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We engineered the perfect filter to go inside a Mason jar. Beautiful equipment. Simple brewing. Delicious coffee.
We built the perfect cold brew coffee filter and desiged it to fit inside the time-tested Mason jar. It's beautiful, simple to use, and  makes delicious cold brew coffee with just one minute of prep time. NOW IN STOCK AND READY TO SHIP >>
We built the perfect cold brew coffee filter and desiged it to fit inside the time-tested Mason jar. It's beautiful, simple to use, and  makes delicious cold brew coffee with just one minute of prep time. NOW IN STOCK AND READY TO SHIP >>
1,259 backers pledged $53,635 to help bring this project to life.

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    1. Patricia Leung

      I have to say this is one of the best things I've ever backed on KS. I have a routine going where I make the coffee in the evening per instruction, stick it in the fridge overnight. I get another jar in the morning, stick the cloth sleeve in, then filter the coffee. I then throw about a tablespoon of condensed milk in the jar and whisk it will incorporated. Split the content with yet another jar, give one to the hubs and take one with me on the commute to work. In the evening I scrap the dried up grounds into my compost and plop everything into the dishwasher with the rest of the dishes. Since I got a 3 pack (gave one to my mom), I'm able to pipeline the process every day. It's been saving me a sbx trip (and $5) on a daily basis. Great stuff :)

    2. Missing avatar

      LEX on


      You’re welcome hope you like it!

    3. Rumble Jar Creator on

      @Kenny You're the best for posting this method! Will give it a shot this weekend. To anyone interested in trying a slightly different brewing method by a backer who has done a REALLY amazing job experimenting with his Rumble Jar, see Kenny's method below. The man knows coffee, so we trust it's a good one!

    4. Kenny Hubbahubbahubba Ng on

      Aaaand here's where I am at now. I got my hands on some really nice medium-to-dark roast from Brazil, and another from El Salvador.

      - 50g coarse grounds (14 clicks on my hario slim) consistently gets me up to between the first and second marking

      - plop the filter sleeve in, add in filtered water to the brim (I use a simple Brita filter. Filtered water makes a huuuge difference esp if you live in the city where the water is chlorinated. You'd be surprised at how much chlorine warps the aroma of coffee)

      - I rumble the jar once, then let it sit with the lid off for a minute. During this time, the grounds really soak in the water, and I'll commonly see the water level drop about a quarter to half inch. I top it up with more filtered water

      - let it sit 12 - 16 hours at room temperature

      - after removing the filter, I let the whole jar sit in the fridge for a few hours to let all the silt settle

      - tuck into the best coffee evar

    5. Rumble Jar Creator on

      @Roger Great idea. Rumble Jar's a great option for folks on a limited budget. Cold brew from stores tends to be seriously expensive.
      @LEX Awesome. One more thing we'll be trying out ourselves. Thanks for the pro-tip!

    6. Roger Smith

      I gave one of my RJs to one of my clients who is a shut in and on a limited budget. He no longer has coffee go to waste.

    7. Missing avatar

      LEX on

      Using the Rumble Jar for gen mai cha tea (Japanese pop corn tea). Works great!!! Gave one to my niece.

    8. Rumble Jar Creator on

      @Kenny Love that feedback! Great thoughts all around on a topic we spent a lot of time deliberating. Yep, we definitely encourage folks to experiment and figure out the amount of grounds that work best for them. We don't believe in hard-and-fast rules when it comes to coffee, and we built Rumble Jar with that philosophy in mind. While the two of us tend to fill grounds only to the first notch, we've heard from A LOT of others like you that they prefer it stronger and fill it to the second notch. There really is no reliable rule of thumb here either...we've seen recipes vary in their calls for water-to-grounds ratios by a full 3x on a post-diluted basis. So we just hope everyone is experimenting with it like you are!
      @Tim Many thanks for the follows!

    9. Kenny Hubbahubbahubba Ng on

      Btw to clarify, not a complaint. Just thinking if the good ole rumble jar is gonna be a gift to a newbie cold brew maker, their first attempt is gonna be to try the first non-concentrate mark. I'm wondering if a higher positioned mark might produce a more standard cold brew taste.

      Then again maybe my friends and I just drink too much coffee for our own good to begin with

    10. Kenny Hubbahubbahubba Ng on

      Just made made my 14th jar, and I have some questions:

      Has anyone tried weighing how much grounds it takes to reach the first mark vs the second mark (concentrate)?

      For my course grounds (between 12 to 15 clicks on my hario slim grinder), I get round about ~25g and ~50g

      I've been experimenting with medium roast and dark roasts (dislike light roasts), between 12 to 20 hours steep time, and consistently find that if I fill the filter up to the first mark (so about 25 - 28g) the coffee is a little too weak or diluted. These days I've settled mostly in between the first and second, so round about 40g.

      In most cases, by the time I remove the filter + grounds, the remaining volume of coffee is ~600ml. The vast majority of cold brew recipes online recommend a ratio of 1 part grounds to 5 - 6 part water.

      So.... Long story short: anyone else find the markings on the filter to be a little too low to make a standard drink? I've tested with 8 buddies and all seem to agree that the in between mark is more like a standard cold brew.

    11. Tim on

      @Rumble Jar gave you a follow on IG and Facebook. Can’t wait to see what products you offer in the future!

      @Maria if you want a refund because your international order hasn’t arrived yet that’s pretty sad. But to each their own. Rumble Jar is a great product you’ll be missing out.

    12. Rumble Jar Creator on

      @Maria Thanks for asking. We've previously had some dialogue with you through messages, so yes we definitely read and try to do a good job responding to all of them! It looks like your refund question was sent within the last 24 hours, and we just didn't have time to respond to it yet because we were attempting to get more info for you about your lost package. We'll respond to your message shortly with that info. Thanks for your patience!

    13. Missing avatar

      Maria Ermakovich on

      Guys do you see messages? I asked for refund via private message

    14. Rumble Jar Creator on

      All - Apologies for the delayed responses here! One of us was out all of last week, but now we're back and catching up.
      @James No worries! We're seeing it as delivered on our end, but we'll follow up directly with you and make sure to get to the bottom of its whereabouts. Just need to make sure we get you Rumbling ASAP!
      @Savinien Thanks so much for helping out other backers while we were away (and you're exactly right about the coffee sample not going to Europe).
      @Alex No worries at all, and we're glad you were able to find the answer in our campaign. We definitely take responsibility for the confusion, given we added international shipping mid-campaign, and so some of the details about our international rewards became a bit more difficult to message.
      @Maria A tracking notification email should have been sent to you via backerkit. We'll follow up directly with more details about your package. Thanks for your patience!
      @Lukas So happy to read that great feedback! Thank you!

    15. Missing avatar


      Yeah, I'm UK and while I have been given a tracking number it's got to Heathrow and hasn't moved since the 1st of May. Annoying is an understatement

    16. Missing avatar

      Savinien on

      @ Maria: got mine in France one month ago.

    17. Missing avatar

      Alex Bondo Andersen on

      @savinien I am from EU. Just read through the campaign text again, and you are right, coffee is only for US and Canada

    18. Missing avatar

      Maria Ermakovich on

      Any european backers to receive their jar already? Can you please provide me with tracking number for my shipment?

    19. Missing avatar

      Savinien on

      Are you an US Backer ? The coffe is US only i think.

    20. Missing avatar

      Alex Bondo Andersen on

      Just got my two rumble jars a couple of days ago and already been using it with great joy. I just noticed that I didn't get the "2× 4oz bag of Jittery John's coarse-ground coffee". Are these supposed to come in a separate shipment?

    21. Missing avatar

      Savinien on

      I just ordered more ball Mason jar to be able to brew multiple batch in advance for when friends are coming ( and those are not that easy to find in France..)

    22. Missing avatar

      Lukas Borys on

      Already used my rumble jar a few times. It’s awesome! Very beautiful! My girlfriend used it yesterday to make a cold brew! She’s is a non-coffee drinker...but she likes the Coffee that is coming out of the rumble jar.

      Thanks again!

      One little thing. The steel walls are thinner than I thought. Hope they don’t get broken or so...

    23. Rumble Jar Creator on

      @Zane @Geist @Tim Thanks to you all! Love hearing how happy you are with it. Yep, we definitely built these things to last for a long time. Guess our business model is to build something that really lasts and makes people happy they bought one so they go tell all their friends!!! ;)
      @Laurence Awesome! That kinda makes us feel bad for all your other coffee makers (just kinda...).
      @Nikole Great ideas. Re: bigger...we've been hearing that a few times. Something we'll definitely be looking into. Re: the plunger idea...are you thinking a french press style plunging mechanism? We'll follow up with you directly because we're curious to hear more about what you're thinking. Thanks!

    24. Zane

      @Geist - It was a joke...

    25. Geist de la Muerte Gatito

      @Zane: Making something that will break down after 6 months isn't sustainable for environment either.

    26. Tim on

      Followed you guys on Facebook and IG.

      @Zane, they could always make new cap colors or sell unique versions of mason jars with their logo stamped on it or other custom designs.

    27. Zane

      I honestly can't think of anything negative to say. A coworker saw me drinking fresh cold brew, asked about it, ordered, and a few days later he was sipping on a Mason jar and loving it too. Couldn't believe how quickly it came.

      Maybe a negative is that I'm not sure you found a sustainable business model making a product that lasts and needs no upgrades...

    28. Missing avatar

      Laurence on

      In love with my jar. Seriously use it every day since getting it. All coffee makers have been put away.

    29. Missing avatar

      Nikole Morris

      I love the rumble jar. Got it just in time for the random hot weather in NYC. Am I the only one that gets only 3 drinks out of my jar? Suggest for future rumbles, bigger. This is the perfect size so far me.
      I love the second filter, while I know it's gonna have silt I'm glad I can filter it out put it back in the jar. Thought: what about a plunger to push the water out of the ground. I have no clue if that will make the coffee taste funny, I just feel as if I'm not getting the water out.
      I also put sugar in my jar after I take the grounds out. Already sweetened coffee just waiting for milk.

    30. Rumble Jar Creator on

      @ktseng We've noticed pretty similar results between fridge and room temp (assuming you use the suggested steeping times of 8-12 hours at room temp and 16-24 hours in the fridge). But we would LOVE to hear what you or any other backers have discovered in your brewing experience so far.
      @Tim Love to hear it! We're kinda in awe at how good our gear looks after >6 months of daily brewing. Still looks like new. Glad you're finding the same!

    31. Missing avatar


      Is there a large difference in result from steeping in room temperature vs in a fridge for the suggested times?

    32. Tim on

      After a few weeks of using it, the green cap still looks brand new and filter rinses clean so easily. It is awesome. The wife says it makes the best cold brew she’s ever had.

    33. Rumble Jar Creator on

      @Lukas Great to hear! Yep, we've heard a few reports of international folks who were not alerted to their package waiting for their pickup. Everyone should get notified one way or another, but sometimes the local postal services neglect to do that. So if you're an international backer still waiting for your package, please use your USPS tracking number (which was sent to you via a backerkit email) to search in your home country's postal service package tracking database to see if your Rumble Jar is awaiting pickup. Or just reach out to us and we can look for you. Happy to help...we just want to make sure everyone gets their Rumble Jars. Thanks!

    34. Missing avatar

      Lukas Borys on

      Waiting at the customhouse to pay fees and get my rumble jar. My package was waiting there...

    35. Rumble Jar Creator on

      @Joseph it looks like yours has been awaiting pickup for a couple weeks! Guessing they never bothered to notify you. We'll follow up with more details in a separate message.

    36. Missing avatar

      Joseph Beck on

      Haven't received my rumble jar yet anyone in the UK have there's yet?

    37. Rumble Jar Creator on

      @Geist Sounds pretty cool to us! Thanks. We'll check it out.
      @Oscar Such amazing and helpful feedback. And that pro-tip about using different cap colors for different concoctions? Genius. Hopefully the thin walls will turn out to be OK for you. So far we've tried to beat up our filters a bunch and we've been impressed with how well they've held up (but we're not exactly the strongest folks out there!). Huge thanks again!
      @Savinien Such a pleasure hearing words like that. Thank you!

    38. Missing avatar


      So after a few days experimenting with my rumble jar(s), I have discovered its great for cold brew (OBVIOUSLY!!!) takes all of 2 minutes to fill the filter with coffee grounds, add water, shake, and leave it on my desk in the office to steep at room temp for my morning coffee the next day. At home, I also have made cold brew hibiscus tea with whole hibiscus flowers... again perfect.. less tart more floral no need for sugar. In my 3rd and final jar I tried fruit infused water with strawberry and can guess how that turned out. The possibilities are endless with the Rumble Jar.

      One thing I did notice is that the filter cap seems to absorb the smell of whatever has been steeping in the jar. Is there any chance you will be selling just the filter cap later on? It's great that they have different colors that way I can color code depending on what I steep in the jar on that day.
      Also if you ever make a version 2.0 of the filter down the line could you consider making it slightly thicker walled. I feel as if I could accidentally crush this one while washing it. Other than those 2 nitpicking concerns BEST KICKSTARTER PROJECT I EVER BACKED.

    39. Missing avatar

      Savinien on

      Got mine in France yesterday, and immediately put it to test. Very easy to use and wash, and good looking too.
      Tested my first cold brew this morning and i'm loving it!
      Since i'm a not an heavy coffee drinker ( i don't need it everyday and prefer quality over quantitie, the fact that i can keep a brew two week in my fridge is a big plus.
      Thanks much Rumble jar !

    40. Rumble Jar Creator on

      @Kenny Wow! Gonna have perma-blush all day with compliments like that. Huge thanks! It's the best hearing people loving their Rumble Jars.
      @Lukas Hope you love it! And hopefully it restores your girlfriend's faith in Kickstarter! It's a really amazing place/community with only a few occasional bad actors.
      @Paige @Oscar So glad to hear you're happy!!
      @Nathan That's very strange! It actually should have been delivered already. Thanks for bringing it to our attention. Our fulfillment guys are on top of it, and we'll follow up directly with you when we have more details.

    41. Tim on

      @kenny, yes the material is thinner than I thought too. But overall it’s amazing and brews amazing coffee!

    42. Kenny Hubbahubbahubba Ng on

      Side note: I've dropped Kickstarter an email to consider profiling this project as a case study of how a project should be run. I would encourage others to do the same!

    43. Kenny Hubbahubbahubba Ng on

      WELL WELL WELL. received both my rumble jars and gotta say I'm 100% happy with what I received. Machining is suh-weeeeeeet on the steel construction, albeit much thinner than I had expected it to be. The silicon caps are beautiful.

      Man. Overall, beautiful product, and the project management and execution was damn near flawless. Easily my favorite project to date. Congrats y'all I wish y'all the very best!

    44. Missing avatar

      Lukas Borys on


      Mine is shipping since 01.05. to Germany. It’s already in Frankfurt, but since 3 days or so stocked there. I check the status periodically...can’t wait to receive the package.

      My girlfriend is already saying that Kickstarter is fake 😂

    45. Missing avatar

      Paige Smith on

      Excellent product! I received all 3 of my Rumble Jars yesterday and the order was spot on; the jars, lid colors and snack bars were perfect. I only hope I can wait until Christmas to give my kids theirs. 😊

    46. Missing avatar

      Nathan Hendrix on

      Good afternoon! Thank you again for enabling shipping to South Korea. Tracking says it was shipped on April 25th and USPS is "Awaiting Item". Do you know how long international shipping has taken for other backers? Thank you!

    47. Missing avatar


      Had my 1st batch this morning with the included coffee. AMAZING!!! Usually a cream and sugar guy but today just plain black was perfect. Super easy to make too. I'm loving my rumble jar.

    48. Rumble Jar Creator on

      @ktseng Great questions! The instructions we included on the hangtag are pretty quick, so we've built out a detailed instructions tab as well as an FAQ tab on our website to provide folks with more info. Both sections are still a work in progress, but head to and check them out.
      @LEX @Kit @Roger Woohoo! Glad you all are loving it!

    49. Missing avatar


      Hi guys,

      Got my jar, looks great thanks! Perhaps I’m overlooking something, but where can we find more detailed instructions on how to make our coffee? Ie. should we be filling the filter to the top with grinds? How much water do we pour in? Above the plastic piece? Below?


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