splitting white labs yeast

[Brycey]

I read somewhere that you can grow your yeast then split it several times !

I'm planning all grain#2 hopefully this weekend, one off pittsy's wheat beers. The white labs yeast adds quite a few quid to your brew so it would be good if i could split it 2 or 3 times to reduce the cost of my next couple of wheat beers.

Any guidance on this subject is appreciated.

Cheers
B

 

[DaveGillespie]

"Washing" and re-using the yeast seems to be the way to go rather than splitting between multiple brews. My next brew is my first Weiss and that will be getting WB-06 but the Belgian afterwards is WLP530 which will be washed and re-used for another Belgian.

I'll be having a practice run with the S-05 cake from the current brew first.

 

[brewtim]

Start your yeast, make a little bit more than you need, pitch your starter keeping some behind for a rainy brewday, simples!

Or as previously suggested - from your fermenting beer, topcrop or bottom crop.

 

[saccharomyces]

"Washing" and re-using the yeast seems to be the way to go rather than splitting between multiple brews.

As I have mentioned before, "rinsing" yeast with boiled water does more harm than good (proper yeast washing is an entirely different process). No professional brewer worth his/her salt rinses cropped yeast with boiled water. Yeast rinsing is a home brewer practice that is supported more by myth than science.

All one needs to do to harvest (a.k.a. "crop") pitching yeast from the bottom of a fermentation vessel is to leave enough green beer behind while racking to be able to swirl the solids back into suspension. The break material, hops, and dead yeast cells will quickly drop out of suspension, leaving mostly clean viable yeast in the liquid fraction. The liquid fraction should be decanted into sanitized container and stored in one's refrigerator. On brew day, the clear liquid fraction from the crop is decanted and replaced with fresh cool wort from one's batch before swirling the solids back into suspension. Yeast harvested and maintained this way can be repitched several times.

With that said, using a true top-cropping strain and cropping from the top at high krausen will result in a culture that can be repitched indefinitely. One should skim and discard the first head before taking one's crop, as the first head contains break material that is scrubbed from the wort by the yeast. The first head will also contain under-attenuating yeast cells.

 

[morethanworts]

Great post saccharomyces! I can't validate the science, but it sounds like sense to me.

Hope this isn't a thread hijack, but briefly if I may, any problems freezing top-cropped yeast with gelatin 50/25/25 or such like?

 

[Belter]

"Washing" and re-using the yeast seems to be the way to go rather than splitting between multiple brews.

As I have mentioned before, "rinsing" yeast with boiled water does more harm than good (proper yeast washing is an entirely different process). No professional brewer worth his/her salt rinses cropped yeast with boiled water. Yeast rinsing is a home brewer practice that is supported more by myth than science.

All one needs to do to harvest (a.k.a. "crop") pitching yeast from the bottom of a fermentation vessel is to leave enough green beer behind while racking to be able to swirl the solids back into suspension. The break material, hops, and dead yeast cells will quickly drop out of suspension, leaving mostly clean viable yeast in the liquid fraction. The liquid fraction should be decanted into sanitized container and stored in one's refrigerator. On brew day, the clear liquid fraction from the crop is decanted and replaced with fresh cool wort from one's batch before swirling the solids back into suspension. Yeast harvested and maintained this way can be repitched several times.

With that said, using a true top-cropping strain and cropping from the top at high krausen will result in a culture that can be repitched indefinitely. One should skim and discard the first head before taking one's crop, as the first head contains break material that is scrubbed from the wort by the yeast. The first head will also contain under-attenuating yeast cells.

Chris White advocates 'rinsing' in the yeast book pg168. Is it really a myth?

 

[brewtim]

Chris White advocates 'rinsing' in the yeast book pg168. Is it really a myth?

Isn't rinsing the same technique only using water or acid rather than the beer it was fermented in?

 

[rpt]

Chris White says to use sterile water. saccharomyces' point is that boiling water in the kettle doesn't sterilise it.

I suspect there are a lot of practices that homebrewers do that are not ideal, but most of the time we get away with it.

 

[saccharomyces]

Great post saccharomyces! I can't validate the science, but it sounds like sense to me.

Hope this isn't a thread hijack, but briefly if I may, any problems freezing top-cropped yeast with gelatin 50/25/25 or such like?

While I use ajar slants for long-term yeast storage, I see no problems whatsoever with freezing top-cropped yeast. Top-cropped yeast is very healthy and very clean. You just need to autoclave (pressure cook) any water that you plan to use. Pressure cooking the water at 121C for 15 minutes will render it absolutely sterile.

 

[saccharomyces]

Chris White advocates 'rinsing' in the yeast book pg168. Is it really a myth?

I believe that most people are taking what Chris said out of context. If I recall correctly, he does not advocate the practice when yeast is being cropped merely to be repitched. There is an advantage to separating the yeast cells from everything else if one intends to freeze yeast just as there is advantage to separating yeast cells from everything if one intends to freeze dry yeast.

With that said, rinsing yeast with boiled water just for the sake of separating it from the break and hops is a bad practice. First off, boiled water is not sterile. One must autoclave (pressure cook) water to render it absolutely sterile. Secondly, the pH of water is significantly higher than that of green beer. Lastly, the alcohol that reduces the viability of the yeast culture over time also keeps wild microflora at bay. Yeast takes over a batch of wort by consuming all of the oxygen, lowering the pH, and producing alcohol. Replacing the green beer with boiled water not only removes the force field that the yeast built for itself, it can also introduce spores, which can now germinate and feast on dead yeast cells because we have removed the yeast's force field.

In closing, many home brewers confuse yeast rinsing with proper yeast washing. Yeast washing is a technique that brewer's use as a last ditch effort to clean up an infected crop. The solution that is used for proper yeast washing has a very low pH. Lowering the pH kills most wild bugs, but it can also significantly reduce the viability the yeast culture.

 

[Belter]

Chris White says to use sterile water. saccharomyces' point is that boiling water in the kettle doesn't sterilise it.

I suspect there are a lot of practices that homebrewers do that are not ideal, but most of the time we get away with it.

I don't think this was implied. He said 'proper yeast rinsing is a different process' not just use Sterile water instead.

Also if you're going to freeze yeast you need to use glycerine so as not to rupture the cell walls. Never freeze yeast on its own.

 

[Belter]

Chris White advocates 'rinsing' in the yeast book pg168. Is it really a myth?

Isn't rinsing the same technique only using water or acid rather than the beer it was fermented in?

It's using water. Acid washing is different again. You can use phosphoric acid to lower the PH and kill bacteria but leave the yeast intact. Albeit in a less healthy state.

 

[dennisking]

Over the years I have tried most methods, splitting at the start, top cropping and re-using slurry. When re-using slurry I have always used boiled bottled water with no problems. Over the last couple of years I have been using the yeast from a local brewery. The head brewer has told me in the 3 years he has worked there they always re-use the yeast and never rinse or wash and to his knowledge never have in the previous 30 years. They have twice been voted CAMRA supreme champion.

 

[saccharomyces]

Also if you're going to freeze yeast you need to use glycerine so as not to rupture the cell walls. Never freeze yeast on its own.

Glycerine (a.k.a. glycerol) serves as a cryoprotectant. It prevents the formation of ice crystals inside of the cells walls.

 

[saccharomyces]

Over the years I have tried most methods, splitting at the start, top cropping and re-using slurry. When re-using slurry I have always used boiled bottled water with no problems. Over the last couple of years I have been using the yeast from a local brewery. The head brewer has told me in the 3 years he has worked there they always re-use the yeast and never rinse or wash and to his knowledge never have in the previous 30 years. They have twice been voted CAMRA supreme champion.

Bingo! I have always directly repitched cropped yeast. I tend maintain sizable yeast bank; therefore, I only repitch if I have no bank maintenance to perform.

 

[Smiddylad]

Sorry guys, if I’m going off topic a little.

Saccharomyces how many yeasts do you have in your bank? I do all my purchasing online, so I tend to bulk buy as it’s cheaper and easier to do it that way, which is a bit of pain when it comes to liquid yeast as the shelf life is not that great. To get around this I’ve decided to start a yeast bank. I was just gonna keep my yeast bank small to around 5 or 6 yeasts as I have heard that having a large yeast bank is a hobby in itself. How often do you re-culture your yeast on new slants, is it every 6 months?

Getting back on topic, my approach it to culture a fresh slant from the dregs of a White labs vial. I’m hoping this should save me a lot of money going forward.

 

[HLA91]

I have looked at liquid yeasts but didn't want a fridge full of bottles or messing around reclaiming yeast, I found this on JBK which is quite useful and only requires 1 small bottle in the fridge and involves splitting the starter instead of reclaiming.

Here's what I'd do. You'll only ever have 1 or 2 bottles of each yeast strain in the fridge.

1) Buy 6 330ml bottles of mineral water from a supermarket. Buy a 1 litre mineral bottle. Total cost £3.
2) One week before brewday, make a 3.5 litre starter in a demijohn. Pitch the liquid yeast once the wort / malt extract mixture has cooled.
3) Cover the demijohn's cap with foil (NOT an airlock). Give it a good shake every now and then to drive out the CO2 which inhibits oxygen intake and therefore yeast reproduction.

4) Two days before brewday, pour away the beery stuff on top leaving about 1.5 litres of yeast and beer.
5) Give the demijohn a vigorous shake (you might need to stir with the end of a sterilised, long plastic spoon if the yeast is packed down tightly on the bottom).
6) Sterilise a funnel.
7) Empty one of the 330ml mineral bottles and the 1 litre bottle.
8) Pour the yeasty mixture into the 330ml bottle before the yeast starts settling.
9) Pour the remainder into the 1 litre bottle.

10) Pitch the 1 litre bottle on brewday and reculture from the 330ml using another malt extract or wort based yeast starter on the next brewday when you want to use that yeast strain.

So then you use the small bottle to make another demijohn starter a week before brewday and then repeat.

 

[saccharomyces]

Sorry guys, if I’m going off topic a little.

Saccharomyces how many yeasts do you have in your bank? I do all my purchasing online, so I tend to bulk buy as it’s cheaper and easier to do it that way, which is a bit of pain when it comes to liquid yeast as the shelf life is not that great. To get around this I’ve decided to start a yeast bank. I was just gonna keep my yeast bank small to around 5 or 6 yeasts as I have heard that having a large yeast bank is a hobby in itself. How often do you re-culture your yeast on new slants, is it every 6 months?

I currently have ten cultures in my bank, two of which I pure-cultured (plated) from bottle-conditioned beers. I used to have over thirty different cultures in my bank before I took a long hiatus from the hobby.

Maintaining a yeast bank does in fact become a hobby unto itself. I am trying to limit my bank to about twelve cultures this time around, as I usually like to reculture within twelve months (six months is better).

I have started to collect really expensive cultures from major yeast culture collections. The only expensive yeast culture that I had in my old bank was NCYC 679 (my all-time favorite lager yeast), which I obtained directly from the NCYC. Unless one is willing to shell out the really big bucks for a live culture on slant, one usually receives cultures from the NCYC in lyophilized (freeze dried) form in glass ampules (I purchased NCYC 679 in lyophilized from the NCYC). I am currently working with a culture that was deposited in a culture collection almost seven decades ago. This culture originates from a defunct Northern European brewery that dates back to the beginning of the seventeenth century.

In closing, the true beauty of learning basic yeast management is that one is no longer tied to the yeast cultures that one can acquire through the home brew trade in dried or liquid form. Sure, there is an initial cash outlay in labware (nichrome loop, spirit lamp, screw cap culture tubes, and petri dishes) and an investment in time spent learning basic aseptic technique, but yeast effectively becomes free from that point forward. One can literally take a real ale sample at a pub, plate it for "singles," and grow a culture large enough to pitch without having to worry about if the sample taken at the pub was clean. It plated my first Ringwood culture from a hydrometer sample in 1994 (long before Wyeast or White Labs carried it). I can assure you that the hydrometer was not sanitized before the brewer took his reading.

 

[Smiddylad]

Impressive, it sounds like you know your stuff. What are the benefits of NCYC 679 over a generic lager strain and why was it expensive. I find yeast fascinating, but for me it’s not really a case of collecting obscure or expensive yeast (at least for now), but more of a case of easy access. I can’t really buy liquid yeast in bulk and my local homebrew shops are, to be honest, not very good. Their seems to be a common practice (in the north west of England at least) of storing yeast and hops out on the shelves instead of refrigerating them, which is a concern to me. They also don’t stock liquid yeasts, so my options are limited to buying online. So far I have banked WLP002 and 005 and I hope to bank a lager yeast (not sure which one yet), the Weihenstephan strain and possible a Belgian strain, maybe. I have yet to culture any for a beer yet, looking forward to my first effort though, I shall be rather pleased if I pull it off and brew a good beer.