Yeast starter for Lager?

First, harvested yeast will keep for a year. You would have to purchase DME for starters for yeast that old, though.

There are lots of ways to harvest yeast. I use a gallon wine jug. After bottling my beer, I add little more than a gallon of water to the fermenter and swirl up all the gunk at the bottom. Then I let it sit 10 minutes. This allows all the heavy material to fall to the bottom and the lighter, healthy yeast to stay in the liquid. Then I fill up my gallon wine jug with the liquid and put it in the fridge. After about 3 days, when the yeast is nicely settled at the bottom of the jug, I decant most of the liquid and split the yeast into smaller jars. I split up ale yeast into 3 jars and lager yeast into 2. If I’m using the yeast within a month, I just pitch the jar into the batch. Over that and I make a starter. Yeast is a pretty big part of the beer budget but harvesting yeast will save you hundreds. Out of 1 pack of yeast, you can make 121 ales or 31 lagers. I have not gone beyond 5 generations but when I move to all-grain brewing I’ll see how far I can go before the yeast stops doing it’s thing in small 1-2 gallon batches.

After the yeast have done their “thing” in the initial starter, you basically have beer with yeast on the bottom. At this point there is no more sugar for the yeast to consume. So you cool this down so the solids and remaining yeast settle to the bottom and pour off the beer. You are stepping up the amount of yeast at this point by adding more starter wort (fresh with lots of sugar) for the yeast to get excited about again. They will ferment this new batch pretty quickly cause they are wide awake.

At this point you have beer on the top again, the wort has been consumed. So you chill down, let it clear and just before you pitch it to your new 5 gallon batch, you pour off the beer again and leaving just a little liquid, swirl it around good to loosen up all the yeast and pitch into your 5 gallons of wort. If done right with a double stepped lager yeast, you are probably pitching somewhere around 1/2 to 3/4" of a cup of slurry into your newly brewed batch.

Does this make more sense?

[Edit] sorry, I did not see page two where everything I said had been said before

So for a plain old Octoberfest I can use 1 smackpack and a rather larger starter? Correct?

Yep. Just make the appropriate size starter.

If I want to brew an Octoberfest this coming Saturday, today is Sunday, would there be enough time to get a starter ready?

Single stage, definitely. For two stages that might be pushing it, but if the yeast is fresh you could probably get it done.

I don’t know what a singe or two stage is

Two stage simply means creating the starter twice. First one is normal and you let it do its thing, then you chill, pour off the liquid and add more fresh wort. Using Mr Malty (.com) you can calculate how much healthy yeast that buys you. I am brewing two lagers tonight and I stepped up each starter twice. Probably a good thing because both were really slow to start.