better. The secret is that cold water extracts about 70% less acid from the coffee grounds than hot water, which means that your coffee ends up tasting a lot less bitter. So if you're new to cold brew, get ready to enjoy a smoother, sweeter flavor of coffee.

Cold brew science