Splitting liquid yeasts without filling the fridge

[dean_wales]

Hi guys,

Following on from discussions in the other liquid yeast thread.

I have just brought a vial each of Whitelabs WLP002, WLP400 and WLP500 for some beers I have planned. The vials are tucked away neatly at the back of the fridge now.

I am a bit unclear on splitting and pitching. Although I understand Jim's method, if I did split each vial in 2 or 4 that would entail storing between 6 and 12 little bottles of wort in the fridge. That will never get approval!

I would like to split the vials over at least two brews for cost purposes but without filling the family fridge. Can I simply pitch half of the vial into a 2 litre starter and then recap the vial or do I risk infection? Would that starter then be OK for a 5 gallon strongish brew? Can I use regular pale spraymalt when making a starter for a Hoegaarden clone etc?

The expiry date isnt that long on the vial (2months) I probably wont use it all up until nearly chirstmas, how to I prolong their lives?!!

Thanks,

Dean.

[Texy]

Hi,
I,m far from an expect, but it seems to me that yeast is self reproducing and as long as it has enough food and the conditions are right it will last forever. Once you've bought I strain, you should never need to buy it again if you keep some back after every brew, and store it dormant in the fridge
An expert can chip in now and tell me where my theory is wrong

So whats wrong with spliting it into two, making sure it replicates itself to double the original volume (say), using one to brew and the other made dormant again by going back in the fridge ad-infinitum ?

Texy

[gunner]

I too am no expert but IMO you shouldn't use half a vial then recap.If you want to split the vial,pitch the whole vial into a 2L of dme light,once the starter has finnished,let it stand for 8-12 hours for the cells to restore their glycogen levels,put the starter in the fridge,once chilled decant most of the starter liquid.

Each vial has around 100 million cells,but by making a starter you have doubled the cell count to 200 million,a pitchable rate for 5G batch.So now you have the option of pitching that starter to 5G or splitting it into 2,and repeating the procedure with both splits when you brew.

If you wanted you could drain of the starter liquid once the starter has finnished,add another 4L of dme,and once that had finnished you would have 3 splits around 4 million cells.

Graham.

[InsideEdge]

You could just harvest the yeast from the bottles after you have brewed. Ready made yeast slant almost.

[Beer Belly]

I empted my white labs vial into a 2 litre starter, kept it in there for two days to grow it, sanitised the vial and refilled it from the starter. If I need to use it again I'll repeat the process.

[staplefordbill]

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.
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.

You could recover the yeast from the brew once it's finished fermenting, although you need to use it within 2 weeks so it's not much help if you have to wait longer than that. That's where the 330ml bottle comes in useful.

You can reuse the small and little bottles. I've done that and sterilised with VWP then filled with water and a Camden tablet (Leedsbrew's advice).

An American book I have says that yeast starts to mutate after 5 or 6 generations and can give off-tastes. Therefore there may be a limit to the number of times you can recover yeast. I'm not sure about this though as I haven't experienced it yet. I believe many brewers overcome this by acid washing their yeast (with phosphoric acid?)

[Deebee]

You could just harvest the yeast from the bottles after you have brewed. Ready made yeast slant almost.

Exactly what i do and it works perfectly:)

[Wolfy]

I would like to split the vials over at least two brews for cost purposes but without filling the family fridge. Can I simply pitch half of the vial into a 2 litre starter and then recap the vial or do I risk infection? Would that starter then be OK for a 5 gallon strongish brew? Can I use regular pale spraymalt when making a starter for a Hoegaarden clone etc?

The expiry date isnt that long on the vial (2months) I probably wont use it all up until nearly chirstmas, how to I prolong their lives?!!

The simplest and most elegant solution is - as you have suggested - is to simply use a portion of the yeast and then save the rest in the original vial. If you are careful the risk of infection is minimal (to non existent). However whenever you do not use a full pack of yeast (or if you use an old pack) you will need to make a starter in order to grow the correct amount of yeast to pitch into your beer (check MrMalty for the starter size, and even consider stepping the starter from a smaller volume first).

Saving/propagating from the original vial has the advantage that you are working with 'Generation 0' yeast (in it's most pure form from the factory), anything you do after that (such as making and splitting a starter) poses some risk of mutation or change. Especially if you have no room, there is no reason not to save some of the yeast in its original tube.

Regular spraymalt will make a fine starter, however you may like to consider decanting the spent beer and pitching only the yeast once the starter is ready.

The stored yeast will slowly die over time, however, the 'expiry date' is really the date for pitching it directly into your beer, so even 6 to 12 months after the 'expiry date' date there will be some viable yeast left. However the older the sample the less viable yeast you will have, so your sanitation, propagation and stater procedures become much more important - you can't just pitch the old yeast into your beer or even into a larger (2l) sized starter.

While there is nothing wrong with making a starter and splitting it into a number of bottles, or harvesting yeast after fermentation, either directly from the FV or from the bottle dregs, it's my personal preference to split the yeast as soon as the pack is opened. Split the fresh 'Generation 0' pack into a number of small test-tubes or vials, but this technique does require the purchase and preparation of small vials to hold the yeast, rather than just using the bottles you probably already have (but that also take up more room in your fridge).

[dean_wales]

Obviously one that everyone does differently!

Thanks Wolfy... I was beginning to run out of options and though I was the only one who considered splitting the vial a good option! I will likely only use each strain twice this year but would like to not have to buy them again as I am a cheapskate. I like the idea of maintaining the factory produced yeast in the manufacturers vial. It seems less risky as well as saving sapce and yeast generations.

So if ...

One week before brewday shake up the vial and pitch a third of it into a one litre spraymalt solution. Is this enough to make back up the yeast numbers equivalent to one vial?
A day or two before brew day tip off the "wort" and add one or two litres of fresh spraymalt to make up the true starter?
Pitch this starter leaving as much of the starter "wort" behind as possible so as not to affect style.

Is there some calculator that I can use to calculate yeast maths?!?! Am I missing something here?

Thanks,

[Wolfy]

One week before brewday shake up the vial and pitch a third of it into a one litre spraymalt solution. Is this enough to make back up the yeast numbers equivalent to one vial?
A day or two before brew day tip off the "wort" and add one or two litres of fresh spraymalt to make up the true starter?
Pitch this starter leaving as much of the starter "wort" behind as possible so as not to affect style.

Is there some calculator that I can use to calculate yeast maths?!?! Am I missing something here?

The MrMalty calculator is a great resource for determining starter sizes: http://www.mrmalty.com/calc/calc.html
However, it ONLY works for pitching yeast packs directly into a starter that goes directly into your beer, it does not work (directly) for stepped starters or for growing up starters from a small volume of yeast, but it will give you some idea of what you should be aiming for.

However when dealing with stepped starters and small starting volumes, its often easier to use the more general rule of thumb that the yeast cell density (in a starter) will max out at around 100million cells per ml (assuming that the original pitching rate was around 10million cells per ml).

The size starters you use, and how/if you step them up is really related to how much viable yeast you are starting with.
If you save only a part of the original vial, and it is some months old (especially past its use-by date), I'd suggest starting small and then using several steps to get to the final starter volume (something like 100ml, 400ml, 2l). Once the yeast has acclimatized to the wort it does not take long for it to reproduce (usually 12-24h if it is active and healthy), leaving it longer than that does not promote more growth (you are looking for cell growth not for it to ferment out the starter). So if you have a small sample of old yeast, pitch it into the small starter and hopefully within a couple of days you should see activity, step that up into the next size and wait another day or so, and then into the final starter and another day or so. Let the yeast settle out, put it in the fridge for a day or two, decant the spent starter and pitch only the yeast.