Stir Plate Starters.

[Lindsay Dive]

I have recently made a stir plate and have made two beers using the two litre starters which have been on the stir plate. I am using a two litre Erlenmeyer flasks on the stir plate.
I have noticed that there is a huge increase in the amount of yeast in these starters and one particular ale that I made last week took off like a rocket when I pitched the yeast and was completely fermented within four days at 18 degrees. The yeast I was using is the Whitelabs WLP025 Southwold Ale Yeast. What I have noticed however, is that the yeasts ability to flocculate has been severely affected by the stir plate starter process.
Has anyone else noticed this problem or am I simply off on the wrong tangent?
I will be taking a real keen interest in the Bohemian Pilsner that is fermenting at the moment!

 

[sosman]

I have recently made a stir plate and have made two beers using the two litre starters which have been on the stir plate. I am using a two litre Erlenmeyer flasks on the stir plate.
I have noticed that there is a huge increase in the amount of yeast in these starters and one particular ale that I made last week took off like a rocket when I pitched the yeast and was completely fermented within four days at 18 degrees. The yeast I was using is the Whitelabs WLP025 Southwold Ale Yeast. What I have noticed however, is that the yeasts ability to flocculate has been severely affected by the stir plate starter process.
Has anyone else noticed this problem or am I simply off on the wrong tangent?
I will be taking a real keen interest in the Bohemian Pilsner that is fermenting at the moment!

[post="89781"][/post]​

Lindsay my observation is that in the starter at least, the stirred yeast seems to flocculate more quickly. I have heard this anecdotally from others also but this is by no means a closed issue.

 

[Shunty]

I'd have to agree with sosman. I did an alt with a stirred starter of 1007, and a kolsch with a non stired starter. The alt was clear in a week of secondary, the kolsch took 3 weeks. Not exactly a scientific trial though, different grain bills, probably different temperatures etc.

 

[Stagger]

My last brew was a Dortmunder, I made my stater up over the week before brew day, however it had a funky smell so I ditched it (first one ever). I had all ready started brewing so no turning back, the only yeast I had was a very very small container taken from the smack pack. After getting to pitching temp I pitched the yeast and crossed my fingers. After 2 days no activity at all (I had the temp set at 15C), so I put my magnetic stirrer under my s/s fermenter and put the magnet in and switched it on over night (more like 12 hours). The next morning it was of and running, it may well have already started before I started stirring it but considering it very small amount of yeast I pitched I think it would have been lawn food if I didnt use the stirrer. They are great and it not the first time I have used it in this way.


Stagger

 

[Lindsay Dive]

[[/quote]
Lindsay my observation is that in the starter at least, the stirred yeast seems to flocculate more quickly. I have heard this anecdotally from others also but this is by no means a closed issue.

[post="89784"][/post]​

[/quote]
I must agree that the yeast seems to form colonies 'on the move' in the stir plate starter and settle a lot faster when the stir plate is switched off. But I have also noticed that the 'beer' is a lot cloudier than if a stir plate was not used.
I am just about to step up an Oktoberfest yeast today.
I might add that my stir plate does NOT create a vortex and simply stirs the wort.
There is a fair bit of study to take place on this issue as far as I'm concerned. I might even start splitting starters. I normally create 50 litre batches and then split it into two 30 litre fermenters, so a split brew with a split starter could very well be on the cards!! Then I'll know for sure what's going on.

 

[Gout]

mine seem to drop bright far quicker with a stired yeast.. even less scientific than others results

so quick and easy are my starters with the stirer i havn't used any other method since so i cant compare

 

[Lindsay Dive]

mine seem to drop bright far quicker with a stired yeast.. even less scientific than others results

so quick and easy are my starters with the stirer i havn't used any other method since so i cant compare

[post="89798"][/post]​

Does your stir plate create a vortex right to the bottom of the vessel?

 

[Gout]

yes, however i only use that to airate the wort at the start, then i slow it down as much as i can (this keeps the CO2 from building up). If i turn it off, when i turn it back on the CO2 rushes out and it foams all over the place.

with a 2Lt i wont have a vortex to the base of the flask. The vortex size is also dependent to the bar i place in there(size) and that inturn effects the RPM i can get out of my fan.

sounds complex but i normaly just use what ever is in reach and then get back to drinking beer

 

[Lindsay Dive]

I somehow thought that most folks were using their stir plates to form a constant vortex.
Okay, I think I've sorted that out know. I can only achieve a vortex when I have straight water in the flask and as soon as I put wort in there the viscosity seems to bugger up the whole situation and it just stirs.
I sure know what you're talking about when you switch the stir plate off for a while and then turn in back on......whoooshka!!