Brewing Instructions

Here's how to shake your way to cold brew coffee

Rumble Jars all come with a set of quick instructions, but the detailed instructions below are a great reference when you begin brewing for the first time. We have an FAQ page that might be of help too, but if not then you can always send us an email. Now, let's get to Rumbling...

Step 1: Load and lock the filter

Pour coffee grounds into the stainless steel filter and secure the silicone cap. And remember: the experts agree that cold brew tastes best when brewed using coarse grounds!

Fill Rumble Jar with coffee grounds gif

How much coffee you use is up to you. We suggest filling it to the lower (Normal) notch, which is about one-third the way up the filter, and then seeing how that batch tastes. If you want a stronger brew or even "concentrate strength", try adding more grounds for your next batch and fill it up to the higher (Concentrate) Notch.

Personally, we tend to fill ours to the lower Normal Notch, and almost everyone who's tried a Rumble Jar prefers an amount somewhere between the two notches. But you should run an experiment to discover the perfect amount of grounds for you!

Step 2: Get your rumble on

Put the filter (with its silicone cap attached) into the empty Mason jar. Then pour cold water into the jar (FYI just pour it directly onto the silicone cap and the water will flow down through the channels into the body of the jar). Just ensure that you completely fill the jar so that the water level is all the way up to the neck. Since coffee grounds do like to float, this helps ensure they stay underwater throughout the steeping process.

Rumble Jar cold brew coffee in a Mason jar shake your way to cold brew coffee step

Now for the fun it a quick rumble!

If you're using the recommended coarse grounds, give it just two quick vertical shakes (i.e. tipping the jar vertically end-over-end). 

But if you're using the not-recommended (but still perfectly acceptable!) fine grounds, repeat this process one more time (i.e. two more quick rumbles). Fine grounds can sometimes form a barrier to steeping (since grounds tend to float, stick to each other and block the filter holes), so this extra set of rumbles helps ensure all the grounds get soaked during this step.

You know you're shaking correctly when you hear the rumble of the swooshing water (yep, that's where our weird name comes from!). The rumble process is technically known as agitation, and it is absolutely required to properly extract coffee from the beans. Don't believe us? Just try a batch without agitating it! Actually don't do'll be gross and a total waste of perfectly good coffee.

Step 3: Sleep-n-steep

After all that hard work, you've earned a much-needed rest. So go get some sleep, and in the morning you'll wake up to some delicious cold brew.

tired cat

Steeping guidelines we like to use:
If you're steeping in a refrigerator: 16-24 hours. 
If you're steeping at room temperature: 8-12 hours.

Step 4: Quick clean-up

Pull the filter out, dump the grounds, give the filter and cap a quick rinse or wash them with soap (Rumble Jars are totally dishwasher safe!). Voilà! Clean-up est terminé.

Rumble Jar cold brew coffee in a Mason jar easy clean-up

Step 5: Get Brewsy

You can drink it straight from the Mason jar! Have some coffee left over and want to store it? Just screw on the metal lid and stick the remainder in the fridge and drink it tomorrow. Cold brew lasts for up to two weeks.

(NEW!) Optional Step 4.5: Use the second-stage filter bag

That 100% cotton bag that comes with your Rumble Jar is designed to be a second-stage filter, so don't throw it away! But it's an added step that will be overkill for most folks, and unnecessary for anyone using the recommended coarse grounds. However, if you brew with fine grounds and you really dislike the silty particles that can be characteristic of cold brew made with fine grounds, then this second-stage filter might come in handy. If so, refer to our separate FAQ about the filter bag for more info on using it with the Rumble Jar.