Brewing Instructions

Shake your way to cold brew coffee

Rumble Jars come with quick instructions on the hangtag, but the detailed instructions below can also be 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. Happy to help!

Step 1: Load and lock the filter

Pour coffee (coarse grounds are preferable) into the stainless steel filter and secure the silicone cap.

Fill Rumble Jar with coffee grounds gif

How much coffee you use is up to you. We suggest filling it to the Normal notch (about one third full), and seeing how that tastes. If you want a stronger brew or even concentrate strength, try adding more grounds during your next batch and fill it as high as the 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 capped filter into the empty Mason jar. Pour cold water into the jar (you can pour it directly on top of the cap). Just ensure that you completely fill the jar, so the water level should be all the way to the neck. Since coffee grounds like to float, this ensures they stay underwater for the steeping process.

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

Now for the fun part...shaking your way to cold brew coffee!

If you're using coarse grounds, give it 2 quick vertical shakes (i.e. tipping the jar vertically end-over-end).

If you're using fine grounds, give it 2-4 more shakes. Fine grounds can sometimes form a barrier to steeping (since grounds tend to float and stick to each other), so these extra few shakes help 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 that, it's 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!). Voila! Clean-up est terminé.

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

Step 5: Get Brewsy

Drink it straight from the Mason jar! Have some coffee left over? 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. However, if you brew with fine grounds and really dislike the silt that's characteristic of cold brew, it might be something you'd like to use. If so, refer to our separate FAQ about the filter bag for more info on using it with the Rumble Jar.