Yeast Harvesting

[TRXnMe]

Right, when I made my last small batch AG brew I saved a couple of litres of wort and put it in a nice clean demi john, a couple of nights later I allowed myself two bottles of Fullers Bengal Lancer and tipped the last 1/2" of each bottle into the wort.

Well, nowt happened for a couple of weeks, then, boom, over the last 4 days it's formed a really nice kreuzen and is bubbling away happily.

Now, the question, what is the best way to harvest some of this yeast for use in a pale ale I'm planning for next month? I can leave this demi john in a dark(ish) place until then and syphon out some of the trub if that's a good idea?

I also have a couple of old honey jars that I could put some of the wort into, with some brewing sugar, and culture more that way.

Lots of ideas, most of them picked up from the net, but what's the best, safest, way of getting this yeast ready to work on my pale ale?

TBH I didn't expect the yeast to take, so I'm chuffed it has, but surprised and so, not really ready for it

 

[Muddydisco]

For me I would chuck it in a pet bottle once Fermentation is over and bung in the fridge until day before you need it.

 

[graysalchemy]

If you are going to use it soon I would do as Nick says. I wouldn't put any sugar in there brewing sugar or ordinary you want the yeast to go to sleep and in anycase using sugar may change the yeasts metabolic pathways.

I did the same however it didn't keep long as I didn't store it properly. I would take it of the beer and wash in sterile water then put it in a sterile container until brew day, should last a month. when you are ready make up a starter 3 -4 days before to check the viability of the yeast then if it is ok and there are no off flavours in the fermented wort use it. :thumb:

 

[TRXnMe]

Sorry to sound stupid here, but...

What do I put in the PET bottle?

The 'beer'
The stuff out the bottom of the demi john
The stuff off the top of the beer?

I've read a fair bit about this, and it seems like different folk are advocating all three, some folk seem to be saying that the stuff off the bottom is good, others that the good stuff is what's floating on top, I know there is live yeast in the beer... so, I'm confused

This is probably dead simple, but I've managed to massively complicate it in my head watching youtube videos fo different methods and reading articles on the internet.

The only bit I really understood was that you had to use good wort to cultivate the stuff from the bottle, or the yeast might mutate into something odd.

 

[graysalchemy]

The stuff at the bottom :thumb: . You can top crop the clean krausan off a fermenting batch of beer but I wouldn't off a starter as it would be hard to get.

:thumb:

 

[TRXnMe]

Thank you Mr Alchemy Sir :)

So, all the options I've read would work.

I take it 'cropping' the krausen off the top of a batch is only really achievable from a bucket type fermenter, rather than a demi john or screw top fermenter? With this would you just sterilise a jug and scoop the krausen off, then put it into a 'starter' of wort?

Sorry to keep asking these questions, but I'm starting to understand just what a part yeast plays in the taste of cider, wine and beer and havinng found out just how easy it is to culture yeast from beer bottles I'm now leaping ahead to never havinng too pay £2 for a sachet of dried yeast again*....


*quite a while to go before I get there, but a nice concept for a Yorkshireman :)

 

[graysalchemy]

I scooped my last one off with a big sterilised spoon. No need to make a starter just putin a tub in the fridge to settle. I got over 3l from my last one. :whistle:

 

[The Goatreich]

I got confused initially with what portion to keep, but it's basically in two stages if you're using a yeast cake (I know you're not, but that may be where the confusion with the videos is coming from).

1 - pour the yeast cake from the bottom of the FV into a sterilised PET bottle, I use a 2l pop bottle, then leave for about 30 minutes and you'll see it separate into 3 or 4 layers. The bottom two layers are hop and grain crud which you want to discard by slowly decanting the top two layers (beer and yeast) into another sterilised vessel. You can then wash this yeast with boiled cooled water if you so desire.

2 - The beer and yeast solution can now be put into the fridge, which will encourage the yeast to compact down to the bottom, meaning that when ready for you to make a starter you can decant off the top layer and add the yeast at the bottom to the fresh wort.

Does that make sense?

 

[TRXnMe]

Aye, that makes sense, it's what I thought was going on from the youtube stuff, I was confused by the alternate of taking the krausen, and references to dead yeast from people talking about both methods.

GA's simple description of taking the krausen makes sense and seems to be the easiest way to do it, I'll probably try it, I've got a stainless ladle that will fit into my screw top FVs nicely.

By the time I'd done reading articles and watching youtube I was convinced that either the floating stuff, or the sunk stuff had to be dead, in which case the methods on offer made no sense.

I knew I'd get some sense on here, it was just a case of getting around to admitting I didn't get it and asking :)

 

[graysalchemy]

If you are using the yeast cake then I would advise to take it off the beer and replace with sterilised water, as the beer can go off.

As with top cropping you need to make sure the Krausan (or barm as it should be called in Lancashire) is clean. You can continue to crop it until it has gone. I managed to top crop and also take the yeast cake.

Again once it has settled take it off the beer/wort and replace with sterilised water.

:thumb:

 

[TRXnMe]

OK.

I see lots of referencecs to small quantities of liquid for the starter, is there any particular reason for this?

My Bengal Lancer dregs went into 2 litres of wort, will that have knackered it? It smells good now it's underway, I thought the only problem with a larger quantiyt was that it would take quite a while for the culture to get large enough to make any noticeable difference?

 

[graysalchemy]

I think a larger volume of wort runs the risk of getting infected as the yeast is not able to establish a large enough colony quickly enough. Hence also why you need a certain amount of yeast to pitch into a full batch of beer and the need for a starter.

:thumb:

 

[DirtyCaner]

Is there any reason you couldnt grow a big starter, use half for a brew then grow the remainder up again and keep going like this? I know you are only supposed to use the yeast a few times but does that include growing the starter.

I quite like the idea of having a mother culture that you just keep usinga bit of.

 

[graysalchemy]

You could do I supose, but the trick would be to keep it alive and healthy. I would personally make a large starter and then keep back 10 x 50ml portions and freeze them. Each of these would be viable for 7 generations so if you split it into 10 you would get 70 brews out of one batch. However the limiting factor would be how long it survived in the freezer you would probably get a few years out of it. :thumb:

 

[Baldbrewer]

I've got some 50ml syringes, could I fill these with yeast/water solution and freeze?

 

[graysalchemy]

you are better off with centrifuge tubes like these

But I suppose you could use syringes. :wha: :wha:

 

[TRXnMe]

7 Generations?

Where does that come from? What happensif you use too many, and ($64k question) ow did the brweries develop their special yeast without going over the 7 generations?

GA, do you have any suggestions on something simple I could read to get me started with a grounding in yeast?

Your info is great, but I'm just asking more and more questions, if I've got a decent resource to read up on I will at least ask more intellegent questions.

 

[graysalchemy]

7 generations for home use as genetic drift becomes a problem. Breweries do all sorts of things including acid washing the yeast and only using top cropped yeast etc.

'Yeast' by Chris White here is an excellent read

:thumb:

 

[Springer]

Thanks for that link G, I will get a copy for winter reading, to keep my knowledge up with the pack :thumb:
S

 

[Good Ed]

You won't be disappointed with the book S; there is a section on making starters, dealing with volumes and yield factors to get the quantity of yeast that you need, sounds complicated, but isn't really, but it's a difficult to write it out here to give people advice when people ask how big a starter to make.