Yeast from a previous brew

[StevieDS]

I'm planning an APA brew for a few weeks from now. Being a tight ****, I don't want to spend 6 quid plus delivery for a new vial of wlp001 yeast.
I have about 6 or 7 bottles of my first ag which was brewed with this yeast. Is it possible for me to harvest the yeast from these?
The thing is I, don't wanna drink all the bottles in one go, I'll only have 1 or 2 per night usually. Can I add the dregs to a sterilised jar, kept in the fridge, over the course of a week or so then just make a starter for this a couple of days before I brew? :hmm:

 

[pittsy]

yes but you would need to get the dregs as you said and add about 10g of dme and some boiled water just half a cup say and ferment for 1 to 2 days then up it to 50g for 2 days then another 100g 2 to 3 days before brew day and you'll have plenty of good fresh active yeast .

 

[StevieDS]

yes but you would need to get the dregs as you said and add about 10g of dme and some boiled water just half a cup say and ferment for 1 to 2 days then up it to 50g for 2 days then another 100g 2 to 3 days before brew day and you'll have plenty of good fresh active yeast .

So it's ok to wait till after I've collected all the yeast from all the bottles before I start to add the dme the way you suggest?

 

[pittsy]

just 1 bottle will do it , you may need a week or so but yes 1 is enough . :thumb:

 

[StevieDS]

Wow one bottle is enough? Cool, I may get cracking with it then if it takes a week to culture. Cheers for the advice :thumb:

 

[RobWalker]

from what i gather it's like mould on bread. you only need a tiny bit and you can grow a warehouse full if you need to. it reproduces!

and you're not a tight **** at all, WLP yeasts are very expensive, most people ferment it with 500g DME in a demi john and split it into 8 before they've even brewed with it for 8 starters - that's why it's good to pick one you'll use for many brews to come :

 

[rpt]

If you can harvest yeast from one bottle of commercial bottle conditioned beer you must be able to do it from a bottle of your own. Is it essential to build up the quantity over several days? How much do you need for a brew? There's a how-to here that uses 2L in a demijohn but is that for several brews? I've just bought some Worthingtons White Shield and Fullers Bengal Lancer and by the time I've harvested the yeast and grown it with DME it won't be a cheap way to get yeast at all.

 

[fbsf]

I've harvested RCH Pitchfork yeast using 100g of DME in 1L of water. It made one of my best brews to date.

Even at shop prices (£4 for 500g DME, so 80p worth) that's cheaper than buying decent yeast at £3 a packet. If you get the DME from someone like the malt miller, then it's £6ish for 1kg, which makes it a lot cheaper.

Obv if you add in the cost of the bottled beer, then it's about the same, but you do get to drink the beer!

 

[pittsy]

And remember liquid yeast is 9 times out of ten a better yeast thus better beer , also only some bottles will have the right yeast in them as many that do have yeast in them are pasturised then a different yeast is used for bottling .

 

[StevieDS]

Ok so let me just outline what I think the process is then...

Add 100g DME to 1 litre of water, bring to the boil and hold for 10 mins.
Pour into a sterilised mason jar, seal and allow to cool.
Pour my beer into a glass, leaving the sediment behind.
Swirl the bottle to rouse the yeast and pour into the cooled DME solution.
Leave to ferment for a couple of days then add to my wort.

How does that sound? Is it necessary to add the DME solution in increasing amounts as pittsy suggests?

 

[pittsy]

you will strain the yeast and end up with a yeast that may well be different from what you've started with , you want the yeast to be in the growth stage so want the gravity to be on the low side so doing it in stages helps the yeast to remain strong and active , yeast will change depending on what's going on .

 

[Good Ed]

You would be best to start by drinking 2 bottles of beer and using the dregs of 2 bottles in a small starter of say 300ml water with 30g of DME, let this ferment then step up with 1L of water with 100g of DME. As DME is best disolved with cold water do this and then boil for 15mins before cooling to 20C before pitching your yeast. Once your starter has finished leave it in the cool for say 24 hrs to let the yeast settle out then pour off the spent wort before stepping up. Before brewday do the same, and then on brewday pour off the spent wort, and add say 500ml of cooled wort from half way through your boil, this will then get the yeast raring to go before pitching.

 

[oz11]

Worth a read of this as a "how to".