I wont make a new thread as this has been done before and is similar to making a starter from a Wyeast smackpack (Whitelabs vial) as explained here -
Link
So here is my method - re-culturing yeast from a bottle.
1. Chill the bottles of CPA or CSA for a few days to make sure the yeast settles to the bottom of the bottles. Check the best after dates, the fresher the better.
2. Gently pour the beer into a glass leaving the yeast behind. Drink the beer
3. Give the bottle a swirl and pour the yeast remaining into a sanitised jar/flask.
4. Make a starter - I would start small and go for a 250mL starter (25g LDME, 250mL boiled, cooled water). Add this to the yeast and either add an airlock or cover with gladwrap/rubber band. Shake the starter until your arm is about to drop off. Every time you walk past the starter give it a good shake.
5. You need to 'step' this starter up and in practice its best to do this at high krausen rather than letting the fermentation finish. Its not really an issue if you let it ferment out as sometimes the first step wont show much of a krausen. Don't be concerned if it takes 24-48 hours to show any signs of fermentation.
6. Make a 2L starter (200g LDME, 2L of boiled, cooled water) and pitch the entire 250mL starter into this.
I would let this ferment out completely, crash chill and then pour off the beer and pitch only the slurry, particularly if you ferment the starter in the mid 20s as the coopers yeast will produce banana esters my the truckload at that temperature.
Try to ferment your CSA clone at 16-18C. Any higher and you will get banana esters. I actually don't mind banana in this beer as long as its not overpowering. At 16-18C it produces pear/apple esters.
This a a pic of step 4 - the 250mL starter. You can do this in a PET soft drink bottle. Cover in gladwrap and secure with a rubber band.
And this is the step up to 2L. Again, you can do this in a plastic container, you will need at least 3L for this step. This was my 3L flask until i broke it.
Clear as mud?
Cheers
DrSmurto
Anna
But I still don't really understand whether it's the POR, the yeast or the malt which gives it that distinctive taste (the similar to VB taste). It's the first taste that hits your mouth and nose - can't really taste it after the first couple of mouthfuls. 
Anna
Anna
