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3 week old harvested yeast....starter?

I harvested my yeast from my Ruination clone 3 weeks ago (OG 1.075) and plan on brewing a porter this weekend (target OG 1.060). Think I need a starter or would I be OK just pitching half the harvested yeast?

EDIT: removed some redundant phrasing

It’s not generally recommended to use yeast from a higher gravity beer like the Ruination in a lower gravity beer. The yeast are stressed. The general rule I follow, is to repitch into either: like wort (color, hoppiness, gravity) or pitch up (darker, higher gravity, hoppier).

Three week old yeast, however, is probably fine without a starter. I usually direct pitch harvested yeast that is up to a month old usually. Sometimes if it’s older than 3 or so weeks, I’ll make a 1L starter just to wake them up a bit and get them ready to eat.

I wasn’t sure if that was a myth or not. So the giant jar of yeast I have in the fridge is pretty much worthless? (Unless I brew a RIS)

Yeah I wouldn’t recommend using yeast from a stronger batch of beer on a weaker one, if reusing yeast, always step up, not down. For example, I may brew a 1.048 pale ale and reuse the yeast on a stronger pale ale, IPA, or double IPA.

Wake them up feed them some wort and send them in. Just kidding, but that’s what I would do. I don’t have enough experience with yeast yet but I’m trying to learn. What strain you talking about?

I don’t think it is a myth per say, but I do think a lot of brewers make too much of it. There are lots of things that put stress on yeast: under/over pitching, wrong fermentation fermentation, underoxygenation, exposure to high alcohol levels, aging, the list goes on. Pretty much any of those factors can be overcome by babying the yeast back to health with a nice starter.

The other risk with stressed yeast is the increased chance of mutation. This may be a myth - I’ve never heard of someone who has reported this actually happening due to reusing yeast from a high gravity batch - but even if real the odds of it happening in a given case are tiny.

I’d go ahead and use the yeast as-is if it looks and smells fine. If in doubt, make a starter.

What do you think, half a cup or so of yeast slurry in a 1.5L starter should do the trick?

I saved some unwashed WY3711 cake in three jars. Three days before I brewed I let one jar warm to room temp, I also let one liter of saved wort ( 3rd running) warm up. I then decanted the liquid that was on top of the cake and poured 200ml or 1cup of the center part of the slurry into the wort. Shook it good and put on a cap and airlock. Fermented out before I was ready to brew so I chilled it again. On brew day let it warm and again saved 3rd run wort from the batch and chilled about 1/2 liter during my boil, I then decanted and pitched the whole slurry into it . By time I was done chilling the yeast was working. Pitched it all and it took off like a banshee and hasn’t stopped yet, day four.

What do you think, half a cup or so of yeast slurry in a 1.5L starter should do the trick?[/quote]
Plug the numbers into the calculator at Mrmalty.com, making sure to fill in the fields for time since harvesting and estimated amount of trub mixed in, then round up a bit if you want. Slightly overpitching will not cause a problem in most beers.

Not to confuse the issue but I tried using the calculator but how accurate is it when it comes to slurry. I imagine all slurry is not created equall how many yeast cells are in there. I think the calculator would have to er on the side of overpitch. I read rule of thumb 1/3 to 1/2. I would do 1/3 with starter or 1/2 without. But like I said I’m not that experienced yet. Open for debate though. Just trying to learn

I may just pitch fresh yeast. I only get to brew every couple months or so and I really hate waiting 1.5-2 months to drink a below average product.

Not sure it would be below average I’ve used fresh and repitched to the same recipe and both came out awesome. I can’t tell the difference. Why don’t you split the batch.

But then again if you don’t brew very frequently why bother. Yeast is cheap.

This is kinda what I was thinking. If I was turning over batches right after racking off the yeast then it would be a lot easier. Now I really only know about a week beforehand if I’ll have time to brew so storing a whole bunch of yeast in the fridge (and taking up space to the dismay of my wife) only to find out I won’t be brewing for another month or so, kinda makes it a crap shoot.

I would be interested in hearing from people who successfully use yeast 3 or more months old without an issue, how much slurry they use in their starter and how they calculate pitch count without using a microscope.

If my yeast was harvested within a month, I consider it fresh enough to not worry about, and I’ve never had a problem with it. More than two months old, I always use a starter. Between those two, it is kind of a judgment call.

I’ve stored yeast for a year in the fridge and then babied it back to pitching condition (stepped up starter). Not sure I’d recommend that if you can just go out and buy a new smack pack. Up to four or even six months though I’ll use the stored yeast. On average, that makes it fresher than the smack packs I can get. YMMV.

[quote=“rebuiltcellars”]If my yeast was harvested within a month, I consider it fresh enough to not worry about, and I’ve never had a problem with it. More than two months old, I always use a starter. Between those two, it is kind of a judgment call.
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That’s pretty much what I do, too. I’m brewing next week with slurry that will just about a month old, and I’m not making a starter.

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