Don't want to over-pitch my harvested yeast

[rhys333]

Hey guys,

The online calculators aren't much help when it comes to making starters for, and pitching, top-cropped yeast. Last time I went by the numbers I ended up with a massive over-pitch.

I have about 200ml of 4-5 week old 1469 WY West Yorkshire, which I estimate to be at least 75% viable (not < 10% as per calculator guestimates). I could direct pitch, but that's probably not smart. Thinking a very small 1L starter would be best, just to confirm viability and wake the yeast up. Even then, I might only pitch about 2/3 of the starter into my batch.

What do you guys think? I realize its all trial and error at this point, but anyone that's had the same experience and learned through doing this a few times, I'd really appreciate your feedback. Cheers.

 

[philosofool]

https://www.wyeastlab.com/com-yeast-harvest.cfm

Summary: according to Wyeast, 1 mL of pure slurry is about 2.4 billion cells, but you should figure out what portion of your impure slurry is actually yeast cells. This can be done in a smal vial with a small sample of the slurry and water: shake heck out of a slurry watter mixture and the vast majority of dark sediment will be non-yeast, the creamy white top layer will be yeast. The relative sizes tells you the cells as a percentage of slurry volume.

Example: if you get 75% white layer in your sample, then the slurry is .75*2.4 bil cells per mL.

 

[F_R_O_G]

my experience is, why have the chance of wasting all that time and money making beer when you can spend 5$ for a yeast packet that's a sure thing. make a starter if you don't want to buy 2 packets.

 

[riderkb]

Hey guys,

The online calculators aren't much help when it comes to making starters for, and pitching, top-cropped yeast. Last time I went by the numbers I ended up with a massive over-pitch.

What were the effects of over pitching that you are hoping to avoid?

 

[rhys333]

What were the effects of over pitching that you are hoping to avoid?

Loss of desired yeast character and possible off-flavors from over-pitching.

 

[rhys333]

https://www.wyeastlab.com/com-yeast-harvest.cfm

Summary: according to Wyeast, 1 mL of pure slurry is about 2.4 billion cells, but you should figure out what portion of your impure slurry is actually yeast cells. This can be done in a smal vial with a small sample of the slurry and water: shake heck out of a slurry watter mixture and the vast majority of dark sediment will be non-yeast, the creamy white top layer will be yeast. The relative sizes tells you the cells as a percentage of slurry volume.

Example: if you get 75% white layer in your sample, then the slurry is .75*2.4 bil cells per mL.

Thanks for the link. I viewed this previously and its an excellent resource. It mentions top-cropping, but the content seems more focused on harvesting post-fermentation. From what I can tell, the top-cropped stuff I have is close to being pure yeast with almost zero trub inclusion. I recall my last batch with TC yeast showed activity within 1 hour (both starter and main batch), leading me to believe I pitched way more than needed.

 

[F_R_O_G]

I don't claim to have a complete grasp of yeast harvesting but from what i have read from "Yeast" and other sources and my own experiences i don't think i will ever harvest yeast.

i know that harvesting yeast from your last batch of beer is a popular idea and you can make good beer with it. but you can't make excellent beer by reusing yeast except under very controlled conditions that are outside of possibilitys for most home brewers. inputting exact o2 concentrations, harvesting at full karasen, and proving all the right nutrition are some of the more difficult items to ensure proper yeast harvesting. After you have the yeast you MUST have a way to accurately count the yeast. I've used this analogy before. counting yeast cells without a microscope is like counting m&m is a large jar. you can be so far off that your number is useless. here is an example of someone counting yeast by volume then counting with a microscope. http://www.woodlandbrew.com/2012/11/counting-cells.html

using "calculators" he calculated 400 billion cells per liter. but when he counted under a microscope he found he had 2000 billion cells per liter. these calculators are no better than a wildassguess.

there's also the issue of vitality and viability things you will never know without a microscope. why is this important? under 90% viability can cause autolysis and a lot of low vitality cells may not be able to finish fermentation.

if you want to make good beer then make sure you pitch a little more than you think it needs and i'm sure you will not have any issues. but if you want "perfect" beer, or as close as you can get, you can never reuse yeast.

 

[orangehero]

You should probably re-read Yeast, because the authors point out that yeast don't begin to perform optimally until several repitches. Nowhere do they advise against the practice.

Although the calculators may be inaccurate, you still need to measure, observe the effects, and make adjustments for your own brewing system just like they do in any brewery to nail down your technique and get the results you desire. Some people like to measure to the third decimal point, but once you get experienced and comfortable with brewing you realize there is a lot of room for the processes.

I think you're setting a misguided and impossible standard for "excellent" beer. Yes, you're not going to get the repeatability of budweiser, but that doesn't mean your beer is just "good". Most craft breweries are not at the level either, including those producing some of the most sought-after beers. What leads to "perfect" beer is practice and understanding your equipment.

 

[riderkb]

I think you're setting a misguided and impossible standard for "excellent" beer. Yes, you're not going to get the repeatability of budweiser, but that doesn't mean your beer is just "good". Most craft breweries are not at the level either, including those producing some of the most sought-after beers. What leads to "perfect" beer is practice.

It does seem like there are a lot of brewers, I assume new brewers, who think that a perfect beer is one that was mashed at exactly the same temperature as the recipe said, hit the OG from the style guide, and was fermented with the recommended amount of yeast from an online calculator. They must think it seems like science that way, but it is actually just an over-application of theory. It's better to do a lot of experiments and take good notes. Empirical data will take you a lot farther than theory in this game.

 

[rhys333]

i know that harvesting yeast from your last batch of beer is a popular idea and you can make good beer with it. but you can't make excellent beer by reusing yeast except under very controlled conditions that are outside of possibilitys for most home brewers.

I disagree. Beer production is a centuries old process rooted in craft, not science. Keep in mind traditional harvesting/selection over many generations is why we have specialized yeast strains today. As for quality, my own harvested yeast has performed better than the original store bought packs. It's also a fun part of the hobby for me, and doesn't hurt that by doing it I get to save $10 each time I brew.

 

[rhys333]

Just to circle back on the OP, I'd apprecaite hearing back from anyone that cycles TC yeast regularly and has an approximate pitch rate figured out based on repeat experience. Just not sure about pitching 100% of 200ml packed yeast + starter.

 

[F_R_O_G]

i knew i would get a lot of responses for that post

I might try to submit a article about this but for now i'll respond this this.

It's better to do a lot of experiments and take good notes. Empirical data will take you a lot farther than theory in this game.

if our goal is the best beer possible then you need both theory and experience. the wrong theory will prevent you from making good beer. you must have a sold foundation. once you know what's suppose to happen you can build on that. also it is much harder to repeat exceptional beer without knowing all the little details. in a production brewery setting they know how much yeast they are pitching...

I talked to the head brewer at diamond-knot here in north Seattle when i first started. his recommendation was to read the books first then use online as a supplement.

 

[Smellyglove]

I once read an interview with Jamil Z where he said something like that if you're on your third generation of yeast, then you're talking about competition worthy yeast. This is from the back of my head so I unfortunately don't have the source.

For every time you repitch, until it starts to mutate and give you undesired characteristics, repitched yeast gets more combat-ready for every generation. But if you underpitch you'll be harvesting tired cells, and tired daughter-cells.If you overpitch the cells will not grow enough daughtercells since they don't need any more hands to to the job and you'll harvest mostly old tired cells.

 

[JonM]

Maybe I missed it, but why are you assuming it's 75% viable rather than the 10% predicted by the calculator?

 

[ericbw]

i knew i would get a lot of responses for that post



I might try to submit a article about this but for now i'll respond this this.







if our goal is the best beer possible then you need both theory and experience. the wrong theory will prevent you from making good beer. you must have a sold foundation. once you know what's suppose to happen you can build on that. also it is much harder to repeat exceptional beer without knowing all the little details. in a production brewery setting they know how much yeast they are pitching...



I talked to the head brewer at diamond-knot here in north Seattle when i first started. his recommendation was to read the books first then use online as a supplement.

You have to have a stronger foundation for your position than the fact that a brewer told you that books are better resources than "online."

 

[ericbw]

<<using "calculators" he calculated 400 billion cells per liter. but when he counted under a microscope he found he had 2000 billion cells per liter. these calculators are no better than a wildassguess. >>

I've always thought the calculators underestimate viability, etc. after all, you can culture up from bottle dregs that are who knows how old and under unknown conditions. Yeast seems to be pretty tough.

 

[rhys333]

Maybe I missed it, but why are you assuming it's 75% viable rather than the 10% predicted by the calculator?

Because I get activity within an hour, both for starter and main batch. Vigorous at that. If I trust the calculators I'm underpitching, which can't be accurate. Fresh smack-packs I use (with appropriately sized starters) take longer to kick off. Best I can figure is that calculators are geared towards stressed out post ferment yeast rather than healthy top-cropper stuff.

 

[ChelisHubby]

What makes you think that the yeast from the blow off tube is better than from the bottom of the bottler bucket or are you opening the bucket and removing Krausen? Honest question not looking for a fight.

 

[F_R_O_G]

What makes you think that the yeast from the blow off tube is better than from the bottom of the bottler bucket or are you opening the bucket and removing Krausen? Honest question not looking for a fight.

the longer the yeast sits with the alcohol the lower the viability it will have, I don't think there's any argument on that. the issues comes when harvesting. you have to be very careful not to contaminate the beer when harvesting from the krausen. for some it's worth the risk for others it's not.

 

[rhys333]

What makes you think that the yeast from the blow off tube is better than from the bottom of the bottler bucket or are you opening the bucket and removing Krausen? Honest question not looking for a fight.

All good my friend. I 'open' ferment with a loose fitting lid, scooping yeast off the top as you descibe. I do an initial dirt skim at 24 hours. This gets rid of hops, trub, and early floc yeast. I then collect the good stuff at 48 hours. This gives me super clean, medium attenuating yeast to store and reuse in the next batch.

My understanding is that by doing this i'm selecting the healthiest cells before they spend 2 weeks under alcohol. I also avoid collect the early and late floc cells, ensuring it performs the same batch after batch.

 

[ChelisHubby]

Thanks for explaining. I am just doing it all in a carboy. I am still a newbie only a dozen brews.

 

[rhys333]

Thanks for explaining. I am just doing it all in a carboy. I am still a newbie only a dozen brews.

Still learning myself

 

[beersk]

A 1 hour lag time would certainly suggest you're over pitching. But over pitching, by at least a little bit, isn't a terrible thing. Pitching onto an entire yeast cake...may be more detrimental, but that's still debatable as well. I wouldn't worry about it after 4-5 weeks for making a starter. Pitch what you got and roll with it. Aerate well and you should be good-to-go.

 

[orangehero]

if our goal is the best beer possible then you need both theory and experience. the wrong theory will prevent you from making good beer. you must have a sold foundation. once you know what's suppose to happen you can build on that. also it is much harder to repeat exceptional beer without knowing all the little details. in a production brewery setting they know how much yeast they are pitching...

No one said theory is not important or necessary. Many production breweries don't have labs or expensive measuring equipment and thus use estimates for a multitude of variables such as oxygenation and yeast counts. The Wyeast article linked in the second reply above about estimating yeast count is written specifically for commercial brewers.

 

[F_R_O_G]

un needed comment

 

[orangehero]

Since you weren't talking about any specific style or strain of yeast, can you describe in general terms what you imagine a perfect, best possible beer to be and in what ways repitching yeast would never allow that to be achieved?

Have you made perfect beer using only fresh yeast packages or a starter? Have you tried repitching yeast and found the resulting beer to have major issues?

 

[rhys333]

A 1 hour lag time would certainly suggest you're over pitching. But over pitching, by at least a little bit, isn't a terrible thing. Pitching onto an entire yeast cake...may be more detrimental, but that's still debatable as well. I wouldn't worry about it after 4-5 weeks for making a starter. Pitch what you got and roll with it. Aerate well and you should be good-to-go.

Thanks for the feedback. Do you direct pitch yourself with good success? I do have a LOT of this wy 1469, and it is one beast of a yeast. Will probably be a good experiment.

 

[rhys333]

As mentioned, i figure around 200ml

 

[jfr1111]

Yeah, that's a lot of yeast for a single regular gravity 5 gallon batch. On the other hand, it spent 4-5 weeks in the fridge. I always try to pitch slurry within 2 weeks (1 week or even a few days is even better, but not always feasible), and I don't harvest massive amount of slurry like you did since I prefer to restart it with a starter and pitch at high krausen if the slurry is old.

Pitch a third of this and watch for your lag time. Some lag time is desirable as you know. I like about 8-12 hours as a lag time.

 

[beersk]

Thanks for the feedback. Do you direct pitch yourself with good success? I do have a LOT of this wy 1469, and it is one beast of a yeast. Will probably be a good experiment.

Yes, I direct pitch almost exclusively. As long as I use it within a month, I feel okay about it. I'm usually over pitching anyway, so I don't worry much. I try not to pitch onto an entire yeast cake, but I've done it a couple times and it seems fine, but it's not best practice.
I usually see 6-8 hours of lag time when I pitch harvested yeast. Sometimes quicker, sometimes takes a little longer, but never usually longer than 12 hours.

 

[jfr1111]

Yes, I direct pitch almost exclusively. As long as I use it within a month, I feel okay about it. I'm usually over pitching anyway, so I don't worry much. I try not to pitch onto an entire yeast cake, but I've done it a couple times and it seems fine, but it's not best practice.
I usually see 6-8 hours of lag time when I pitch harvested yeast. Sometimes quicker, sometimes takes a little longer, but never usually longer than 12 hours.

It's always good to err on the side of overpitching when using slurry and if you are experiencing 6-8 hours lag time, I wouldn't fret too much.

 

[rhys333]

Well I did a quick check through my notes, and my slurry will be 7 weeks old this weekend. I would like to try the direct pitch, but I'm probably pushing it. A small starter may be in order at this point, me thinks. I would like to see how many generations I can get out of this before it goes wonky. I hear top-cropped yeast, if treated the same batch after batch, will keep performing for you without mutating. Not claiming this is true, but it's got me curious!

 

[ol-hazza]

That looks like a huge amount of yeast to me, I only manage to get 3-4 tablespoons from a batch at most..
Are you harvesting trub or am I missing out on a whole heap of yeast?

 

[orangehero]

You should have a quart of slurry if not more from a 5 gallon batch.

 

[ol-hazza]

Half a gallon of yeast from a 5 gallon brew? You must be talking about before the yeast has settled

 

[rhys333]

That looks like a huge amount of yeast to me, I only manage to get 3-4 tablespoons from a batch at most..
Are you harvesting trub or am I missing out on a whole heap of yeast?

I'm harvesting from 1469 west yorkshire. Its one of the true top cropper strains... pure yeast, up to 1/3 pint of it, scooped right off the top. Zero percent trub.

 

[ol-hazza]

Seems im missing out on some yeast then, will have to have another look at my practices

 

[rhys333]

Seems im missing out on some yeast then, will have to have another look at my practices

Might just be the strain you're using

 

[ol-hazza]

Im getting 40ml give or take. Pitching a 3rd of that n getting beer though so cant complain

 

[mbobhat]

They must think it seems like science that way, but it is actually just an over-application of theory. It's better to do a lot of experiments and take good notes. Empirical data will take you a lot farther than theory in this game.

That's the interwebs for ya.

For those that over apply theory, read any of the Classic beer style books particularly Noonan's Scotch Ale. It has tons of information, and historical info to boot. Rather than overanalyze it gives you the tools to Just do It! Best way to learn