Yeast harvest re-pitching

[Doctormcbrewdle]

I've never actually reused yeast yet and am looking to try next brew right after this current brew is done. Though I'm looking to gain sone insight into how much should be pitched..

I'm reading as little as 1/4 cup for 23l but Wyeast who are of course a very well trusted source recommend 1l for ale's under 1.064 and double that for lagers under 1.064. Is this about right?

Second question is, if harvesting for later and refrigerating, some say a loose fitting lid (guessing for expansion?) but I'd imagine tight fit to keep nasties out?

Third question, will repitched yeast show signs of active fermentation right away or does yeast react like dried yeast and reproduce before beginning?

Thanks!

 

[wide eyed and legless]

You may find this helpful.
https://aussiehomebrewer.com/threads/ahb-articles-yeast-harvesting-amp-freezing.46428/

 

[menoetes]

This guy does a good video for harvesting and washing that I have followed in the past just re-using old olive and vegemite jars and the yeast worked great with a 1lt starter to wake the yeast back up.

A quick and lazy method (that some might not agree with) is to just save a portion of your yeast cake. Just sanitize a large measuring cup and a nice big glass jar or two (400ml or bigger was always my preference) then carefully just scoop as much of your yeast cake into the jars until they are full, then seal them up, wash the outsides in sanitizer and put them in your fridge to store until needed. I only used this method if I was planning to reuse the yeast within the month as its not the ideal way to store yeast.

Again, the first method is the better practice and will give you cleaner yeast in better health. The second makes up for quality with volume but also includes dead yeast, hops and other matter that made up your original yeast cake - but works fine IMO if you are brewing the same or similar style again.

In both cases, using 1- 2 liters of starter really helps get the yeast back up and going after being dormant in the fridge. Bigger starters for bigger beers of course but there are calculators online for that info.

 

[Doctormcbrewdle]

Well I bottled a pale today and decided to remove half the slurry and pitch on top. Just a few hours on and I'm at full Krausen..! Making sure I keep it a bit below what I normally would due to the extra heat but this is fantastic. M44 yeast usually takes 2 days to start so really nice to have this happen and cheaper

 

[Danscraftbeer]

Lots of reading. What I just did on the weekend brew is about as good as you can get and that's fresh yeast cake for the next brew. Boiled (in phosphoric sanitizer) a mason jar (canning jar) actually I pressure cooked the jar and 2 part lid because Its just as easy but better. It had cooled down by time of scooping some fresh yeast cake (soup ladle spoon also boiled with the jar) and into the sterile jar. Cap it. I had no need to chill it just kept it in the temp control fridge for a few hours. Cleaned and sanitized kegmenter close to end of chilling new wort then dropped in the yeast dollop then racked in the new wort etc. O2+shake well and its on the go in 6 hours.
http://www.mrmalty.com/calc/calc.html calculated 100ml thick yeast for 40lt at 1.048. It was closer to ~ 160ml what gooped out of the jar into the kegmenter.
That's the simplest method I do. The other is zero exposure method with pressure fermenting. After you have transferred out all the beer is to inject boiled/sanitized water (same temp as the yeast cake) into the unopened kegmenter . Shake and roll it to mix and wash the yeast. Let it sit upright and then pressure transfer the slurry into PET bottles to keep in fridge for up to 6 weeks at most.

 

[Gloveski]

My method so far has worked well is after first batch (pressure fermented). I will remove a decent scoop of yeast and then new wort straight on top without cleaning fermenter. After this batch has fermented out I will scoop out some yeast with a little bit of liquid from the brew and then fridge it if not ready for a new brew. Thoroughly clean fermenter after second brew I keep in the refrigerator no more than 3 weeks so far before being used. As I brew two brews at once I have a Us05 and Wyeast 1968 on the go atm
I have been slightly over pitching to compensate for trub and dead yeast
I usually have pretty clean yeast after a brew has fermented out as I strain my wort before entering fermenter and don’t dry hop in fermenter .
I think anymore than 3 weeks and I will look at a starter , but in the next few days I will brew with 5th gen yeast for both strains . To be honest I think the beers are getting better with each generation of yeast . I’m not sure how many more generations I will use , maybe 2 at this stage before I will use new yeast .

 

[Gloveski]

Took a bit of finding again but this is what I based my idea of roughly 3 weeks without doing a starter from , but if in doubt a starter would definitely be the go , but they are hardy little fellas https://www.beeradvocate.com/community/threads/yeast-in-storage-viability-and-vitality.149989/