Big starter question

So I made this big-ass starter, 3.5 liters, to hopefully come up with a little over 320 billion yeast cells for my 1.068 OG beer I'll be brewing on monday. I pitched the starter on wednesday morning and its still bubbling away, I expected it to be done by now. It has however, appeared to clear a bit. Is this length of time normal? My usual 1 liter starters take like 2-3 days.

....why did you make such a huge stater for a 1.068 beer? Is it a lager? What is the batch size?

I would recommend shaking it or getting it on a stir plate if you can, and taking off the airlock. You want as much oxygen as possible to get into your starter.

ugh did I get the size wrong? (5 gal batch, ale not lager) doh. I figured I needed 320 billion based on this page:

http://ezinearticles.com/?How-Much-Yeast-Do-I-Need-For-Brewing-Beer?&id=5360019

I poured a wyeast activator into 3.5 liters of starter wort made with DME... how much yeast will I have then when its done? If I have too much, I should just set some aside right?

ugh

I see your logic here. Most people 'round these parts use this: http://www.mrmalty.com/calc/calc.html

which is kind of a fun little calculator that you can use. Jamil (I think) recommends .75 million cells/mL/degree plato as opposed to your 1 million, but the difference shouldn't matter too much.

I think the main discrepancy here is that the article you referenced assumes a simple starter--one that you don't shake or otherwise mess with until pitching. This is not going to be as effective as shaking or not nearly as effective as a stir plate.

So, putting your information into Mr.Malty, you have to make a 1.67 L starter if you shake intermittently. Do yourself a favor and put some sanitized Al foil on top of the starter so you can get some more O2 into your starter, which the yeast need to grow.

You are not going to overpitch (by a considerable amount), I can almost guarantee it. Just give your flask/jug/whatever a few shakes whenever you think about it. Also, with such a huge starter make sure to fridge it overnight before pitching so you can dump out most of that beer, because ~1 gallon is going to make a significant contribution.

Thanks for the info. However, I made a 3.5 liter (almost 1 gal) starter! Isn't that way too much compared to the 1.67l one you mentioned? Keep in mind I'm not shaking though. And I am doing the aluminum foil cap thing already.

With no shaking, I got 2.89 L on Mr.Malty. I would still say that's okay, just don't worry about it (possibly have a home brew). As far as I'm concerned, it's better to slightly overpitch than to underpitch (in most cases).

I always make my starters slightly larger than recommended, just in case I don't have the presumed amount of viable cells.