[lominatrix]

I have seen a lot of videos and instruction blurbs about how to harvest used yeast and store for future use in another beer.  Is there a reason one can't buy a packet of yeast, pitch it into a starter set up to allow the yeast to multiply, then store again in smaller portions each ready to pitch into a 5 gallon batch, or to make a starter?  I haven't seen anyone describe how they are growing with new yeast before pitching once.  Would this yield a better yeast than using a yeast that has already lived through a cycle, since many say to pitch the re-harvested yeast in a lower gravity beer than the first?  If you know of a site describing the process, please post!

[alikocho]

It's doable. Someone explains it here - http://uk-homebrew.tripod.com/id45.html

Not sure I'd do this, as I'd rather make a slant.

[ndcube]

The reason for harvesting the yeast from a previous batch is because your brewing the batch anyway.  Creating a starter that large is more work than necessary IMHO.

many say to pitch the re-harvested yeast in a lower gravity beer than the first?

Usually you want the harvested yeast to be from a lower graivty, the theory being that it is less stressed.  Then you have lots of yeast to chew thru multiple low gravity batches or 1 or two high gravity batches.

[dbeechum]

Professional breweries often repitch yeast for many generations.

At least one brewery I know swore up and down that they didn't get good results with WLP001/Wyeast 1056 until they had repitched it into the 3rd generation and it really hit stride at approximately 7 repitches.

Now.. for you and me and Dupree in the brewhouse, we'd be pushing our luck much beyond 3 batches just because we aren't nearly as fastidious as our professional counterparts.