2 month old yeast - starter?

[rhys333]

Hey guys,
I have 2 month old harvested yeast i want to use this weekend. It was top-cropped and close to 100% pure viable yeast at collection time. I also have a lot of it, maybe 200ml, so in theory enough for a direct pitch. Question is, should i bother making a starter because of age? If so, should i use all of it in a tiny starter just to freshen it up, or a small amount in a large starter to build up new cells? Thanks in advance.

Mr Malty tells me what I have is defaulting to 10% viable, but i'm tempted just to direct pitch...

 

[Sudz_Makenzie]

I run into that problem with some of my strains because I have a pretty good variety. I usually use the older stuff to make a fresh starter just for safety's sake and not risk screwing up a 5 gal batch.

 

[WoodlandBrew]

Mr Malty tells me what I have is defaulting to 10% viable, but i'm tempted just to direct pitch...

Mr. Malty has been way off when I have compared their viability estimates to actual viability counts on a hemocytometer. Also, fermentation performance has indicated that the viability estimate from Mr. Malty is much lower than reality.

After two months in the fridge I would be surprised if your viability was less than 70%.

Here is more information on viability in the fridge:
http://www.woodlandbrew.com/2012/12/refrigeration-effects-on-yeast-viability.html

Viability compared to Mr. Malty:
http://www.woodlandbrew.com/2012/11/counting-cells.html

 

[rhys333]

Thanks for the input guys. Interesting read WoodlandBrew. I agree based on my own observations, though I have never direct pitching after 4 weeks so this will be an interesting experiment for me. I'm going to assume 75% viability and see what happens. Worst case scenario, I have a second jar I can use if I don't see activity within a reasonable timeframe.

 

[AerationStation]

It does also depend on the yeast strain. I've noticed my weizen yeast are crapped out after a month

 

[beowulf]

I must have superman yeast or something because I direct pitch all the way up to 6 months. It does take a bit longer to start fermenting when it gets over a few weeks but it has always worked (yes, ALWAYS...for probably 50 batches or so) and my attenuation is normally exceptional. I've had the same experience for a number of strains from U.S. to British to Belgian. I don't have any experience with weizen yeast.

Once it's over 6 months or so, I might make a starter. I'm not certain it's necessary, but it does help wake it up a bit. Recently I took a jar of yeast that was about 13 months old out of the fridge, made a small starter then pitched into a 1.092 wort....in 2 weeks it's down to 1.013. Goes to show you how tenacious yeast can be Just my experience...your mileage may vary.

 

[flars]

I must have superman yeast or something because I direct pitch all the way up to 6 months. It does take a bit longer to start fermenting when it gets over a few weeks but it has always worked (yes, ALWAYS...for probably 50 batches or so) and my attenuation is normally exceptional. I've had the same experience for a number of strains from U.S. to British to Belgian. I don't have any experience with weizen yeast.

Once it's over 6 months or so, I might make a starter. I'm not certain it's necessary, but it does help wake it up a bit. Recently I took a jar of yeast that was about 13 months old out of the fridge, made a small starter then pitched into a 1.092 wort....in 2 weeks it's down to 1.013. Goes to show you how tenacious yeast can be Just my experience...your mileage may vary.

@WoodlandBrew I have just had similar results with old harvested yeast. Current fermentation is proceeding nicely. Direct pitched 320 ml of yeast, hop debris strained during pour into fermentor, harvested July 13, 2014. New wort was five gallons, 1.052.
Pitched yeast at wort temperature of 56°, Day 0. 21 hours later wort reached 64°. 21.5 hours later 1/4 inch krausen formed, 66.2°. It is now Day 6, very normal fermentation.

How much yest did you pitch into the 1.092 wort? Was this yeast free of trub?

 

[beowulf]

flars - I don't typically "wash" my yeast, per se. Once I empty the fermenter, I just sanitize a scoop and scoop it into a sanitized jar (usually 8oz jelly jar). If I have more than 8 oz then I use multiple jars or use a bigger jar. I filter the trub pretty good coming out of the kettle so the yeast I harvest is usually quite clean. I don't notice the defined layers that you might see if you have a lot of trub in the fermenter. To illustrate, I have attached an image of some yeast taken from a brown ale.


For this batch, I took a 16oz jar which was about 2/3 full so maybe 10-12 oz or so and split it for 2 different batches. We'll say 6oz per batch. Then I made a small starter (1 liter) to wake it up and pitched the starter. I don't have a precise amount to give you, but I'm guessing it may have been 6-7oz of yeast. By volume the conversion for this is in the neighborhood of 180-200ml of yeast. I just checked and this volume happens to be what MrMalty recommends for ~80% viability yeast for a 5.25gal batch at 1.092. I was really just trying to get down to 1.020 but alas WY1728 had other plans.

Edit: why does HBT keep turning my images 90 degrees?

 

[flars]

I swirl up the beer and yeast cake in the fermentor and pour into a quart canning jar that is roughly marked in ounces on one side and milliliters on the other. 370 ml, after a week of settling, is my typical harvest from a 5 gallon brew.

 

[rhys333]

Well I thought I'd report back with my observations on that two month old yeast. It took 36 hours to grow a half-krausen and there's no sea-monkey swirling action going on as of this time. With 1469 I usually get activity in 8-12 hours, and a full krausen at 24 hours that gets skimmed and discarded. It's definately acting beat up and abused... wondering if a small starter would've helped.

 

[brewprint]

Edit: why does HBT keep turning my images 90 degrees?

I've noticed this as well. If I just hold my phone straight up and not do a 'wide' screen shot they come out correct. Must be the format of the forum.