First time using stir plate

[cm02WS6]

Hopefully this is an easy question. I used my stir plate for the first time last night. I'm excited to finally be able to pitch the correct population. Made a 1.2L starter in a 2L flask, put it on the stir plate and got a dimple going about half way deep. Then this morning I check on it and there's a layer ~3/8" of krausen on top and no dimple. It won't pull a vortex even at top speed. Is this OK? It is definitely stirring around in there but I'm just wondering if it is normal.

Thanks!

 

[bad67z]

Sounds normal as the starter thickens with healthy new yeast the vortex will reduce at the same given speed.

 

[TomRep]

Agreed. Also, sometimes there is a vortex but the krausen doesn't allow you to see it. When that happens for me, I just set it up to have a nice, moderate speed stir just to keep the yeast in suspension.
tom

 

[BBL_Brewer]

As you reach high krausen, it will thicken up and spin slower. Perfectly normal. As the starter reaches completion it will start spinning faster again and the dimple will reappear.

 

[WhiskeySam]

You should see some circular motion. If you're not, it's possible your stir bar has become "dislodged" from the magnetic force and is just bouncing around in there. Turn your stir plate off completley. Slide it around just a little bit on the stir plate surface to allow the stir bar to re-center itself and then turn it on again. You don't need top speed with these things, just enough to keep everything swirling.

 

[Brew-boy]

You do not always need a vortex, just keep the yeast in suspension and moving around. There will be plenty of O2 getting exchanged. You did fine and welcome to the stir plate club...lol

 

[friday]

Don't worry about it, as long as there is a slight circular motion on that half dollar size krausen you see in the middle your good.

 

[oakbarn]

If it that thick, the stir plate did its job. I let it rest and settle and pour off the clear starter wort and pitch the yeast cake. I add cooled wort and swirl around and the pitch.

 

[Brewham]

Just keep it moving - you don't need a tornado in there. After the krausen subsides (24-36 hours) if you put it in the fridge overnight (or longer), that will help the yeast fall out. Pour off the "beer" on top and add liquid to get the yeast up in suspension again before you pitch.

 

[cm02WS6]

Awesome! Thanks for the confirmation. I figure I'll turn if off tonight so it will settle in time for pitching tomorrow afternoon. This will also be my first time using oxygen injection and temp control so I'm excited to see the improvements. Going to be a Chinook and citra pale ale, 1.055 OG.

 

[WhiskeySam]

If you're going from no temp control, no O2, and no starter to temp control, O2 and a starter you're going to think you just started a new sport. The differences in your fermentation time and the quality of your beer will be fairly obvious. You've taken your first step into a larger world.

 

[cm02WS6]

That is what I'm hoping. I have done starters, but just simple 1L starters for the 9 or so batches I've done. Constant evolution I suppose....