Yeast Starter.... Not Starting?

[felten]

Not just that each situation you put the yeast in will differ like Wolfy said, but each strain will behave differently as well.

 

[dustinsullivan]

Not just that each situation you put the yeast in will differ like Wolfy said, but each strain will behave differently as well.

As far as reproduction is concerned, all strains of yeast behave the same way, they reproduce via budding. This means that if the same number of viable cells from two different strains of yeast are placed in identical environments which are conducive to reproduction, they will both produce approximately the same number of daughter cells.

 

[QldKev]

Youve never made a starter and counted the yeast cells to compare the actual numbers to your calculated numbers, or the calculations from any other source?

I got to 10 and stopped counting B)

 

[glenwal]

As far as reproduction is concerned, all strains of yeast behave the same way, they reproduce via budding. This means that if the same number of viable cells from two different strains of yeast are placed in identical environments which are conducive to reproduction, they will both produce approximately the same number of daughter cells.

Why would the fact that they reproduce via the same method imply that they reproduce at the same rate? (Geninue question - not saying you're wrong).

 

[MHB]

I'm curious Wolfy, why do you think yeast calculators like Mr. Malty are "virtually all guesswork with a large amount of error"

Do you have any kind of data to back up this claim?

Cool, then he won't mind providing it for us.

Youve never made a starter and counted the yeast cells to compare the actual numbers to your calculated numbers, or the calculations from any other source?

As far as reproduction is concerned, all strains of yeast behave the same way, they reproduce via budding. This means that if the same number of viable cells from two different strains of yeast are placed in identical environments which are conducive to reproduction, they will both produce approximately the same number of daughter cells.

sulli_42
Curious and curiouser, Wolfy has done a lot of work with yeast propagation, shared that work with everyone and established a solid reputation for knowing what he is talking about.
Who are you? You have been here for about six months all your posts bar 1 appear to be on yeast propagation.

Now personally I am a little dubious about some of the conclusions Mr Malty reaches, even more cautious about some of the assumptions people make when they try to apply the processes, but at least people are starting to recognise the importance of a big healthy pitch and take steps applying that to their brewing.

Do you have a background in the field, you are demanding that people prove assertions based on and linked to well documented research on the subject, had you gone back and read over the material you would have seen where those opinions were formed.

Under ideal conditions the reproductive pathway for yeast is well understood and researched and there are more than a few very good books on the subject. When it comes to applying that to home brewing there I would agree that there is a lot of guesswork and room for error, or to quote Wolfy
Don't stress about too much numbers or calculations, they're virtually all guesswork with a large amount of error, focus on growing healthy yeast as your highest priority, then if you are anywhere even close to the 'right' numbers/volumes/counts, it will take care of the rest.

So back at you, you have a different opinion, what is it based on, or in your own words Do you have any kind of data to back up this claim?
Mark

 

[QldKev]

Free plug for Sulli_42
Visit http://www.yeastcalc.com



To me the biggest issue is there is more than 1 calculation out there.
Person A does some lab testing and proves a given rate,
Person B does some testing and proves a different rate.
Person B may do another test a few years later and prove the prior test inconclusive, and comes up with a new rate...

It's science, it's not an exacting process. At least all rates are fairly common.

QldKev

 

[MHB]

Yes I have seen that, I believe his first post.
Still begs the question, what are his qualifications, what are the calculation based on and why should we believe him.
Wolfy (and I dont always agree with all his conclusions) has been here for a long time the development of his ideas has been open and has involved a lot of hands on brewing as well as discussion with other brewers simply put it works.
Both Mr Malty and YeastCalc looks pretty flash, but bases on my own experience and research look a lot like lab results where everything is perfectly controlled and works according to a plan. The real world is often a hugely different place.
Mark

 

[QldKev]

It would be good to be able to talk with a qualified pro in the area,

I've always had the question, when stepping up starters, would each step technically be deemed a new generation of the yeast?
Allowing if :
A - Stepped at high krausen, and
B - stepped after the yeast has dropped.

QldKev

 

[dustinsullivan]

sulli_42
Curious and curiouser, Wolfy has done a lot of work with yeast propagation, shared that work with everyone and established a solid reputation for knowing what he is talking about.
Who are you? You have been here for about six months all your posts bar 1 appear to be on yeast propagation.

Now personally I am a little dubious about some of the conclusions Mr Malty reaches, even more cautious about some of the assumptions people make when they try to apply the processes, but at least people are starting to recognise the importance of a big healthy pitch and take steps applying that to their brewing.

Do you have a background in the field, you are demanding that people prove assertions based on and linked to well documented research on the subject, had you gone back and read over the material you would have seen where those opinions were formed.

Under ideal conditions the reproductive pathway for yeast is well understood and researched and there are more than a few very good books on the subject. When it comes to applying that to home brewing there I would agree that there is a lot of guesswork and room for error, or to quote Wolfy
"Don't stress about too much numbers or calculations, they're virtually all guesswork with a large amount of error, focus on growing healthy yeast as your highest priority, then if you are anywhere even close to the 'right' numbers/volumes/counts, it will take care of the rest."

So back at you, you have a different opinion, what is it based on, or in your own words "Do you have any kind of data to back up this claim?"
Mark

Whoa...simmer down mate. I'm not trying to disrespect anyone, and I never said I had a differing opinion. In fact I agree with almost all of what Wolfy has to say. I just disagree with the rhetoric in some of his statements; namely that yeast growth calculations are "virtually all guesswork with large margins of error." White and Zainesheff et al. have done a significant amount of real science, i.e actual counting of yeast cells in various sized starters, in order to develop the algorithms that are used in their "calculations", and I could post up half a dozen mathematical formulas from various text books on yeast all based on hard science.
I myself perform cell counts on all my yeast starters every time I make a beer, and the numbers are consistently within 50 billion cells of what the calculations are. I would never claim that a mathematical formula can produce exact predictions of cell counts, they are most definitely ball park estimates, but for someone to say in one breath that yeast calculators are all based on guesswork with huge margins of error and then offer up advice on what size starter to make or offer up a stepping regime based on his "calculations" seems rather contradictory. That's all.

Fire away.

 

[Screwtop]

As many will know I rarely post re beer related stuff anymore, due to the chest beating and pissing contests on these forums, mostly by google brewers with little experience! So I am not about to enter this debate, but would like to point out one important factor for all brewers weather you are making a starter of propagating yeast (there does seem to be a lot of confusion here). Stepping up yeast colony cell counts, decanting and pitching the slurry is pitching yeast slurry, not making a starter. Leaving starter wort and yeast on a stirplate for days until the yeast has dropped out and pitching this - is pitching yeast slurry and beer which could well be oxidised.

Inoculation Rate is important, the amount of yeast budding/propagation/growth depends upon how many cells are pitched, and the volume, and the gravity of the wort it is added to.

This is advanced stuff, a bit hit and miss for most novice brewers.

As Wolfy says:

I know of only one home brewer (and he's on the UK forums and not these ones) who actually counts yest cells, for the rest of us we are all dealing with 'educated guesswork'.

From Chris White and Jamil Zainasheff's Book - Yeast The practical guide to Beer Fermentation.

The most important thing to know about starter size is that the inoculation rate affects the rate of growth. In other words, the pitching rate'' of your starter has a big effect on the amount of new yeast cells you will see from any propagation. It is not the volume of the starter that is important, but how many cells you add in relation to that volume. Too high an inoculation rate, and you get very little growth. If you use too low an inoculation rate, then you are not really making a starter, you are fermenting beer.

Ideally, you want to grow your yeast in a large enough volume of wort to ensure optimal, yeast health and to get a decent amount of growth for your trouble.

There are formulae contained in the book for determining the Yield Factor, and charts outlining Inoculation Rate Yield Factors. I suggest anyone serious about yeast propagation and stepped starters should get themselves a copy and rely less on opinions found on forums such as this.

Screwy

Fire Away! ............. don't bother, I don't give a shit!

 

[Dazza88]

Yep, great book is Yeast. So truman, did you get any success with your yeasties? Lol.

 

[dustinsullivan]

Fire Away! ............. don't bother, I don't give a shit!

Nice...glad to see your not into the chest beating and pissing contests.

 

[Wolfy]

Whoa...simmer down mate. I'm not trying to disrespect anyone, and I never said I had a differing opinion. In fact I agree with almost all of what Wolfy has to say. I just disagree with the rhetoric in some of his statements; namely that yeast growth calculations are "virtually all guesswork with large margins of error." White and Zainesheff et al. have done a significant amount of real science, i.e actual counting of yeast cells in various sized starters, in order to develop the algorithms that are used in their "calculations", and I could post up half a dozen mathematical formulas from various text books on yeast all based on hard science.
I myself perform cell counts on all my yeast starters every time I make a beer, and the numbers are consistently within 50 billion cells of what the calculations are. I would never claim that a mathematical formula can produce exact predictions of cell counts, they are most definitely ball park estimates

That makes you the 2nd home brewer (that I know of) who actually counts yeast cells, and that adds a deal of credibility to the calculations that you've provided. I'd suggest you post the yeast cell-count information on your website, including what methods you use and what the results were compared to the calculations for each starter you make, it adds both credibility and allows others to see - and hopefully understand - the margins of error involved. However from what I understand by reading the 'Yeast' book even cell count techniques have limitations and large error margins.

The point I was trying to make in this, and several other threads/discussions that I also know you've participated in, is exactly what you said above: a mathematical formula can not produce exact predictions of cell counts, they are ball park estimates that have decent margins of error. I may have used more colorful language and I may have said it in a way that offended you (and your calculations) but that was not my intent.

What I was trying to suggest to Truman when he said this:

I was going to start with a smaller wort volume but when I put the numbers into yeast calc it had my inoculation rate at over 260. I've read on here before that you need to keep it at between 50-100 so I increased the wort volume until I got below 100. If someone could explain which is correct that would be appreciated.

Was the following (or would have been if he'd not already started with his starter):

• Chill mate, you're within the right ball-park everything will be fine.
• The calculation you used is based an an assumption you made about how many cells you have, and can never be more accurate than the guess you made at the start.
• You don't actually know what your inoculation is because the calculation has given you a very rough estimate based on your guess at how many cells you have.
• You've got a small sample there and it's likely not so fresh, so its quite probable that you have fewer cells than you guess, and it's always best to be conservative and assume that things are on the low side and not the high side of things.
• Even if your inoculation rate is high, it does not really matter because we're home brewers not scientists or commercial brewers trying to extract the maximum theoretical growth at minimum cost/volume, the yeast will grow the same for you anyhow.
• If you give the yeast the nutrients and conditions they need, the yeast will grow to essentially the same number of cells in that volume as long as your inoculation rate is anywhere close to what it 'should' be.
• By being concerned about what some calculation said (that the inoculation rate was 'too high') you overlooked the simple fact that if you are unsure about your yeast health, viability and cell count, it is much better to start with a small volume starter than a big one. (He was going to do 50ml, but went to 250ml because a 'calculation' told him that was the 'right' answer.)
• Having a high inoculation rate - especially for the fist step of a starter process - is not a a bad thing, it will not hurt the yeast, and it will likely do more good than bad since it will help your potentially unhealthy and half dead yeast out-compete any bugs that may have gotten into your starter.
• Go with what you think it sensible and logical, don't be pedantic about what some formula says, grow good yeast and be close to the right estimates and you'll be totally fine.

I was trying to add some perspective for those who get more caught up with the idea that some magic formula will give them the 'right answer' - because of the wide range of factors involved - all they need to do is to get within the right 'ball park estimate' (of starter size, inoculation rate, slurry volume etc) and if their yeast is viable and healthy it does not matter what exact cell count is predicted by the formula, or what results a cell count gives - because being in the right 'ball park estimate' is good enough to produce good results. Use the calculations as an estimate and a basis from which to work - but realize they are an estimate. Working with the equipment you have, rounding volumes/counts up/down to make them easy to deal with, and most of all concentrate on yeast health makes things easier, less stressful and the yeast will take care of everything else.

but for someone to say in one breath that yeast calculators are all based on guesswork with huge margins of error and then offer up advice on what size starter to make or offer up a stepping regime based on his "calculations" seems rather contradictory. That's all.

I don't think I said anything even close to that in this thread, and totally stand by my initial advice in this thread: get a refractomer and check the gravity and you will know - without any guesswork - if the yeast has fermented out your starter.

Had I made any suggestions in regard to starter or step sizes, my logic would have gone something like this:
Throw numbers at Mr Malty and see what he says for the starter size required, keeping in mind that for a standard gravity batch of ale, you want a starter in the range of about 1.5-2.5L.
Have a 2L flask, that's more than adequate for the task, even if Mr Malty wants slightly more or less, so lets call it a 2L starter.
To get to 2L from your very small and potentially not very healthy yeast sample, using a couple of steps is probably the best way to go, so that we keep the inoculation rate within resonable bounds, but don't have too many steps or push things too far either way.
Anything between about 100ml and 300ml is more than adequate to setup up to our last step of 2L.
Do I want to pitch what could be a billion or two not so healthy yeast cells into 250ml? I could, but it would probably be better for the yeast and my sanitation to do another step first, so lets start with something smaller, say 50ml.

I'd suggest that for many home brewers and those new to growing their own yeast, using logic like this is significantly easier than working with a moderately complex set of numbers like those on YeastCalc. I was also going to presume that YeastCalc would come up with more-or-less the same setups/answer/cells anyway, but while MrMalty suggests 1L starter is adequate, my own assumptions (maximum cell density in a starter = 100million cells per ml) suggest 2L, YeastCalc wants a 2.6L starter. So I'll go back to saying, that yeast calculations are educated guesswork with large margins of error and from experience I know that a 2L starter works great and hence it does not really matter what any forumla has told me is right or wrong.

 

[kevo]

Soooo.... back to the OP....

Would people say based on whats been discussed above that the volume of the starter was excessive for the quantity of yeast being used to inoculate?



Kev

 

[felten]

As far as reproduction is concerned, all strains of yeast behave the same way, they reproduce via budding. This means that if the same number of viable cells from two different strains of yeast are placed in identical environments which are conducive to reproduction, they will both produce approximately the same number of daughter cells.

Sorry I should have been more specific, I was more referring to using the calc to estimate viability. Jamil has said himself that strains will differ in that regard, with some losing more viability over time than others.

 

[Wolfy]

Would people say based on whats been discussed above that the volume of the starter was excessive for the quantity of yeast being used to inoculate?

The most important thing 'we' need to know to answer that is how many viable yeast cells 'we' are starting with, so I'd be interested to know what Truman used for his estimate.
'We' don't now how much yeast slurry was there in the 25ml vial, how was it stored, how was it washed etc. so any cell number estimate 'we' make is a wild guess.
It also depends on how good sanitation/sterilization of the wort and equipment was.

Since there is nowhere else to go, 'we' must resort to calculations, estimation and guesswork:
MrMalty suggests 46% viability for yeast slurry stored for 1 month, assuming 5mls of compact, clean, washed yeast slurry in the 25ml vial, I would guess 'we' would be starting with somewhere between between 2 and 5 billion cells.
(Use the sliders on MrMalty's repitch tab to see how the numbers change for different slurry conditions and the viability dates at the top to help make own guess).

Now you need to look at what is the appropriate starter volume for the number of cells, and the best reference for this is the 'Yeast' book page 126-146 (which includes the quote from Screwtop above), the YeastCalc page will also give you lots of numbers to work with. Essentially most will conclude what 'we' are doing is well within what is considered acceptable.

However, now 'we' come to two important but impossible to measure or calculate intangible things to consider:
1) How accurate was the starting cell estimate, given that Truman has posted here, it leads me to suspect that he could be a little bit unsure about his sample, maybe the washing process was not ideal, or it was not stored in the fridge every day, any other unexplained factors which could indicate that the number of yeast cells in the original sample might be significantly lower than estimated above.

2) How good was the sanitation (most home brewers do not work in a sterile environment) of the wort and equipment.

Both of these factors could suggest that a smaller volume starter may have been 'better'. A small amount of not-very-healthy-yeast in a larger starter has more trouble out-competing infections, and if we have significantly less (or more) yeast cells then the health of the starter can suffer. However, using a smaller starter (50ml was suggested) means that there would be an extra step in the starter-making process, inviting extra risk of contamination from the wort or equipment used in that step. So it's a balance between which one poses the less risk and is more likely to produce a good starter at the end of the process.

 

[Truman42]

@ Wolfy. Thanks very for taking the time to post some very informative replies with lots of helpful advice. It's very appreciated.

In answer to your question on how I arrived at my cell count I put the date of my slurry into Mr Malty, left the sliders at default and entered my OG and batch size.
This told me I needed a yeast slurry of 167 mls containing 163 billion cells. (figures are approx)
So I simplified it and made it 1ml per 1 billion cells.
I then entered 25 billion cells into Yeast calc at 95% just to cover a bit more loss, and then entered my first starter size and increased it until my inoculation rate was above 50. Which was 250 ml.
My slurry was rinsed well and I had it stored in the fridge for a month and was full to the top with only a few mls of wort on top.
But as you said in your post my 25ml slurry was probably well under 25 billion cells, which is something I will consider in the future.
Thanks again.

 

[Dazza88]

So did you persist with it or chuck it?

 

[robbo5253]

So what happened with the starter?

 

[Yob]

I then entered 25 billion cells into Yeast calc at 95% .... and I had it stored in the fridge for a month

sorry? did you use the "calculate viability from date" thingamy? No u'king way it's at 95% viability at 1 month...

er.. unless I misunderstood something coz Ive 'ad a few..

'king pool night ya know... 'tuedy's te nu friday ya know... mumble mumble..