Reusing Freshly Harvested Yeast

[DoctorMick]

I'm going to reuse the yeast from my current brew in to my next one which I'll hopefully get on the day after I've harvested the yeast. From reading my yeast book and it seems to suggest that I don't need to make a starter as long as I use the slurry I've harvested within a week, does that sound right?

My process is going to be:

- Crash bool the beer for a day
- Rack beer in to bottling bucket leaving about 1l behind
- Mix the beejezus out of what's left in the fermenter
- Pour the mixed up trup in to two sanitized 1l jars
- Leave to settle for 10 mins
- Pour the yeast/beer off the trub in to another sanitized jar
- Put the yeast in the fridge
- On brew day bring the yeast up to pitching temp
- Bung the contents of one of the jars in to the brew

The other jar will stay in the fridge for another two weeks until the following brew but I'll make a starter for that one. Are there any obvious flaws in my process?

 

[MyQul]

Your right, if you are pitching within a couple of weeks, you don't need to make a starter.
The only change I would make to your process, point 5 and 6 you can leave out. I dont bother doing them. Just put the harvested trub straight in the fridge. If when you come to pitch it's settled out a bi,t and you've got some beer sitting on the top of the trub (which is what I usually find happens) just decant it off and pitch the remaining trub

 

[johnnyboy1965]

Your process is right, but you should always make a small starter (1li) just to prove the viability of the yeast.

 

[DoctorMick]

So I've decanted the yeast cake/trub from the fv into two 1l jars and it's been settling for an hour or so. I can see two distinct layers but I was expecting 3, am I just not looking hard enough or is it just that I'm impatient? Is half the jar really just trub? I know it's not that important as I'll be pitching the entire contents of one of the jars into my next brew but I'd like to understand what I'm looking at.

 

[MyQul]

I can see four layers

The first layer (from the bottom up) is heavier trub. The next layer up from the bottow with a very distinct line will be yeast and trub mixed together. The third layer will be yeast and beer mixed together.
The fourth layer is quite hard to spot. It's slightly easier to see in the left hand jar. From the top of the liquid down about 1cm there is a layer that looks slighly less milky than layer three. This will be beer with less yeast in it. The longer you leave it the clearer this layer will become as the yeast settles out and eventually you'll get a distinct layer of yeast sitting on the heavier trub. Especially if you put the jars in the fridge to crash

 

[JapanBrew]

That's a good amount of yeast. I'd split that again. You look like you've made four good batches. At least make 3.
It depends how you want to go but, if I were doing it, I wouldn't have let it settle that much.
But, if you're brewing soon like you said, just keep one out and pitch it straight in.

 

[DoctorMick]

All looks very different this morning...I still can't tell which later is the trub, the yeast and the spent wort tho! :lol:

 

[DoctorMick]

That's a good amount of yeast. I'd split that again. You look like you've made four good batches. At least make 3.
It depends how you want to go but, if I were doing it, I wouldn't have let it settle that much.
But, if you're brewing soon like you said, just keep one out and pitch it straight in.

Yeah, 1l jars were probably a mistake with hindsight. :lol:

 

[MyQul]

(From the bottom up again), Layer 2 has now compacated down some what. Layer 3, the yeast has started to settle out of the beer and you can now see a line of yeast sitting on top of layer 2. There's no longer a layer 4 as the yeast has properly began to settle out of layer three.
If you left it/crashed it. Layer 2 would probably compact down a bit further. Layer 3 would ger a bit thicker and the beer above would get clearer

 

[DoctorMick]

Ah so the thin white line is actually the yeast and the inch or so below it is just trub?

 

[MyQul]

Ah so the thin white line is actually the yeast and the inch or so below it is just trub?

The white line is purer yeast and the inch or so below is yeast and trub mixed together. Did you just rinse with water or just pour it into the jars straight from the FV?

 

[DoctorMick]

The white line is purer yeast and the inch or so below is yeast and trub mixed together. Did you just rinse with water or just pour it into the jars straight from the FV?

Straight in to the jar, wanted to keep the process as simple as possible. If I was so inclined, how would I get rid of the bulk of the trub?

 

[MyQul]

Straight in to the jar, wanted to keep the process as simple as possible. If I was so inclined, how would I get rid of the bulk of the trub?

You could rinse it with water.

Decant off the beer then put it into about 4L of boiled and cooled water in a 5L water bottle. Give it a good shake then wait 20 mins for most of the heavy trub to settle out. Then decant off the yeast that's in suspension into a couple of 2L water bottles. Then crash it for a couple of days in the fridge. Then decant off the water and put the yeast in 2L of starter wort and ferment out.
You said you were going to pitch everything (although I'd decant off any beer off the top). The trub wont do any harm and I would do this. I only rinse if I want to keep a strain for a while. After the starter has fermented out I split it into 4x500ml bottles an then store it away.

 

[JapanBrew]

The trub is a darker color... I mean colour.
Myqul is right. I wash to store but if your going right to a next brew, just pitch one jar. Then wash the other jar. The first sitting, 1 hour, is a tad long. 20 min will get most of the garbage settle to the bottom. The rest is beer and yeast. When you wash, you can first put it in the fridge for a day or two. Let it all compress. Boil a liter of water and let it cool to room temp.
The jar with yeast you put in the fridge Spray the lid with alcohol or starsan and then open and dump, decant, the beer. Add the chilled water and shake well. Let it sit for 20 min again. After 20 min. you'll see more trub at the bottom. The rest is yeast. Pour that into a new jar that had been boiled for at least 8 minutes and cooled. Then place back into the fridge. After a day or two, you can decant the water or just leave it. I decant so when I build a starter, I can just get mostly yeast.
Like myqul said, make a large starter and split it for later. But you do have a lot of yeast just from the picture I see. Don't pitch all of it. Over pitching can be bad. Up to 2 satchels is fine but what I see is more like 4!!

 

[DoctorMick]

You could rinse it with water.

Decant off the beer then put it into about 4L of boiled and cooled water in a 5L water bottle. Give it a good shake then wait 20 mins for most of the heavy trub to settle out. Then decant off the yeast that's in suspension into a couple of 2L water bottles. Then crash it for a couple of days in the fridge. Then decant off the water and put the yeast in 2L of starter wort and ferment out.
You said you were going to pitch everything (although I'd decant off any beer off the top). The trub wont do any harm and I would do this. I only rinse if I want to keep a strain for a while. After the starter has fermented out I split it into 4x500ml bottles an then store it away.

I was planning on keeping the second jar for another couple of weeks and use in the following brew so I might wash it. I suppose it depends on the answer to this question tho...is it better to use this harvest or harvest more from the next brew?

 

[DoctorMick]

The trub is a darker color... I mean colour.
Myqul is right. I wash to store but if your going right to a next brew, just pitch one jar. Then wash the other jar. The first sitting, 1 hour, is a tad long. 20 min will get most of the garbage settle to the bottom. The rest is beer and yeast. When you wash, you can first put it in the fridge for a day or two. Let it all compress. Boil a liter of water and let it cool to room temp.
The jar with yeast you put in the fridge Spray the lid with alcohol or starsan and then open and dump, decant, the beer. Add the chilled water and shake well. Let it sit for 20 min again. After 20 min. you'll see more trub at the bottom. The rest is yeast. Pour that into a new jar that had been boiled for at least 8 minutes and cooled. Then place back into the fridge. After a day or two, you can decant the water or just leave it. I decant so when I build a starter, I can just get mostly yeast.
Like myqul said, make a large starter and split it for later. But you do have a lot of yeast just from the picture I see. Don't pitch all of it. Over pitching can be bad. Up to 2 satchels is fine but what I see is more like 4!!

Thanks. So for this next brew should I just shake up the jar and chuck half of it in?

 

[MyQul]

I was planning on keeping the second jar for another couple of weeks and use in the following brew so I might wash it. I suppose it depends on the answer to this question tho...is it better to use this harvest or harvest more from the next brew?

I'd just harvest more from the next brew as the longer you keep it in the fridge the lower the viability becomes then you have to make a starter with it to 'refresh' it. But having said that two weeks is fine in the fridge. Much after that and you'd want to make a starter

 

[JapanBrew]

Thanks. So for this next brew should I just shake up the jar and chuck half of it in?

One jar might be ok. Unless it's a light beer like low 1.040. From the looks of it, you have a nice batch of yeast in both jars.

 

[johnnyboy1965]

All looks very different this morning...I still can't tell which later is the trub, the yeast and the spent wort tho! :lol:

This is exactly what your looking for. The thin white line on top of the trub is the yeast settling out. Above that is a mixture of liquid and yeast. Decant this liquid off into another jar and let it settle. This will give you your yeast. If youve missed it and the top layer is clear with a thick white line, just give it a shake and start again.

 

[DoctorMick]

I'd just harvest more from the next brew as the longer you keep it in the fridge the lower the viability becomes then you have to make a starter with it to 'refresh' it. But having said that two weeks is fine in the fridge. Much after that and you'd want to make a starter

Thanks, I'll keep the second jar on stand by incase I have any disasters with the first and then once fermentation is underway I'll chuck it and harvest again from the next batch.