Yeast Starter

Instead of using packaged yeast, can I create a starter from my own beer?

Thanks.

Yes you can. Search here for yeast washing and yeast starter. Pretty simple thing. You bascially harvest your yeast cake...

sorry if im hijacking because this probably isnt what he meant, but i wonder....
can you make a yeast starter from a bottle of beer? i practice harvesting my yeast cakes but is there enough in a single bottle to get a good culture?

I have taken a crack at this. Homemade stirplate from harddrive magnet and computer fan, etc. Erlenmeyer flask and teflon-coated stirbar.

I washed the yeast from the last batch with cooled, pre-boiled water. Separated the yeast layer from trub, etc.

Pitched it into a 'starter wort' and let the stirplate rip.

After 1 day it smelled yeasty, more like bread than brewing beer.

After 2 days, it has a noticable acohol aroma. I suspect the yeast have passed the 'exponential growth phase'.

From what I understand I have a couple days to chuck it into a batch for optimal fermentation. I will make a batch in the next couple days here.

Thanks for all the replies. I have to admit vmpolesov, you lost me with the whole harddrive magnet stirplate doeymagingie. I'll check the link for yeast starter and yeast washing, which I'm starting to guess is required as part of the beer making yeast starter process.