Harvesting yeast directly from Fermentasaurus

[BritishBelgianTwst]

Hi all,

I got a Fermentasaurus last Christmas and used it for the first time the other week.
It's great fun being able to see the fermentation in progress as opposed to the traditional white plastic buckets that I've used before.
Anyway, as I'm getting round to sorting out a kegerator and as I'll have my own cold place to keep hops and yeast I'm planning to start harvesting.
So my question was, can I just harvest directly from the Fermentasaurus after dumping the first load of sediment/trub?
My idea would be to dump once into the bottle at the base of the conical fermenter, throw the content, reattach the bottle and wait for the yeast to settle to the bottom and then re-dump that. Cap the bottle and keep in the fridge until the next batch.

Is that a viable option or should I really wash it?

Oh and anyone know where I can get cheap soda stream bottles? That is the size of bottle that fits the fermentasaurus so I'd like to get a bigger one that could handle the amount of trub that I ended up with first time out.

Cheers!

[Kev888]

Thats more or less right (for conicals in general anyway). Though I wouldn't try to rinse it; by dumping/discarding rubbish beforehand you should be able to collect clean slurry to begin with. About the only reason to rinse the collected sediment is if the gunk makes it hard to judge the quantity of yeast you have, and there shouldn't be too much unwanted stuff with a conical. Plus, the yeast keep better under a bit of the beer they have produced, than they do under water.

'When' to harvest the yeast is quite important. Too early and you can select cells that die or drop out prematurely, too late and you may get cells that flocculate poorly. There are different opinions on this, and it depends on the yeast and the actual fermentation progress (not just time), but generally I go for the yeast that fall out towards and somewhat after FG being reached.

Depending on how much yeast slurry you collect and how long it is kept for, you may or may not need to make a starter. Though (especially as time goes on) you may wish to in any case, just to check that things are still as expected.

[BritishBelgianTwst]

Thanks Kev, glad to hear I was along the right lines.
To be honest I never make starters, generally I just dump a sachet of yeast in the wort.
I’m also lazy and don’t often take the SG of my beers

[Kev888]

Well its rare to make starters with dried yeast, since they are generally bought partly for convenience and they are packaged ready for the main batch (some characteristcs would be wasted on a starter). So generally people just pitch enough packs for their brew; ideally re-hydrating first, but even then many people don't bother and just pitch it dry.

If you collect enough slurry and use it fairly soon (a couple of weeks or so) you likely won't need to make a starter there either. However it ages very quickly, compared to dried yeast so before long you may not have enough viable cells left for a good fermentation without first building their numbers up in a starter. If there is going to be significant time between collecting and using the slurry, or if you don't manage to collect much to begin with, it would probably be worth learning to at least roughly estimate the quantity of viable cells you have, so that you can be sure of having sufficient.