New stir plate - results are in

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

old_tx_kbb

Supporting Member
HBT Supporter
Joined
Dec 25, 2009
Messages
217
Reaction score
8
Location
Nashville, TN
Imperial IPA's are one of my favorites to brew. I'd just gotten a new stir plate to see if it would help me get FG's to below 1.018 with a WLP001.

I made a starter and stepped it up once and pitched 1.7L into my latest all grain Imperial IPA. The OG was 1.094.

I'm going to keg it this weekend. FG is 1.012.

I thought my therminator was my best investment....nope...

I'm convinced my new stir plate is my best investment!

Cheers!
 
What size stir bar did you use? I built a plate but just can't get the stir bar to stay on the magnet (keeps getting thrown off). The stir bar is 2" and I've used a few different configurations of hard drive magnets with no luck
 
What size stir bar did you use? I built a plate but just can't get the stir bar to stay on the magnet (keeps getting thrown off). The stir bar is 2" and I've used a few different configurations of hard drive magnets with no luck

I've read a lot of people having problems with the two and going down to one inch bars.
 
I had seen some and have a 1" on the way. Size matters it seems - thanks!
 
it's a 1" x 5/16" or maybe 50mm

I used a 2000 ml erlenmyer flask. I made a 800 ml starter then bumped it up to a 1.7L starter. The vortex was small and didn't go down to the bottom of the flask. I got the right RPM dialed in so that it wouldn't throw the bar.

I just bought a 2 inch/100mm bar with a center ring to try out next.

My stir plate helps me make huge starters with less volume. I am totally sold on stir plates. I was pretty happy with my Imperial IPA's finishing at 1.018...but 1.012 is awesome!
 
My stir plate helps me make huge starters with less volume. I am totally sold on stir plates. I was pretty happy with my Imperial IPA's finishing at 1.018...but 1.012 is awesome!

So when using a stir plate I can make starters with higher gravity? What ratio do people typically use? I built one recently and besides stirring, I haven't changed anything about my starters.
 
You don't want or need higher gravity starters. You're looking for yeast reproduction, and that's dependent on how much oxygen and yeast are in solution, which is what a stir plate gives you. Higher gravity just stresses them out when what you're looking for is a higher number of healthy yeast.
 
What size stir bar did you use? I built a plate but just can't get the stir bar to stay on the magnet (keeps getting thrown off). The stir bar is 2" and I've used a few different configurations of hard drive magnets with no luck

If you have a harbor freight in the area they sell rare earth magnets in a pack of 10 I think for like $2 or $4 I can't remember. Either way they're a steal there compared to other places. I used three on each side with a spacer to not screw up the fan motor. I have a 2" stir bar and have no problems with it being thrown even with it at full tilt. Of course I did put a resistor in line because I used a 12v power supply and that was a tad too much juice and it would throw the bar even at the lowest setting on the potentiometer.
 
I won't repeat every word that smokinghole said above, but I could. HD magnets (3, stacked) only worked well with a 1/2" bar. And that DID work very well, and if I wasn't and endless doodler I would have kept that one. But I had a 2" bar that I really wanted to work, and I already had a large stack of small round rare earth magnets.

Rare earth magnets, 2 stacks, each stack contains 3. The stacks must have opposite polarity (one stack is north on top, the other south on top). Stacks separated by 1.5". Works perfectly with 2" bar.

PA150001.JPG


PA150002.JPG


To get it just right, I taped the fan assembly together, magnets and all, then taped to workbench. I then set my stir plate platform just above it with flask. This way I could keep changed the magnet position until I got it right. Then I hotglued the fan to the plate.

PC220005.JPG
 
"You don't want or need higher gravity starters. You're looking for yeast reproduction, and that's dependent on how much oxygen and yeast are in solution, which is what a stir plate gives you. Higher gravity just stresses them out when what you're looking for is a higher number of healthy yeast."

+1

Use a stir plate to increase the volume of yeast cells. A high gravity starter is not beneficial for your yeast.

On this recent brew, I oxygenated my starters for about 10 seconds and added yeast nutrient. I also added yeast nutirent during the last 10 minutes of my boil. I oxygenated my cooled wort for 60 seconds just prior to pitching my 1.7L starter. My Imperials always have a violent early primary fermentation, so I always use a blow off tube
 

Latest posts

Back
Top