yeast harvesting and yeast starter

[Wonderwoman]

Can you harvest yeast that once was dried yeast from a sachet? Would this make sense or do you only do it with fresh yeast?

Should I do anything with the yeast cake on top or just wait until I bottle then harvest and wash the yeast as instructed.

The other thing I was wondering about making a yeast starter from your harvested yeast... Would it make any sense in theory to keep some of the OG wort to make a starter or would that have gone off by the time you want to do your next brew? I guess I'm just looking for an easier way that using malt extract etc

How do you know how much of your own yeast to add to a new brew?

 

[clibit]

!. yes you can harvest yeast that was dried.

2. You can crop yeast off the yeast cake, but do it when it's at peak fermentation time, usually 2-3 days after pitching. Some yeasts are good for this, others not. If there's lots of yeast on top, it's a good one!

3. You can freeze wort and use it in a starter at a later date.

4. I use a yeast calculator on the Mr malty website, this was created by the guy who write the Yeast book. Click the 'Re-pitching from Slurry' tab.

http://www.mrmalty.com/calc/calc.html

 

[Covrich]

!. yes you can harvest yeast that was dried.

2. You can crop yeast off the yeast cake, but do it when it's at peak fermentation time, usually 2-3 days after pitching. Some yeasts are good for this, others not. If there's lots of yeast on top, it's a good one!

3. You can freeze wort and use it in a starter at a later date.

4. I use a yeast calculator on the Mr malty website, this was created by the guy who write the Yeast book. Click the 'Re-pitching from Slurry' tab.

http://www.mrmalty.com/calc/calc.html

Interesting to know that.. I was going to try harvesting on my liquid and for wahever reason I was going to scoop up the trub after I bottled my batch.. You think its better to skim the krausen and stick that in a jar?

 

[clibit]

If the yeast is s type that throws up lots of yeast on the surface you get better quality yeast than you do from the slurry at the bottom. You should crop it at 'high krausen' when it is at the peak activity point. But I use the yeast sediment from the bottom successfully too. Google 'top cropping yeast'. Here's a good article...

http://www.love2brew.com/Articles.asp?ID=445

 

[Wonderwoman]

Great stuff, thanks! I brewed it on Saturday night and had a sneak peak yesterday (had to show my Dad ;-)) and it had a really thick dark bubbling slush on top. The temp is quite high (I'm lowering in it as it was 22 degrees so now it's 21, the highest limit as suggested by Danstar) and I read that the Nottingham Ale yeast ist super quick to ferment and finish the fermentation process. So I better be quick to take some. How much can I take/should I leave behind? does the wort need any of the top krausen?

 

[clibit]

You can take as much as you like, there's plenty beneath the surface.

 

[Wonderwoman]

This is crazy, it's already gone now, sunk to the bottom. So for the danstar nottingham I guess it's best to harvest it 24hrs after pitching (especially when pitched at high temp). So I guess I've got to go the bottom cropping route this time. I will try it next time though, I reckon. And also keep freeze some wort for that matter - just out of interest... if I as to harvest this ale yeast this time and was brewing let's say a Wheat Beer next time, I assume it doesn't make any difference to the yeast, if I use wheat beer wort as a starter, does it? I would then pour as much away as possible of the wort before pitching the yeast.

NB: When the yeast sinks to the bottom like it has now, what does that mean for the fermentation process? I don't want to take a reading yet and disturb it unnecessarily, but does that mean it is close to finishing fermenting? As far as I've understood, you would usually wait 7-10 days for this process before bottling it, but should/could I bottle this beer already even when the fermentation may have finished after 3-4 days? It is a high alc beer, if that makes a difference. the outcome ABV should be about 6% (but I'll see when it's done I guess - probably end up leaving it in the FV longer anyway as I don't know the suggested FG)

 

[clibit]

No problem, Nottingham is not a good yeast for top cropping. You would be unlikely to get much anyway. And I don't think people tend to harvest from dried yeasts very much, as they are cheap to pitch a fresh packet. It's perfectly ok to do so though, and i do it sometimes.

The best top cropping ale yeasts seem to be some of the liquid strains, like Wyeast 1318 London III, and 1469 West Yorkshire Ale.

When yeast sinks to the bottom it does it gradually, as it finishes its work. The bulk of the fermentation job is over in 3 days usually, but there will still be some yeast in suspension finishing off the job. I always leave the beer in the FV for at least 2 weeks, cos stuff is still happening, even though the sugars that the yeast can consume have all been consumed.

I wouldn't use Nottingham for a wheat beer. But you can use wheat beer wort to make a starter, yes. You'll pour the beer off and just pitch the yeast, like you say.

PS When you top crop, if there's green/brown scum from hops/grain on top, take that off and discard it when the krausen first forms, then wait for the krausen to re-build and crop that, after 2 - 3 days.

 

[Wonderwoman]

Okay, will do! I will try and harvest some from this batch in the end, I think. It was a good yeast so far and although dried yeast is quite cheap, if you can have it for free and don't have to order it, why not :)
I've got wheat beer yeast for wheat beer, just as I've just done a lager and want to perfect my wheat beer recipe, I think that's what I may be brewing next. But first things first

I will give it some time in the FV. I guess the question is though, at what point do I not have to worry about sticking to the recommended yeast temperature anymore? I've lowered it now to 19 degrees, as it was getting a bit too warm really - probably okay for that sort of beer and I've heard good things about the Notti. But as I've got the FV indoors, how long will I need to keep it wrapped in a wet towel (2 weeks would really be a bit of a nuisance) - or at what temperatures should I store the FV for the next 1-2 weeks once the actual fermentation has finished?

If I was to do a gravity check tomorrow or so, would I already have the fg, assuming that the fermentation has finished?

 

[clibit]

You can let the temperature rise once the main fermentation is over, when the gravity will be at or close to FG.