Yeast Starters and Stir Plates

[brechbräu]

So, I’ve been using yeast starters for quite some time and have recently added in the addition of a stir plate. My understanding was that the added aeration from the stirring would increase the yield of yeast in the starter. I’m not sure I’m noticing much of a difference, though. I use the Propper canned malt extract starter, yeast nutrient, and the yeast… am I missing something?

Thanks for any tips or advice you can give!

 

[day_trippr]

I have used many yeast propagation/pitch rate calculators, and they all agree: between doing nothing, occasional shaking, and using a stir plate, the yield markedly increases in that order.

fwiw, I favor Brew United's Homebrew Dad calculator, but the other two are virtually interchangeable with that one...

https://www.brewunited.com/yeast_calculator.php
https://www.captainbrew.com/yeast-pitch-rate-and-starter-calculator
https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/

Cheers!

 

[Tony B]

I agree with day tripper about the calculator.
Stir plates are pretty cheap ($20ish) on Amazon. I liked the first one I bought but it didn’t last a year. I’m not liking the second one I bought as the speed dial is not consistent. When this one dies I’ll probably look into a better quality model.

 

[day_trippr]

fwiw, I built my own stir plates, and if I could I'd provide a parts list, but these were put together back in 2013, and it was pretty much a "back of the napkin" design...

 

[RM-MN]

A stir plate will get you the increased amount of yeast the fastest but shaking witl get you to approximately the same increase.

 

[Gozie Boy]

fwiw, I built my own stir plates, and if I could I'd provide a parts list, but these were put together back in 2013, and it was pretty much a "back of the napkin" design...

View attachment 873714

I like the look of those permeable stoppers on your 5L flasks. Where do you find these, or did you also make them yourself?

 

[day_trippr]

I bought those from Morebeer probably 15 years ago. They had two sizes back then, a 2" diameter for 2 liter e-flasks, and a 2.5" diameter for 5 liter e-flasks. Today, Google can find the 2" size at all the usual places, but it isn't finding the larger size anywhere.

Cheers!