Yeast Harvest

[Paddy]

I know there is tons of info on this and I have read up quite a bit about it.

Go a Saison being bottled next week. Seeing as the yeast is so darn expensive (WLP 565 = £7.00) is there any way to harvest AND preserve yeast for a prolonged period of time. Got an ESB and Porter lined up so next Saison won't be for a while.

From what I've read yeast can keep for up to a month at cold temperatures though it becomes dramatically less healthy after two weeks. Not sure if this is just what the big companies are feeding us to keep sales up...No offence to them as business is business.

Can't you just keep it sold and keep feeding it for a few months or something?

 

[pittsy]

Your easiest method here would be to save an inch of a bottle of saison then make a 100ml starter with 10g of dme then after 2 days make a 500ml starter with 50g and then after another 2 days make 2.5l with 250g and you have a nice large starter ready for a high gravity beer .

 

[evanvine]

You can keep your yeast in the fridge for months if you rinse it several times with demineralised water.
You can freeze it and keep it for years!

 

[rpt]

You can salvage the yeast from one of your bottles. Storing yeast under beer is a good long term solution.

 

[brewtim]

I've got a freezing experiment underway 30/30/30 yeast/beer/glycerine at home freezer temps. Also you could just start your fridge yeast every few (6 ?) weeks to keep it viable, although I suspect different yeasts will act differently e.g. Some yeasts may last years at 4 C and some will die within 6 months.

What we need is a mass experiment because there are myths and then there is reality.

 

[saccharomyces]

I kept a bank of slanted cultures alive in my brewing refrigerator for ten years. I could have kept my bank alive indefinitely, but I took a long hiatus from the hobby. Anyone who is seriously interested in learning how to slant and plate yeast should invest in a set of autoclavable screw cap culture tubes. A screw cap culture tube looks like a test tube with a screw-on cap. Screw cap culture tubes are designed specifically for culturing.

Here are a few photos that I shot recently when I made media and plated the dregs from a bottle of commercial bottle-conditioned beer:

Blank slants

Blank plates (poured hot)

Note: The proper way to make plates is to dry sterilize the petri dishes in the oven at 177C for 90 minutes and allow them to cool to 66C. The media is autoclaved (pressure cooked) at 121C for 15 minutes and allowed to cool to between 50C and 60C before removing the petri dishes from the oven and pouring the plates hot. Pouring plates hot minimizes the amount of condensation that forms on the inside of the lids.


A plate that has been streaked for "singles"

The colonies inside of the red rectangle are all the offspring of single yeast cells; therefore, they are pure cultures. When transferring yeast from a plate to a slant, one wants to select colonies that exhibit good morphology, which usually means selecting colonies that are round, domed, and creamy off-white. While it is difficult to positively distinguish wild yeast from pitching yeast without resorting to using selective media, one can be reasonably certain that one is selecting stable non-mutating pitching yeast if a colony is round.

 

[Good Ed]

Impressive stuff there, sac :thumb: I let Brewlab do that for me

 

[Paddy]

Thanks for the info everyome. I would love to get that technical about yeast not just for the beer but because im fascinated by the subject. Would love to set up a mini lab. But im years from that lol. Maybe when i retire ;-) Either way looks like some basic experimentation is in order. Thanks again for the hints n tips

 

[mike77]

I would suggest trying what brewtim is suggesting as an easy way to store yeast long term. I've just bought some ringwood yeast and if all works out I plan to freeze some. Basically I intend to freeze the slurry from the fermenter mixed with glycerin from Boots in plastic vials. When reusing the yeast I'll make a starter to prove its viable, if not nothing really lost and I'll pitch a pack of dry yeast.

 

[Paddy]

Thanks again for the help. Yeah this is what I am going to try first. Like you say worth a try, nothing to loose.

What is the purpose of the glycerin (lower freezing temp maybe?) and what ratio glycerin:yeast slurry would you use?

I thought freezing yeast killed it but I have obviously been misinformed...or maybe certain strains can handle it?

 

[StevieDS]

Alright paddy mate, how goes it?
Found this which I think you'll enjoy http://www.homebrewtalk.com/f128/glycer ... st-215319/
Apparently the glycerin prevents ice crystals destroying the yeast cells :thumb:
Stevie.

 

[Paddy]

Not too bad Stevie!

Thanks for that link. Only read the first page so far but looks like it has everything I need to know to get started. From what it says looks like it might be worth getting Whites book on yeast ranching too

 

[Dave1970]

My current brew is fermenting with Fullers yeast from a previous brew. It was frozen for 8 months as 50% yeast, 25% Water, 25% Glycerine. Pitched it into 1 litre starter a week before brewday. It took a couple of days to get going in the starter but no problem with it getting going in the brew itself.

 

[Paddy]

Wow Dave. Thanks for the real life example. Encouraging to know this definitely works. Cant wait to start harvesting now. Just need to work out getting a freezer :)

 

[Asalpaws]

Just tried freezing some WY Saison yeast as above used glycerine.

Seems the easiest option compared to slanting. Looking at the tubes, there are ice crystals in the top 2/3 but the yeast and glycerine have settled at the bottom so fingers crossed it will be viable! T

 

[Paddy]

Thanks for the pic asalpaws. Looks great. Better order me some vials and glycerin then.

 

[Asalpaws]

Make sure you get somthing with screw tops, rubber bungs + fermenting yeast = POP!

 

[evanvine]

Doesn't screw tops + fermenting yeast = BANG?

 

[Paddy]

Erm confused now as to what to get.... screw tops v no screw tops.... tho if Asalpaws is doing it already?

If there was an bashing head on table emo I would use it right now!

 

[saccharomyces]

Doesn't screw tops + fermenting yeast = BANG?

I leave the caps on screw cap culture tubes ajar while incubating cultures.