Splitting liquid yeast packs (in Pictures)

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Wolfy

Splitting liquid yeast packs (in Pictures)

Post by Wolfy » Sat Sep 15, 2012 5:05 pm

Splitting liquid yeast packs is an easy and cost-effective way to split, share and save yeast
The information here is my take on the technique made popular by AHB forum member Tony some years ago, (see here and here).

Advantages of splitting yeast packs (this way):
  • Simple and easy.
  • Minimal cost or equipment outlay.
  • Saved yeast is 'virgin' or 'generation 0' (hence should not be contaminated or contain mutations).
  • A store-purchased packet of yeast can be used for multiple batches of beer.
  • Stored 'splits' take up very little room.
  • 'Splits' are easily swapped and shared with others.
Disadvantages of splitting yeast packs (this way):
  • Minimal cost for equipment (vials, test-tubes or sample-jars).
  • Starters are required since the yeast-pack is split multiple times.
Equipment required:
Image
The only specialty equipment required (compared to using a full yeast-pack) are some vials to store the 'split' yeast in (see note at end of this post).

Step 0: (optional)
If using a Wyeast pack (as per the pictures here), smack the pack and wait for it to swell, this provides more liquid to split and 'revives' the yeast which should mean it will be viable for a longer period when stored.

Step 1:
Sterilize the sample containers, if they are supplied sterile ensure that the caps are not opened until you are about to use them.
If re-using vials, an autoclave/pressure cooker is the best way to sterilize them, otherwise try the Tyndallization process or simply boiling them for a time.

Step 2:
Working in your draught-free, clean and sterile as possible yeast 'laboratory', wipe the yeast-pack and scissors with alcohol and carefully snip the top-corner of the pack.
Image
Step 3:
Pinch the snipped-corner to form a funnel and carefully decant the yeast-liquid into the sterile vials.
Image
Step 4:
The size and number of 'splits' you make depends on the package size (see note below), how fresh the pack is, how many samples you want to save/swap, and the size of your vials. Here I am making 4x 12ml 'splits'.
Image

Step 5:
Label the vials (and optionally seal the caps using parafilm/tape).
Image

Step 6:
Store 'split' samples of yeast as cold as possible in the fridge (but do not freeze it), after a short time the yeast will settle.
Image

Step 7:
Swapping yeast 'splits' with other brewers allows you to obtain and use other yeast-strains to use without additional expense.
Image
('Splits' stored in 10, 12 and 30ml vials are shown above)

This technique works equally well for WhiteLabs vials - which contain about 35ml of liquid and 100billion cells.
Wyeast Activator packs (shown in pictures here) should have about 100billion cells in 125ml of liquid.
Wyeast Propegator packs should have about 50ml of liquid and 25billion cells.
In theory small samples of dry-yeast can be split, saved and propagated, however most people do not consider such a technique cost or effort effective and so it's generally suggested that the 'correct' amount of dry yeast is used.

Note about vials, sample-jars or test-tubes
Most people use laboratory-type sample containers, vials or test-tubes but most any container of suitable size and material can be used.
Vials made from autoclavable polypropylene means that they can be heat re-steralized and re-used.
I like to use the 15ml test-tube type containers shown above, but any vial/test-tube/sample-container from about 7ml up to 30 or even 50ml can be used.

To determine the number of yeast-cells in the split and remaining in the pack
First estimate calculate the number of viable yeast cells based on manufacture date (via MrMalty calculator).
Divide this number according to the volume of your splits and yeast-pack type.
Eg: My 1 month old Activator pack should have about 75billion viable yeast cells in 125ml of liquid, hence the 12ml 'splits' should have about 7.5billion cells each, and the remaining 80ml should contain about 48billion cells. The 48billion cells remaining in the pack is more than enough to pitch directly into a 'full size' starter.

Storing 'splits'
Yeast 'splits' should be stored in the fridge at as cold temperature as possible (but not frozen) and should be viable for at least 6 and up to 12 months.
In theory it should be possible to replace some/most of the wort/nutrient liquid with sterile-glycerin and freeze the 'split', which should (in theory) greatly prolong the storage time (by years) - however I've not tested this theory yet.

Using 'splits' and split-packs
Due to the smaller number of yeast cells, a starter will always be required to grow enough yeast to ferment a (standard volume, standard gravity) full batch of beer.
In the example shown in the photos here, I guessed/estimated that (after taking the 4x 12ml splits) I have about 80ml liquid and 48billion cells remaining in the pack. This is enough to pitch directly into a 'full size' 1.5L starter to produce somewhere around 150billion cells, which will then be pitched into 24L of 1.038 English Ale:
Image

When using the yeast from the saved 'splits', the only time it would be recommended to pitch the 'split' directly into a full volume starter is if they are are larger-volume (30-50ml) and very fresh.
If the saved 'splits' are smaller in volume (like my 12ml 'splits' shown here) or older (more than 1 month old) a stepped-starter would be recommended in order to grow pitchable quantities of yeast.
The size and number of steps required will depend on how much viable yeast is estimated to remain, which in-turn depends on the volume and age of the 'split'.
Essentially what this yeast splitting technique is doing is swapping buying more/new/fresh yeast-packs for making (stepped) starters, so a good understanding of starters and stepped-starters is required before attempting this technique - however there is no reason anyone could not 'split' the first (and every) liquid yeast-pack that they buy.
Last edited by Wolfy on Sun Sep 16, 2012 3:52 am, edited 4 times in total.

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Beer O'Clock
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Re: Splitting liquid yeast packs (in Pictures)

Post by Beer O'Clock » Sat Sep 15, 2012 8:09 pm

Great post Wolfy.

Now do one for White Labs :wink:
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Wolfy

Re: Splitting liquid yeast packs (in Pictures)

Post by Wolfy » Sun Sep 16, 2012 1:47 am

Beer O'Clock wrote:Now do one for White Labs :wink:
I'd like to do that, but the reason why it's taken me so long to do this is because don't usually buy either White Labs or Wyeast packs, BrewLab slants are about the only other liquid yeast I have purchased in years (since it's not usually available here). I have so many yeast-strains stored in the fridge (most on slants) or freezer (under glycerine) and swap with others for new strains, that it's been some years since I had a new-pack to take photos of. Unfortunately, there are no local shops that sell White Labs vials so (unless White Labs or someone sends me a sample vial to take photos of) it's not likely to be something that I'll do ... however, it's the same process, just with less liquid to work with - so it might be worth using some cooled-sterile (or boiled) water if larger sized vials are used for storage.

After splitting the 4x12ml vials and pitching the remaining (approx 80ml) yeast-slurry into a 1.5L starter, the starter was grown on the stir-plate for a 36h then left to ferment/settle for 12h before taking this photo:
Image
The gravity is about 1.005, it smells/tastes like it should and visually there is a good amount of yeast (somewhere around 150billion cells +/- 50%) so it should be ready to be pitched (tomorrow) into a 24L batch of 1.038 English Ale.
... the splits are in the fridge ready for future use or swapping.

jimp2003

Re: Splitting liquid yeast packs (in Pictures)

Post by jimp2003 » Sun Sep 16, 2012 10:39 am

Great post Wolfy! =D>

I tend to buy Whitelabs vials but might give Wyeast a try and give this a go. I can see that pouring from the Whitelabs vials might be a bit more fiddly particularly if you are using a strain that tends to clump together (WLP002 for example).

cellone

Re: Splitting liquid yeast packs (in Pictures)

Post by cellone » Tue Sep 18, 2012 11:38 pm

That looks pretty straight forward. I'll give that ago once I find out how to measure yeast and make a starter.

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Re: Splitting liquid yeast packs (in Pictures)

Post by Jim » Wed Sep 19, 2012 8:02 am

Like it. Nice only, Wolfy! :=P
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Re: Splitting liquid yeast packs (in Pictures)

Post by ajclarkson » Fri Oct 26, 2012 10:11 am

Excellent thread, Wolfy!

I'm going to be trying this in the near future, as I read more about rinsing yeast it made more and more sense to me that you could just split the yeast beforehand and ensure a healthier yeast. Then low and behold I come over here to ask some questions and there's a brilliant picture how to already.

So to take this to the next level, and maybe I'm being too thrifty here, would it be possible to split the starter after stepping up, to create even more vials of the original yeast?

So I step up a 12ml vial for example, get to a pitchable rate, allow the yeast to settle and decant off most of the starter wort. Then shake to mix the yeast back into the remaining liquid, and pour this into some more vials?

Just thinking if this works, when I get down to 1 vial remaining of a particular strain, I could in theory make up another 4+ vials from that one, and proceed as normal?

If that works, I might be on my way to a healthy yeast library starting in the not too distant future!
Adam

Fermenting: AG#15 - Dubbel - Oh, Seven?
Conditioning: AG#14 - Pale Ale 3 (Challenger & Mt. Hood)
Drinking: Out! :(
Up Next: Oatmeal Stout, Hefe
Year To Date: 165 pints | Total: 775 pints

My Setup: Electric BIAB with a Dual Purpose Heat Exchange / Cooler

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Re: Splitting liquid yeast packs (in Pictures)

Post by ajclarkson » Fri Oct 26, 2012 11:28 am

Actually to be honest, the more I read your slanting stickies, the more I think I'm tempted to go that way, and just buy a white labs vial, culture from it, pitch the rest into my brew and then step up individual colonies from that slant in future.
Adam

Fermenting: AG#15 - Dubbel - Oh, Seven?
Conditioning: AG#14 - Pale Ale 3 (Challenger & Mt. Hood)
Drinking: Out! :(
Up Next: Oatmeal Stout, Hefe
Year To Date: 165 pints | Total: 775 pints

My Setup: Electric BIAB with a Dual Purpose Heat Exchange / Cooler

jampot

Re: Splitting liquid yeast packs (in Pictures)

Post by jampot » Fri Jan 04, 2013 7:36 am

I now make 50 ltrs of beer at a time. 2 x 25 ltr fv's. What would be the best way to divide a single smack pack between the 2 fv.

Stoat on a rope

Re: Splitting liquid yeast packs (in Pictures)

Post by Stoat on a rope » Fri Jan 04, 2013 1:17 pm

Think ill give this a go, nice work!

Wolfy

Re: Splitting liquid yeast packs (in Pictures)

Post by Wolfy » Thu Jan 17, 2013 2:42 pm

jampot wrote:I now make 50 ltrs of beer at a time. 2 x 25 ltr fv's. What would be the best way to divide a single smack pack between the 2 fv.
If it was me I'd split the packs directly into a two starters starter (somewhere around 2L each, depends on the yeast/beer etc) put that on a stir plate for a day or so, and then pitch the yeast into your beer.

paulg

Re: Splitting liquid yeast packs (in Pictures)

Post by paulg » Thu Jun 06, 2013 8:01 pm

wolfy
you say you have used brewlabs slants and I see you are in Australia how long did they take to arrive and how did they survive the post .I am in greece and my post can take upto 3 weeks to arrive and have therefore been put off of liquid yeast until now
regards Paul

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