Yeast on stir plate- How long?

I have a 1300ml starter in a 2000ml flask fro a dunkelweizen Im brewing today. My question is since this is the first time I have used a stir plate vs just making a starter is how long can I keep it aerating on the sitr plate? It has been there for about 15 hours now. I dont want to over- do it if too much aeration is a bad thing for a starter.

No. The whole point of a stir plate is constant aeration so that the yeast reproduce in larger quantities. Remember, when making a starter, you are not making beer you are making yeast.

I keep it on the stir plate until its done.... usually 24 hours. I then let it sit out for another 6 hours or so (in order to let the yeasts renew their glycogen stores), and then cool it for another 24 hours in the fridge so I may decant and then pitch (once the yeast come up to 60* or so).

That's all it takes? I left my stirplate on for like 1.5 weeks.

With a lot of yeast strains, you can tell when it's done on the stir plate because you'll see the wort go from this uniformly cloudy thing to a swirling mass of particles.

24 hrs. and you're usually good to go. Don't out think it. RDWHAHB

24 hours is usually plenty. The liquid gets a milky look and if you stop the stir you will see the yeast falling to the bottom. I usually pitch the whole thing but others like to decant off the liquid.

I find that in the summer, 18 - 24 hours is plenty. In the winter, I usually leave it for about 48 - 72 hours. In the fall, I sometimes get caught out, and don't leave it long enough.

-a.

How much do you guys think this varies by strain?

I've got 1 vial of the WLP570 Belgian Golden Ale Yeast in about 1300mL in a 2000mL and I couldn't keep the stir plate on b/c it keeps frothing over!

cjever19 said:

How much do you guys think this varies by strain?

I've got 1 vial of the WLP570 Belgian Golden Ale Yeast in about 1300mL in a 2000mL and I couldn't keep the stir plate on b/c it keeps frothing over!

Click to expand...

Yeast persnickitiness totally is related to strain. I'm constantly blowing Belgian and german wheat strains out the top of my 2000mL Erlenmeyer on the stir plate.

Then again, I'm constantly trying to fill the whole thing up with a 2000mL starter. I'm realizing that it can't be done with those super-active strains. English strains may be more manageable. (Though, the Wyeast 9097 Old Ale blend spewed all over as well when I attempted a 2000mL starter a couple weeks ago. I lost so much yeast I was compelled to purchase another packet.)

The sad moral of this story is that, though I had strategized to be able to make 2000mL starters on a stir plate in my 2000mL flask, it's not a practical possibility. I think I'll have to stick with 1000mL starters, maybe pushing it to 1500mL for some of the calmer English strains. If I'm brewing a beer that really needs as much yeast as a 2000mL stir-plated starter would produce, best just to brew a smaller batch first and harvest.