Splitting A Wyeast Smack Pack

[Florian]

Thanks for the great info Tony, have just ordered a set of 100 7ml vials from the same supplier. I figured that 7ml will be enough, it would just take a bit longer, and if not I could always take two or three vials to build up a starter. I also ordered a 100ml baby Erlenmayer for $5.00 to add to my collection.

BTW, did you notice that the vials you use come sterile? So unless you re-use them, there is no need to boil them first. Just open, fill, and close again, should be as sterile as it can get in a home brew setup.
Obviously, when re-using, you would have to sterilise them again by boiling or similar.

Florian

 

[sama]

Great method! I presume the same method applies for 35ml white lab vials?> Swirl tube,keep two vials @ 10ml a vial,grow remaining 15ml yeast in 150ml of wort,step it up with 1 litre of wort,pitch when appropriate.

 

[Wolfy]

Great method! I presume the same method applies for 35ml white lab vials?> Swirl tube,keep two vials @ 10ml a vial,grow remaining 15ml yeast in 150ml of wort,step it up with 1 litre of wort,pitch when appropriate.

Given that they say 1 Vial is 'appropriate' for 5US gallons, I'd pitch the remaining 15ml of fresh yeast directly into a 2L starter and go from there, there should be more than enough viable yeast viable cells to need to mess around with smaller steps, and the lack of sugars and nutrients in the smaller starters may actually harm the yeast, or at least not allow for any resonable growth.

 

[sama]

Ive seen stated that a WL vial is equivalent to a pint starter (570mls),does this meen, theoretically a third could be pitched into 1000 mls of wort ,and used for a single 10.40 odd batch of beer.. Does this seem correct?

 

[Wolfy]

Ive seen stated that a WL vial is equivalent to a pint starter (570mls),does this meen, theoretically a third could be pitched into 1000 mls of wort ,and used for a single 10.40 odd batch of beer.. Does this seem correct?

I'm not sure if that comparison is correct or not, but I thought both Wyeast and WhiteLabs packs contain the same amount of yeast (about 100billion cells).
Chris White, has said (on the various Brewing Network podcasts) that (essentially) if you pitch a full vial into a starter less than 2L you really should not expect any (or minimal after 24h) change in cell count, smaller starters only help increase the yeast health not numbers.
Hence, my suggestion of a 2L starter was based on that and the assumption that with 1/2 a pack, you'd get cell growth of ~3 times (~150billion cells) which puts you right where you want to be for a single batch of normal gravity beer.
But there are so many fundamental assumptions made in terms of yeast age/cell count, conditions/nutrients in the wort, aeration etc that you'd probably not notice a difference using 1 or 2L starter anyway.

 

[Gopha]

Hi, Thanks Tony for the great info. I jumped on the recommended Web page and found the product referred to i.e. 30ml conical sample containers.
They are listed as being sterile so here is my question is it a waste to re-sanitise them by boiling, when you have a choice of labelled or unlabelled containers, the labelled containers would be most usefull.
I have asked the question elsewhere from folks that regularly use sample jars for QA testing and the consensus is that they are sterile for up to two years - Cheers

 

[Florian]

Gopha, as you said, they are sterile, so just use them as they are. Just don't let them sit open for too long before and after you fill them.

Have just ordered myself a bag of 100 10ml vials from a different supplier, they come sterile too. also got a 5000ml Erlenmeyer which I can't wait to put to use.

 

[Gopha]

Hi, At room temp say 22C, if i have smacked my yeast pack and given it a good shake, how long should I leave it before harvesting part of the it and pitching into starter? Do not wont mini grenades in the fridge- Cheers

 

[Pennywise]

Hi, At room temp say 22C, if i have smacked my yeast pack and given it a good shake, how long should I leave it before harvesting part of the it and pitching into starter? Do not wont mini grenades in the fridge- Cheers

The pack itself should explode, the time it takes to swell can vary, depending on the age of the pack. I think they say wait 24hrs for each month past it's package date. But really you don't need to wait till it's fully swelled before pitching, so long as it's swelled a bit you know it's active.
Once pitched into a starter, if I'm going to store some stubbies of yeast from it I just wait a week for it to ferment out, you should take a hydro reading though to make sure it's fermented out.

 

[Synthetase]

The first is to be as clean and sanitary as you can. Tony mentions that he splits up his packs across some test tubes - if I were using this method what I'd do is place a small amount of water in the test tubes and then put them in a pressure cooker or autoclave for around 20 mins before I used them - allowing them to cool first of course. This would come close to sterilising them.

More than close, an autoclave will definitely sterilise. 121 degrees Celsius for 15 minutes at 101 kPa is the standard autoclave run for sterilising equipment/growth media, etc.

The second would be the viability/mutation of yeast stored as a slurry at "fridge" temperatures for any great length of time. I don't have a lab where I could analyse this first hand so I'm simply going off what the yeast production companies recommend (Wyeast and White Labs). Viability is probably easy to live with, but mutations could/would change the characteristics of the yeast. Again, I'm simply repeating info that I have heard - not going off my personal experiences.

Mutations occur primarily due to (a) direct damage to DNA from external influences such as ionising radiation (X-rays, etc) and mutagenic chemicals (benzine, etc); and (b) DNA copy and repair errors made by the cells themselves. Now since the yeast is not growing in the fridge it's not going to be doing much in the way of DNA copying and it's not really exposed to mutagens, so I don't see it being a problem.

 

[Thirsty Boy]

More than close, an autoclave will definitely sterilise. 121 degrees Celsius for 15 minutes at 101 kPa is the standard autoclave run for sterilising equipment/growth media, etc.


Mutations occur primarily due to (a) direct damage to DNA from external influences such as ionising radiation (X-rays, etc) and mutagenic chemicals (benzine, etc); and (B) DNA copy and repair errors made by the cells themselves. Now since the yeast is not growing in the fridge it's not going to be doing much in the way of DNA copying and it's not really exposed to mutagens, so I don't see it being a problem.

The mutations being referred to are generally going to be what is known as "petite mutants" or more accurately as respiratory deficient mutations. They plate up as smaller tighter little colonies. They have something wrong in the mitochondria (I cant remember exactly what to be honest and can't be buggered going to look it up) and they ferment and produce flavor characteristics differently to non RD yeast. Stressed, low viability low vitality yeast are far more likely to throw RD mutants in their decendant generation. Not too bad an issue if you just grow up a culture, use it and discard, you might notice a little drift in character. But if you plan to repitch the yeast multiple times.... Then it might well become an issue.

 

[Synthetase]

Ah yes, the ol' 'small colony variant'. How I lothe thee.

Interestingly, given they are strict anaerobes, I would expect them to be well and truly out-competed in a well-aerated starter culture and therefore be a tiny minority of the total number of pitching cells, thus having little final impact. Of course you could always streak for single colonies but that's a whole other kettle of yeast.

 

[MaltyHops]

here are the 3 freshly filled tubes (left) and other older ones of varying strains on the right that have settles out in the fridge
...
some older tubes..... the 1469 is 14 months old and will be slow to start but will fire no problems.
...
any questions please ask!

cheers

Hi Tony,

+'s on thanks for posting this ... I've just done a smack pack split last night
and now have a few tubes from the pack, a few inoculated slants that hopefully
will take as well as a Mystery Belgian bubbling along quite nicely

Anyway, was wondering whether it would be worthwhile adding nutrients to the
tubes of divided smack pack to help extend their viability. I was thinking of using
the unused dry yeast packs from kits that I'm now ending up after boiling them
first.

Also, when using killed yeast as nutrients, can the packet be boiled unopened and
then sprinkled into the tubes, or do the dry yeast need to be boiled in water and
then added?

Regards,
Tom.

 

[praxis178]

Ah yes, the ol' 'small colony variant'. How I lothe thee.

Interestingly, given they are strict anaerobes, I would expect them to be well and truly out-competed in a well-aerated starter culture and therefore be a tiny minority of the total number of pitching cells, thus having little final impact. Of course you could always streak for single colonies but that's a whole other kettle of yeast.

Just read the streaking link, and had a look in my workshop (where I keep everything that might one day be useful), for the following: Autoclave [check], microscope (Olympus bino research job)[check], bunsenburner [check]...... hmmmm looks like the yeast lab is just looking for a room to exist in now......

I've been lugging the autoclave around from house to house now for the better part of a decade, and the microscope cost (used) US$1200 nine years ago.... Gee home-brewing can become an expensive hobby can't it?

 

[Acasta]

So tony does double batches.
If I wanted to apply this to my single batch process, would I be ok with splitting the yeast 4 ways and only using a 1L starter?
I used Mr. Malty calc, and it says that 1 pack is needed with a 1.33L starter, when set on "intermittent shaking". So is it still possible to use 1/4 per starter?

Beersmith2 is telling me I need a started of 2.93L using 2 packs of yeast. Im confused.

 

[Steve@PMF82]

So tony does double batches.
If I wanted to apply this to my single batch process, would I be ok with splitting the yeast 4 ways and only using a 1L starter?
I used Mr. Malty calc, and it says that 1 pack is needed with a 1.33L starter, when set on "intermittent shaking". So is it still possible to use 1/4 per starter?

Beersmith2 is telling me I need a started of 2.93L using 2 packs of yeast. Im confused.

It can be a bit of a guessing game the old yeast.
IMO i would go by MR Malty calculator, i have had great results using it.

This might interest you as well, its a Beersmith article, most of the info taken from the Yeast book funnily enough.

Edit link : http://www.beersmith.com/blog/2011/01/10/y...ng-beer-part-2/

I use the charts in conjunction with mr malty for measuring my actual yeast slurry, from farming /starters.
Also good for if you are restarting a small amount of washed yeast to more accurately guesstimate your % of live yeast in given sample.
You can then use the charts in the Beersmith article to work out your inoculation rate and growth rate, get out your own calculator and work out how many yeast cells you have after growing your starters ect.

hope that makes some sense

 

[Wolfy]

So tony does double batches.
If I wanted to apply this to my single batch process, would I be ok with splitting the yeast 4 ways and only using a 1L starter?
I used Mr. Malty calc, and it says that 1 pack is needed with a 1.33L starter, when set on "intermittent shaking". So is it still possible to use 1/4 per starter?

Beersmith2 is telling me I need a started of 2.93L using 2 packs of yeast. Im confused.

If you have a very fresh pack of yeast (only a week or so after manufacture) you could most likely pitch even 1/4 of a pack directly into a 1.33L starter and end up with about the same cell count as pitching the full pack.
However, if your pack is older (which is most likely if you live in Australia) you might find it better to step the starter (pitch the 1/4 of a pack into a smaller starter before pitching that starter into the final one).

Recommended starter sizes/pitching rates can vary a great deal, even published information suggests pitching rates that can be 10x different.
The MrMalty calculator is based on the 'industry standard' pitching rates that is taught to commercial brewers, and much research to determine yeast growth when new/fresh packs/vials of yeast are pitched directly into the starter. However since you are splitting your pack applying the MrMalty calculations directly to your scenario makes things a little more difficult and you need to make more assumptions, however if you come close to what is suggested, you'll likely be in the same ball-park and not have to worry.

 

[Acasta]

What type of simple method would you recommend for a beginner doing 20L singles.

 

[Wolfy]

What type of simple method would you recommend for a beginner doing 20L singles.

The exact size depends more on your starter containers than anything else, but a 250-400ml first step, then a 1.25-2L second step would work fine with an older split-pack.
If you need more info on starter containers, and making the starter hopefully this answers most questions: http://www.aussiehomebrewer.com/forum/inde...showtopic=54900

 

[Steve@PMF82]

Wolfy is on the money for sure.

I will give this example anyway.

Smack pack - 2monts old

54% viability

We will say 50 billion cells, split 4 ways = 12.5 billion cells.

1048 ale , 20L = 178 billion cells needed

1 billion cells into a liter is the same as 1 million cells per milliliter.

SO - we would have 25 mill cells per ml, if you went straight into a 500ml starter.
Giving you a growth rate of around X 3 (maybe X 4 if your shaking often during growth phase) : 3 X 12.5 billion = 37.5 billion cells, so we will say you now have 40 billion because you shook it often

Let this ferment out, chill , let yeast settle, decant liquid, let the yeast come back to room temp or same temp as new wort.

If you added this to 1.5 L starter with shaking swirling during growth phase you could get the same growth rate again X 3 or 4
Which will put you close enough to where you want to be.

Obvioulsy these numbers will change depending on the age of your split smack pack over time.
Mr Malty will tell you what % viabilty you have.