Reuseing yeast

[Oldbloke]

I had a batch that was slow to start fermenting last week. So I used a spare coopers satchel I had. I like to always have a spare in case of this sort of thing. Hasn't happened for a long time.

Need another spare satchel now. So, to do this after bottling I put about 150ml of the sediment in a sanitised glass  covered it in glad wrap and in the fridge. I intend to pitch this and save the satchel from the can.

 

My question is.

How long can I reasonably expect to keep this in the fridge? 

[Spursman]

I'm very new to reusing yeast slurry. In my research the general consensus was "about 2 weeks" if I remember correctly. 

[Classic Brewing Co]

I have only done it a few times too, but this is a useful article.

https://beercreation.com/should-i-store-beer-yeast-in-the-refrigerator/#:~:text=Generally%2C you want to use a yeast slurry,than about 6 months%2C less may be better.

Storing yeast slurry

As with many things in the brewing community, getting a clear definition of what ‘slurry’ means is difficult. For some it’s yeast suspended in liquid, for others it’s the yeast cake at the bottom of your fermenter from which we separate viable yeast from other trub. Whatever you define it as let’s agree that we are discussing the same thing here.

Generally, you want to use a yeast slurry solution as soon as you can, however, commercial brewers can store their concoctions for many weeks or even months and still bring life out of them.

Make sure that you store your slurry in a refrigerator when possible, in an airtight container for no more than about 6 months, less may be better. If that’s not possible, then again store it as you would dry yeast in a dark and cool place again in an airtight container. You can feasibly do this for around a month. In both cases, you will have to introduce your harvested yeast into your wort in the form of a starter for the best results.

[Shamus O'Sean]

54 minutes ago, Oldbloke said:

I had a batch that was slow to start fermenting last week. So I used a spare coopers satchel I had. I like to always have a spare in case of this sort of thing. Hasn't happened for a long time.

Need another spare satchel now. So, to do this after bottling I put about 150ml of the sediment in a sanitised glass  covered it in glad wrap and in the fridge. I intend to pitch this and save the satchel from the can.

 

My question is.

How long can I reasonably expect to keep this in the fridge? 

For 150ml you want to use it within a month in my experience.  Yeast starts to die off over time.  You need about 200 billion healthy yeast cells in a typical 1.040 23 litre batch.  If your slurry has about 1.5 billion healthy cells per ml, you have 225 billion healthy cells.  You will still have enough healthy cells after about 4 weeks.

[Malter White]

58 minutes ago, Shamus O'Sean said:

For 150ml you want to use it within a month in my experience.  Yeast starts to die off over time.  You need about 200 billion healthy yeast cells in a typical 1.040 23 litre batch.  If your slurry has about 1.5 billion healthy cells per ml, you have 225 billion healthy cells.  You will still have enough healthy cells after about 4 weeks.

I don't know where you find the time to count them all. This is why I call you the guru.

[Classic Brewing Co]

35 minutes ago, Malter White said:

I don't know where you find the time to count them all. This is why I call you the guru.

Malter, does you mean you don't count them? 

[BlackSands]

I've had 6-week old kveik slurry kick into action in no time - but that's kveik of course.  Other 'normal' strains' might be getting a bit tired by six weeks, though if I remember rightly, years ago I'm sure I had some Nottingham stored away in a fridge for much longer than that which was still viable when I did finally get round to using it. 

[Malter White]

30 minutes ago, Classic Brewing Co said:

Malter, does you mean you don't count them? 

I've only got 10 fingers and 10 toes.

[Oldbloke]

OK. Thx gents. More or less what I expected. I do a brew about every 3 weeks so no issue.

 

I did it years ago but they were back to back.

[ben 10]

5 hours ago, Oldbloke said:

How long can I reasonably expect to keep this in the fridge?

I have done 3 months without issue, stored in the fridge under beer

[ben 10]

3 hours ago, Malter White said:

I don't know where you find the time to count them all

@Otto Von Blotto has done it

[Greenyinthewestofsydney]

5 hours ago, Shamus O'Sean said:

For 150ml you want to use it within a month in my experience.  Yeast starts to die off over time.  You need about 200 billion healthy yeast cells in a typical 1.040 23 litre batch.  If your slurry has about 1.5 billion healthy cells per ml, you have 225 billion healthy cells.  You will still have enough healthy cells after about 4 weeks.

Totally agree. Anything over 3 weeks and I build a new starter. This came after a full lager slurry crapped out on me and it was not much more than a month old. Once bitten twice shy as they say.

[Greenyinthewestofsydney]

1 hour ago, beach_life said:

@Otto Von Blotto has done it

From memory @Otto Von Blotto counted them on an unhopped starter of mid 1030s OG and it was high cell rates after a month or so. Slurry with hops and a higher alcohol amount would lower that a fair bit.

[Oldbloke]

That sediment was put in the fridge on 16/1. Today is 24/1. So, just 8 days.

I had a big jar and nearly due to put a brew down so decided to get her started.

Using boiling water I sanitised the jar.

Put 2 heaped table spoons of LDME + 1 teaspoon sugar.

Added about 150ml boiling water and stirred.

Topped it up to about 400ml of cold tap water and added the sediment.

Checked and a bit hot at 33c. Too late, so just put in fridge for about 40 minutes.

Its now about 2 hours total. Looks great, smells better.  About an inch of froth on top.

Urrently on the kitchen bench & I'll put it in my fermenting fridge later. Abt 20c.

If alls well tomorrow morning ill put a Real Ale down.

 

[Oldbloke]

Well, at a bit over 3hrs it was yelling at me to shout it a beer.  So, I did. It went into a fv full of Real Ale and 500g of LDM + about 100g of corn syrup.

She'll be apples. Oops, sorry, beer. 

 

Bottle in about 9-10 days. Drink in about 4 months.