This review is by Homebrew Finds Contributor Michael Gom.  Read more about Michael below.

Hands on Review: The StirStarter Yeast Stir Plate

Why make a yeast starter?

A yeast starter can really help insure you have healthy, viable yeast for your beer especially when using liquid yeast. For this reason I always prefer to build up a starter whenever using a liquid yeast (or re-pitching a saved yeast). I won’t get into effectiveness of different starter methods but a popular choice for homebrewers is to use a stir plate, a magnetic stir-bar and a flask of some sort (erlenmeyer flask in most cases).

Full disclosure, I was sent this product for free to do this review. Though I did try and put it through multiple real-world tests and have given my honest opinion on function and performance.

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Compare Prices, Review Continues Below:

• Stir Starter- Magnetic Yeast Starter Plate via Amazon
• Search Amazon for “Stirstarter”

Also Mentioned in this Review: Cole-Parmer elements AO-34502-65 Cole-Parmer Elements Erlenmeyer Flask| 3 Pack, Magnetic Stir Bar – 50mm / 1.96 Inch

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Unboxing and packaging

All the parts and components arrived in a single, compact zip-loc bag.In the bag, an information sheet with info on the company, yeast starters, etc.

Also included is an envelope with an instruction sheet, as well as the “keeper” magnet taped to the back.

As well as the power adapter (in it’s own cardboard box), the stir plate itself, and the stir bar.

StirStarter Features

A few features to note about this stir plate;

1. It comes with a stir bar and a keeper magnet (more on the keeper magnet later).
2. It has a detachable power supply, it can be unplugged from the back of the device. I find this to be a convenient feature as previous stir plates I’ve owned always had a tethered cord.
3.  Variable speed control, there is a control knob on the front of the stirplate that can increase or decrease the speed of the stir bar. Though difficult to see in the photo, there is a hash mark on the face of the control knob to show how high the setting is set (12’oclock position is off).
4. Rubberized feet to stop/reduce vibration and keep the stir plate from sliding around on a hard surface.

StirStarter Dimensions

The stir plate sits about 6 inches long, about 4 inches wide, and just over 2 and ¼ inches high.The stir bar is 1 inch long.

StirtStarter Test Runs

This particular model of the StirStarter is recommended for use with a 1 to 2 liter starter. They do have a larger model for up to a 5 liter starter. Knowing this, I wanted to test this stir plate’s ability to do a bigger starter in a 4 liter flask. To keep things fair, I used the stir plate in both a smaller 2 liter flask with a 1.5l starter as well as a 4 liter flask with a 3.5l starter.

Stir plate with a 2 liter flask.

4 liter flask. This 4 liter flask is almost comically large, and it hangs over the side of the stir plate by quite a bit.

2 Liter Trial

I did a water test with 1000ml, 1500ml, and 2000ml of water. This stir plate was able to produce a vortex easily in each test. I won’t bore you with pictures of each test, instead here is a picture of the 2000ml test (note the knob is at just over 50% here)Again, I know this stir plate is not meant for starters or flasks of this size. In this test I tested with 2000ml, 3000ml, and 4000ml of water, and once again the stir plate was easily able to produce a vortex all the way to the stir bar. Here is the 4000ml test (note the knob setting is about the same as the 2 liter test)Since I intended to test this stir plate with a larger flask/starter than it’s meant for, I also figured I would try it out with a larger stir-bar. This stir bar is 2 inches in length and quite a bit thicker than the included stir bar.I was anticipating this stir bar causing a much larger vortex and expected it to spin the liquid even faster. I hadn’t considered that this added size would increase the resistance against the liquid by quite a bit. The stir plate was able to spin the bar, but not at a fast enough rate to cause a significant vortex. Perhaps a slimmer 2 inch stir bar would have worked better in this test, but the included 1 inch bar works just fine. Pictured is the stir bar only getting the start of a vortex, the stir plate was set to the max speed. I will be sticking with the included 1 inch stir bar for my starters.

Yeast Starter Trials

To give this stir plate a full review, I wanted to include a few actual starters. I lined up two different brews, I won’t go into specifics on the recipes but the first one is an Ale with a 1.055 starting gravity and a batch size of 5.5 gallons in the fermenter. According to BrewUnited’s yeast calculator with my OG, batch size, age of yeast, and growth factor (.75 million/ml for ales) it calculated I needed a 1.5L starter which is what I made. Note that in these pictures, the volume is actually a bit higher than 1.5L because of the volume added from adding the liquid yeast. I used wyeast 1010 yeast.

The stir plate had no problem keeping the starter spinning. I left this starter for about 30 hours undisturbed. It didn’t throw the bar or stop working at all. Per my normal process, I cold-crashed the starter for 24 hours and on brew day I decanted most of the liquid off the top, keeping behind a healthy amount to swirl up with the yeast when I pitch it into the wort.This is where the included keeper magnet comes into play. I used it to fish the stir bar out of the bottom and hold onto it from the side. At this point you can choose to slide the stir bar up and grab it at the top, or simply leave it there while you pour your yeast into the wort. I found that it’s strong enough to hold onto the stir bar while I poured the yeast into my fermenter.

The second starter I made was for a large lager. Per the brewunited calculator, I needed a 3.2L starter, using wyeast bohemian lager 2124 yeast.Again this flask is much larger than this stir plate is designed for. As you can see it is much larger than the plate itself. Though it easily creates a vortex in the starter and keeps the liquid spinning. I left this starter for ~30 hours undisturbed and it didn’t throw the stir bar or shut off at all. Again the keeper magnet was able to hold up the stir bar after the starter was complete. I prefer to grab that stir bar before I cold crash just so I don’t forget and also so I don’t stir up the yeast later on.

Conclusions

This stir plate definitely performed as expected, it even exceeded expectations as it was able to handle a larger flask and starter without much issue. I really like the ability to disconnect the power cable from the back for easier storage, also the speed control is a nice feature too. It’s nice that it comes with a keeper magnet as well, it is no fun to forget about that stir bar and lose it in your fermenter.

I do think it is a bit small for a larger flask size as noted above, but it will definitely work. For someone like me that has never made a starter over 2 liters before, this would be an excellent purchase. It’s primarily meant for up to a 2 liter stir plate but can definitely accommodate a larger one from time to time as needed. The added utility from saving a little bit of money is nice, though a larger stir plate would probably be a better decision if you routinely or mostly make large over 2L starters.

Compare Prices

• Stir Starter- Magnetic Yeast Starter Plate via Amazon
• Search Amazon for “Stirstarter”

Also Mentioned in this Review: Cole-Parmer elements AO-34502-65 Cole-Parmer Elements Erlenmeyer Flask| 3 Pack, Magnetic Stir Bar – 50mm / 1.96 Inch

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More Photos

Included Stir Bar vs Larger Stir Bar.  As mentioned the included stir bar works better.Weighing DME for a starter using the Ozeri Pronto Digital ScaleFermenting using a Fermosnter Fermenter – Hands on Review

Thank to you Valuebrew for providing the unit used for evaluation in this review.

Thank you to Michael for this review!

More About the Author:  I’ve been brewing for about 8 years, started out with a 5 gallon extract kit and was hooked. Jumped into all grain after about 5 or 6 batches of extract. Since then I’ve run the gauntlet of partial mashing to building a cooler mash tun to BIAB. I recently switch to an electric all-in-one system and love it, this is my preferred method now due to ease of use and time saving. I have no professional brewing experience. I prefer pale ales and IPA’s mostly. Trying my best to be a good home brewer while also being a good family man for my wife and two kids!