Looking at creating my first yeast starter for a DIPA recipe with on O.G. target of 1.085.

For this O.G. Brewer's Friend is telling me I would need a 3L starter of an O.G. of 1.040 with a stir plate to hit my cell count (assuming yeast is 1 month old) (oh, I'll also be buying 2 packs of yeast).

The yeast starters work far better with a stir plate, however, stir plates cost an absolute fortune and there's no way I can justify spending that kind of money.

What viable alternatives are there to stir plates which will help the starter?

Maybe some sort of underwater fan? Placed in such a position to the side of the vessel it creates the same whirlpool?

Also, erlenmeyer flasks cost an absolute fortune. With additional headroom over 3L the flask would need to be 5L? At that size they are very costly. Altogether with a stir plate that seems to be coming in around the £500 mark. Is there any particular benefit of an erlenmeyer flask? Surely any ol' container will do? I've seen a pretty huge glass vase in the local charity shop for a few quid and I'm hoping to hear that'll do just fine.

  • 1
    Actually, on the container a 4.5L demijohn (glass carboy) should be just fine? Like this: wilko.com/en-uk/wilko-demijohn-container-glass-45l/p/0022556
    – joe92
    Sep 7, 2018 at 16:10
  • 3
    I was going to post a answer, but since it's not an alternative to stir plate, but how you could make one with less than $30. Well, there are dozens of step-by-step projects, but this one posted on braukaiser.com/wiki/index.php/PWM_Coltrolled_Stir_Plate_Design is very easy to follow and the parts are very easy/cheap to find on the internet. I've made one which is basically the same and works just fine. If you don't like electronics and stuff, find someone who likes and ask him/her to assemble it for you.
    – rondonctba
    Sep 7, 2018 at 18:00
  • @rondonctba The main reason for wanting an alternative is the price. Since your suggestion of building your own reduces the price to affordable levels it would be fine as an answer.
    – joe92
    Sep 10, 2018 at 9:10

4 Answers 4


You could build a stir plate - you probably already have most the stuff laying around.

Step 1: Gather a computer fan, power supply, stir magnet, and neodymium magnets and 2 L mason jars.

Step 2: Glue 2 neodymium magnets to the computer fan facing upward, with one + side up, the other - side up. The diameter should be the length of your stir magnet.

Step 3: Connect the power supply to the fan via the molex connectors and jumper the green wire to the black wire. The fan should spin, if you want to use a on off switch you should wire it in here, between the green and black wires from the motherboard connector. https://www.silverstonetek.com/downloads/QA/PSU/PSU-Paper%20Clip-EN.pdf

Step 4: Sterilize everything. Then, throw the magnet into the jar, set the jar on the fan to drive the stir magnet.

Step 5: Add water, yeast, and sugar at the amounts recommended by white labs.

  • 1
    I was just coming on to add an answer to say that I'd done this, thanks to the suggestion in a comment by @rondonctba. I made a few tweaks though which made it considerably easier to build. I used a USB fan with 3 settings, low/med/high, and plugged it in to a standard USB plug. Easy as pie. amazon.co.uk/ELUTENG-120mm-Computer-1500RPM-56CFM/dp/B071CL82G9
    – joe92
    Sep 17, 2018 at 9:07

I use a 750 ml bottle, sanitised aluminium foil and a rubber band. Keep aerated by stirring it gently, occasionally during the first 12h; I stir every 6th hour or so. After 18-48h I use it or refrigerate it for later use.

I use White Labs instructions for reference, no matter the brand of yeast I buy.



A stir plate does two things. Both can be done manually by swirling your vessel.

  1. Provides the yeast a good amount of oxygen.

  2. Reduces yeast lost, from lifting out with krausen and drying on the sides.

Put your starter in a common place like in the kitchen and swirl of whenever you walk by.

Erlenmeyer flasks are unique in that they are made of Pyrex and can be used to boil starter wort in on a gas burner. They also have a flat bottom for use on a stir plate. The tapered shape does little to aid a starter.

Any food grade glass vessel with an opening foil can cover is fine for a starter if you boil and cool wort before adding it to the vessel. 1 gallon wine jug work great and is much cheaper than a 5000ml flask. Mason jars are perfect for small starters.

Thrift stores usually have old coffee pots which work really well. They too are heat safe and have flat bottoms. If the pot has any plastic just remove it. Some may have a warning not to boil liquid in them, but in my experience this is because they have some plastic handle etc. I have used these over gas flames and in the microwave to boil wort water. enter image description here

  • Good points. Swirling also puts more yeast into suspension in the solution.
    – Martin
    Sep 14, 2018 at 6:03

I Use various size canning jars, I have the, from .5L up to Half Gallon. I only fill them up Half way to 3/4 full. And when making the starter, I leave the lid partially screwed on.

Then during the process, every time i walk by Open up the jar swirl Then I spend about 10 seconds shaking it with the lid on Tight. then crack it.

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