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Maelstrom® Stir Plate


SKU# 40332

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The first industrial-grade programmable stir plate designed specifically for yeast starters.

Breed a Herculean army of yeast for brewing bigger beers than ever before. Powerful rare earth magnets churn through any size starter and never throw a stir bar. Five-speed control adapts to sizes from minute to mammoth, for starters in a 1000ml erlenmeyer flask, all the way up to a 5-gallon carboy.

Command a massive starter while you’re at work or over the weekend. Let it run indefinitely or program up to 48 hours of stir time. Schedule it to settle out yeast just in time to come home and brew.

Watch Maelstrom® surge through starter wort. The transparent body shows the magnets whipping through rotation. Plus, the seamless surface makes for easy cleaning.

Easy to use with an intuitive interface, the Maelstrom® sets the new standard as the most powerful and versatile homebrewing stir plate ever created.

*Erlenmeyer Flask not included


Availability: In stock

Maelstrom® Stir Plate

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  • Maelstrom® Stir Plate
  • Maelstrom® Stir Plate
  • Maelstrom® Stir Plate
Product Details


  • Now includes a 50mm stir bar!
  • Five distinct speeds, from 480-1440 RPM, to accommodate yeast starters up to 5 gallons
  • Scheduling function for up to 48 hours
  • Seamless surface for easy cleaning & maintenance
  • Powerful magnets will never throw a stir bar
  • Translucent body lets you watch the magnets in rotation
  • Standard 12V Power Adapter
  • Large 8” W  x 8 ½” L stirring platform

*Erlenmeyer Flask not included

Be sure to check out the Fermenter's Favorites® Yeast Starter Kit in 1000 ml and 2000 ml sizes.

Additional Information
Support Documents:Maelstrom® Stir Plate
4.4 / 5.0
93 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
I would not recommend this product. Stay away from it!
The first one that arrived came out of the package with some scratches on it. I could live with that. The disappointment set in when I went to use it. The motor does not have the power to start the bar spinning. I had to assist the unit to get the bar spinning. Once it was spinning it worked fine. Unfortunately that is not so easy when dealing with a murky substance.
The company sent a second unit out, it was worse. The second unit looked as if it was used, probably somebody else's returned unit. The top was covered with scratches and scuff marks, the graphic overlay that covers the switches was peeled up and had bubbles in many areas and this second unit would also not start the bar spinning without asssistance. This is a waste of money. The ad itself is also a bit deceiving as far a be "programmable " , it only has a built in timer. Big Deal! Save your money and buy the less expensive $60 units with better (infinite variable) speed control. If you like to set it to stop after a certain time, get a lamp timer for a few bucks, you will be much happier?
January 3, 2017
Bad Design
The weight of a loaded flask pushes the flimsy plastic top into the magnetic rotor. Makes an awful noise as it grinds againt the top, if it spins at all (I had to lift the flask to get it to start spining) The description says it will stir a 5 gallon carboy. Yeah, good luck with that...
August 6, 2015
Works fine...sometimes.
So I took the plunge and splurged on this stir plate. Once I got it, I tested it out with water on a 2L flask with .5L water in it. Worked great. Then once I got my starter together later that week, the stirring arm would not turn enough to get the magnet going. I tried everything and then gave up.

Next batch, 2 weeks later, I got it going and it worked fine. Today I tried it and it did not spin. The stirring arm looked like it was trying, but could not complete the spin to get the magnet (in the flask) to properly spin. ?!?! I finally figured out that there might some polarity issue (?) and when I swirled the flask (with the magnet in it) in the right direction (once the magnet was centered), it worked like a champ. I don't think it should be doing this (it's not in the directions), but that's my workaround. Once it's spinning, it's great.
December 28, 2016
1 year ago
Tired of Messing Around with DIY Stirplates? This thing is AWESOME!
I've built several DIY stirplates over the years. I've had reasonable success with them - some were better than others. I thought I was satisifed. My most recent stir plate went tits-up, and I broke my 2000ml flask . For years I've been battling with my stir bars - sliding the flask back and forth to get a good lock, only to have it kicked off in the middle of the night when the starter got too thick, particularly with high-floc strains. Anyway - I've had success, but had a definitely love-hate relationship with my stir plates.I finally broke down and selected the Maelstrom - HOLY SHITE! Honestly, I had no idea what I was missing! This thing is incredible. I can get a nearly two-inch wide vortex in a 2L starter with ZERO signs of losing the bar. I don't subject my yeast to that kind of punishment, but if they get out of line...The pause button, the way it ramps-up the speed, the timer - they really have thought of everything - at least everything I need. Provided this thing holds up to a few hundred batches minimum, I think it was well worth the money. It is pricey, no doubt!Anyway, the entire time between ordering and receipt I felt like a douche. Really? On a stir plate? C'mon man. The moment I plugged it in and ramped it up, I was immediately glad I'd come off the cash for a purpose-built stir plate. Thanks NBNOTE - I purchased this in the yeast health kit w/ the Oxy2.0, new flask, etc so I will not show up as a verified buyer..
August 28, 2016
Response from Northern Brewer
Thanks for the great review! We are so glad you're enjoying the new tool! -Mike W, Northern Brewer
November 21, 2016
Northern Brewer
First stir plate, first starter.

I tested it when I got it and all worked fine. So I sanitized and prepared to make a starter for my next round of brew.

After getting everything together and placed in, I go to start the the stir plate and it basically mocks me by going forward a little and backward like it is stuck trying to move the bar.

I had to sit and fidget with things to try and line it up with no luck.

After many maneuvers to get the bar and magnet to catch each other the right way, it would take off. However, any slight bump or movement causes it to have its little seizure-spasm. For the price, I expect this to take the bar and grip it and rip it with ferocity to get it going. Not play tidily winks with it for the planets to align just right to line up.

Sad day.
January 24, 2017
8 months ago
doesn't work...
Received the stir plate, made my starter, turned it on... doesn't spin. Now I am trying to hand swirl my starter so my brew day isn't postponed. I feel like a $130 stir plate should be able to do more than sit silently on the counter. To be fair, I contacted NB support and they are replacing the stir plate, but it still sucks to have to deal with. I guess it's my fault for not testing it before making the starter and planning a brew day. Lesson learned. I will update my review when I get a functioning stir plate.
July 25, 2016
Powerfull & Relaible
First day of use: Solid funnel all the way down to the bottom. Nice aeration with No bar chatter. Spun a 2 liter starter like a blender. Even after the bar was buried in sediment. So nice to check it in the morning and find it still spinning.
December 19, 2014
it's good
I like it. It stirs.
August 18, 2016
5L no problem... first impressions
I rarely write reviews, but I wanted to let people who make large starters 5L and up that this stir plate actually does work. This isn't some project box and computer fan unit that you can buy from other sites. I purchased a so called 5L unit about a month before buying this one that lets say was less than adequate.So as I review this, I am coming at the unit from the stand point of 5L and larger starters.First the top of the unit looks to be one solid clear (all be it smoked clear) plastic. This shows off the motor and magnet unit which isn't some computer fan with PVC pipe and Magnets attached to it. Each polar magnet appears to be around 1x2 inches, its more than likely smaller then my estimate. However, the literature in the box claims it can hold a 3.5 inch stir bar (which I have not tried yet).My 5L flask sits on top with little overhang on the sides of the unit, what overhang there is is where the flask bottom begins to curve up to the top. Front and back there is even less overhang.The unit sits firmly on the counter and doesn't move when setting a 5L flask on it. It feels solidly in place and doesn't feel like its going to shift if bumped.Access to the controls are easy with a 5L. As you can see from the photo's there are 4 buttons, you have On/Off, Speed control (1-5), time (increments of 2 hours up to 48hrs) and last there is a pause button that defaults on, when you start up the unit. So you can set everything and without having any spin up or loss of time. (Likewise when you start everything up and and you're wondering why the unit isn't running its because the pause button is depressed).Currently with the 5L flask filled to the 5L mark at speed 4 and a 1inch stir bar I am getting a decent vortex. I currently do not have a 2inch or larger stir bar available at this time. As for the 1 inch bar, even at top speed, I have not been able to "throw" the stir bar. I should have a larger stir bar sometime next week and I will give it a try to see if I can throw the bar. I'll update this review sometime later.Items of note.There is some motor noise (discounting the stir bar noise) So if you are sitting in a room with it you will be able to hear it run. For me the noise was not enough to subtract a star for. But it could be for some.Price could be a factor for some. But if you want a solid unit for large starters and you do not feel like building one. This unit is a solid investment.Lastly it doesn't come with any stir bar. As strange as this sounds, for the price I kinda wish that it did come with a stir bar. I went back and forth on if I should deduct a star for this reason. Finally I decided I wouldn't deduct the star in the comments but rather leave you all with this.5 stars on performance and build.Adding price into the ratings this is a solid 4 star item. I hope that this helps anyone in deciding if to buy or not to buy.
January 9, 2015
Stir plate
Stir plate
September 30, 2015
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 18 questions Browse 18 questions and 48 answers
Do the glass big mouth bubblers work with this? I'm looking at this for yeast propagation at a brewery.
A shopper on Feb 9, 2017
BEST ANSWER: Yes it will work on the old style glass big mouth since the bottom is flat but will not work on the plastic big mouth due to the concave bottom. I'm not sure if the new style big mouths are flat or concave. For my home brew club, I was successfully able to propagate yeast for a 72 gallon pitch using this stir plate and a 6 gallon carboy. Make sure you buy at least a 2" stir bar. The short stir bar that comes with the stir plate is too short for a carboy.
Is the stir bar that is included resistant to boiling temperatures? ie can I boil the stir bar in the starter flask to sanitize/sterilize it?
A shopper on Mar 21, 2017
BEST ANSWER: This is what I do:
I measure 100 grams of Dry Malt Extract, 1/2t of yeast nutrient in a 2 liter Erlenmeyer flask, then fill it with RO water to the 1L mark. I drop in the stir bar, and stir for an hour. At the end of an hour, I put the flask on the stove. At the same time, I take my yeast out of the fridge (in a i Liter Erlen flask), and start the yeast warming up, on the stirrer. I always leave the stir bar in the fridge flask. When the one on the stove boils, I cover it with foil, and let it cool down. When the one on the stirrer and the one on the stove are both room temp, I mix them together, and spin overnight. When I am ready to pitch, I pour half in the fermenter, and half back into the small fridge flask. I do that forever. The big flask gets cleaned and sanitized, and the stir bar goes on the fridge door. After about 6 or 8 times, it starts to lose power, and slides down the door, but they work fine in the Maelstrom. The fridge door also has a tough time with all magnets, so I just make sure to have a big magnet below the stir bars.
Are there Replacement Magnets available? I've lost mine in a move and need to get brewing again!
A shopper on Dec 5, 2016
BEST ANSWER: If you mean the stir bar http://www.northernbrewer.com/standard-stir-bar
Is this unit based on a computer fan assembly?
P R on Dec 12, 2015
BEST ANSWER: Yes, and No, the unit is similar in design, however I've not seen a CPU fan with that torque, using magnets of that size at my local CPU supply store. The Malestrom spins a great 4l slurry in a 5L flask with just a one inch stir bar. That being said, speed and timer options along with a fairly stout polymer base make it a sound purchase. It's Fairly quiet and sleek. I myself prefer to craft beer not stir plates. Lastly if it fails to function, Northern Brewer will resolve my issues, keeping my business, instead of a couple of Box stores. Happy Yeast make GREAT BEER!
Is it correctly understood that this unit comes with a 120V AC/12V DC standard power adapter, which I can just change to a 230V AC/12V DC adapter myself, in order to use the unit in a country with 230V mains?
A H on Aug 2, 2016
BEST ANSWER: Yes, it has a US-style two prong plug on the transformer. The transformer accepts 120-240VAC (50-60Hz) and outputs 12VDC. A standard plug adapter (for example, two-prong US to UK) is all you should need.
Just opened it. Made my started, dropped in the magnet, turned on the plate... nothing happening. Am I missing something? I have set both the speed and time and it is not in the "pause" setting.
J L on Jul 24, 2016
BEST ANSWER: Customer service will contact you to try and troubleshoot or exchange for one that works without issue. It should be as simple as turn on, set time and speed, but you may need to hit the pause button to 'unpause' it if it was paused when started.
This isn't really a question but more of an experience I had with my plate.... The magnets were in pole to pole instead of opposites like it should have been... Had to flip one to make it work properly... the bar kept banging all around. Just wanted to share this didn't know where to do it... here looked good.
Gene R. on Mar 18, 2016
BEST ANSWER: That will happen with any stir plate to be honest. You have to move your flask or vessel around to find the sweet spot where the magnet makes the least noise
How long should you stir your starter yeast before you let it settle?
Mike H on Dec 10, 2015
BEST ANSWER: 12 hours
My routine is to start after work the day before brew day and I stir until I add everything the next afternoon which is between 9 to 12 hours.
I can see that this can do large volumes of liquid, but can also do small volumes such as 25 to 30ml, for doing total acidity testing in wine making with my Vinmetrica SC 300?
John C. on Nov 2, 2015
BEST ANSWER: I'm unfamiliar with the specific testing for the SC 300. That being said, I reviewed a few Youtube videos for the equipment and my guess for the limitations would be 1) length of the stir bar relative to the diameter of the test vessel, 2) if the vessel is light it might get spun with the stir bar, 3) the tip of the measuring instrument may hit the stir bar if the diameter of the vessel is too small and 4) the stirring speed on the Maelstrom is not infinitely adjustable (has specific speed settings) and the lowest setting may still be excessive for small volumes and would cause the liquid to splash out of the test vessel.

Hope that helps a little...good luck!
Finally got the unit and it won't power up. I took the cover off to see if there was something loose or anything like that, and it doesn't appear so. Circuit board doesn't have any noticeable defects, wires are making good contact. there's nothing that jumps out as faulty. Is there an FAQ page for this thing, or a manual more than the 1-sheet? I think i might have to return it, but would want to try to fix it if possible. Thanks in advance for the help.
J O on Aug 26, 2016
BEST ANSWER: Northern Brewer stands by their gear. My stir plate worked right out of the box. I would return it and get it exchanged. With the new white labs perfect pitch yeasts, my starters are just going nuts on the stir plate!! I'm pitching monster starters in less than 24 hours. It's a win win!!!
Can someone from Northern Brewer Verify is this will do 220V? I downloaded the tech speck from midwest supplies and it say 120V input, but that may be the device not the transformer. Also another buyer mention it had a capable transformer, but need to make sure before I buy this and take it half way across the world.
A R on May 24, 2016
BEST ANSWER: I run it on 110 vac in the US & it works fine. On 220v I would use an adapter or you may risk frying it on the first batch
I've had my Maelstrom for about a year and it ceased to function yesterday while spinning up a starter. Can't get it to start spinning again and the magnet bar appears to be tilted. Don't k ow how it happened as I wasn't around while it was running. What is the warranty period?
J O on Apr 24, 2016
BEST ANSWER: Hello John,

Thank you for choosing Northern Brewer! Was that stir plate purchased in store, or online? I am not finding a purchase for a Maelstrom under your account. We warranty our products for 1 year, but there is some flexibility depending on the situation at hand. If this was purchased in store, it will need to be taken up at the store. Here are the store direct lines Milwaukee 414-935-4097 Minneapolis 612-843-4442 St. Paul 651-289-4772. If it was purchased online, I can do a little more digging to see what I can come up with. Let me know, and we will get this figured out!
Who manufactures this ? and is it available in a 220V ?
A R on Apr 24, 2016
BEST ANSWER: My documentation does not indicate the exact manufacturer nor the place of origin. Maelstrom is the trade marked name, though. Includes a two-prong US-style power transformer (wall-wart) that accepts 100-240V, 50/60 Hz.
Cant seem to keep this quite. Magnet keeps banging around.
J I on Dec 18, 2015
BEST ANSWER: Should sound like a gentle hum. If it's on a hard surface, the sound will be amplified so try putting a towel or something underneath to dampen the noise. If it's making sounds beyond a hum, it may have been damaged. You should be able to look in there while it's spinning and may be able to notice any foul play.
That all being said, it's certainly not silent and you may be able to hear it humming along in a room even with the door closed. I'm assuming that mine is operating correctly and I've just moved it downstairs or in a more discrete location if the wife complains...Good luck.
Would this work for 230V (europe)
P K on Nov 19, 2015
BEST ANSWER: The Maelstrom is only compatible with standard U.S. 110 volt power sources.
I own a malestrom and it is great with 4 liter starters. I would like to do 6 gallon (22 liter) starter in plastic bucket or plastic fermenter with a flat bottom. Can you tell me the weight limit for the plate?
A shopper on Jun 24, 2017
BEST ANSWER: We do not know a weight limit for the plate, but we have on occasion filled a 6.5 gallon glass Big Mouth Bubbler with water and it has worked just fine. I would caution you about using plastic buckets or fermenters with the Malestrom, as any dimples in the plastic will inhibit the action of the stir plate.
Can this handle a 10-gal starter (yes, 10 gals of wort) in a keg as a fermenter?
A shopper on Apr 17, 2017
BEST ANSWER: Thanks for contacting Northern Brewer. I understand you want to make a 10 gallon starter, but the Maelstrom can handle up to a 5 gallon starter. If you were making starters larger than 5 gallons I could not guarantee this product would work for it. Cheers!
Does this come with a catch magnet to keep the stir bar from pouring out?
Mike H on Aug 30, 2015

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