balazs

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I've been making yeast starters for a while now using the conventional 1 gallon jug with an airlock and have been able to grow lots of slurry without a problem. Lately I have been looking into making a stirplate. I just can't help but wonder though, is this something that will really make a better and healthier starter or is it more or less another brew toy (eye candy). I am aware that the stirplate keeps the yeast in suspension but how much healther does is make the yeast?

Homercidal

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I enjoyed making and using my stirplate. I honestly can't tell it it's making a real difference or not. If you aren't interested in it for the cool toys factor, then I'm guessing you can get good results by simply picking up the container and shaking or swirling for a few seconds each time you walk past it.

The stirplate basically just keep the yeast in suspension, allow it to contact more food than otherwise. Once you've shaken the wort up, you probably have as much O2 in solution as it can hold. There may be some further exchange of gas at the surface of the wort once the yeast start consuming the O2 already in the wort, but how much benefit a stirplate gives over occasional stirring is debatable.

Revvy

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A recent Basic Brewing Radio, may help you decide.

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BadgerBrewer

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I liked making my plate as well. Awesome when it was done and worked!

If you check out MrMalty (http://www.mrmalty.com/calc/calc.html) and the suggested pitch starter needed, you will note that when you select stir plate versus simple starter, that the size of the starter goes down considerably the higher gravity beer you are making. I would say that this means stir plates are more effective at making healthy and more dense yeast colonies.

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Homercidal

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The point is that a stirplate will definitely create more healthy yeast in less time than a simple starter. However, I think the term simple starter means just adding your vial to a stationary jar of wort.

I can't help but wonder but that the occasional stir is also going to be more effective than simply letting it sit there undisturbed.

So the simple answer is yes, a stirplate is much better than nothing, but stirring a few times a day is probably very helpful too, as an alternative.

I recommend building one. It's easy and fun. I made mine out of an old printer selector box and an old computer fan. I used hard drive magnets mounted on the fan, and an old mobile phone charger to power the fan. It's crude, but it works.

There must be many threads in internet land that show people's stirplates. Lots of cool ideas.

a10t2

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Essentially what I found is that *frequent* shaking is almost as good as a stirplate, and that direct aeration is the best technique of all: Aeration and Yeast Starters

Overall it seems that agitation doesn't do much in and of itself (for a low-gravity wort, anyway). The benefit of shaking or a stirplate comes primarily from turning over wort at the surface and increasing oxygen uptake.

I think that's a pretty good summary.

Barazs: you say you're using an airlock, which means that there will be almost no oxygen available once the yeast have exhausted the O2 in the headspace. At that point reproduction will stop and you'll only have fermentation going on. Other techniques for growing more yeast won't be effective unless you remove the airlock.

Sean

EricCSU

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Exactly. Use loosely wrapped foil on top

Eric

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balazs

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Good stuff! Thanks for all the info and links. Definatly will be making a stir plate after reading more on what they do for the yeast.

riromero

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I'm with you, brother. Computer fan and some kind of 9V charger I found in the bottom of my drawer is all I used too. But I can only make stirplate starters about 2/3rds of the time because I keep losing the damn stirbar. Seems like the stirplate method makes way more yeast.

EricCSU

Recipes 

Tape a magnet to the outside of the flask after using the stir plate but before pitching.

Eric

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Kegged: Belgian Dark Strong (8.9%abv)

Fermenting: Arrogant Bastard Clone, BCS Dry stout

Planned: Rye IPA, ESB, Oatmeal Pale Ale, Rye Amber

Can You Brew It Recipe Database
Convert an all grain recipe to extract
Hop Substitution Chart