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1/4 Smack Pack Starter Step Advice

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iralosavic

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G'day,

I've read most of the threads on here on the topic, but I just need some final advice.

I plan on splitting 125ml smack packs in 4, so let's say around 30ml. For my theory, I have used a 6 month age (10% viability).

That leaves me with 2.5b viable cells.

Now, reading around I've concluded that it's a safe bet to increase steps by 4xvolume for lagers and I assume this is based on the slurry volume not the cell count (please stop me here if I'm wrong!).

So for the above scenario and a target final population of 450b, would I be on track doing the following:

1. 120ml
2. 480ml
3. 1900ml
4. 4500ml
= 457b cells.

I have a 1L and 5L flask, so my plan would be to accumulate the first 2 steps in the 1L, then pour the lot into the 1900ml starter in the 5L, then once that is ready, chill, decant, and add the final 4.5L, let it ferment to high krausen and then pitch the lot into the awaiting beer.

Any criticisms/suggestions most appreciated!



Cheers,
 

Thefatdoghead

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G'day,

I've read most of the threads on here on the topic, but I just need some final advice.

I plan on splitting 125ml smack packs in 4, so let's say around 30ml. For my theory, I have used a 6 month age (10% viability).

That leaves me with 2.5b viable cells.

Now, reading around I've concluded that it's a safe bet to increase steps by 4xvolume for lagers and I assume this is based on the slurry volume not the cell count (please stop me here if I'm wrong!).

So for the above scenario and a target final population of 450b, would I be on track doing the following:

1. 120ml
2. 480ml
3. 1900ml
4. 4500ml
= 457b cells.

I have a 1L and 5L flask, so my plan would be to accumulate the first 2 steps in the 1L, then pour the lot into the 1900ml starter in the 5L, then once that is ready, chill, decant, and add the final 4.5L, let it ferment to high krausen and then pitch the lot into the awaiting beer.

Any criticisms/suggestions most appreciated!



Cheers,
Id put the 30ml in a 1L starter for more growth rather than 120ml. As shown in "yeast" a large amount of yeast in a small starter promotes a very small amount of growth. The next step up would need to be a big one for lager numbers.
Im thinking of trying a 9L starter with a full wyeast pack on a stir plate. I'll try the stir plate with water first then get into it with wort if its spinning ok.
 

iralosavic

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I wouldn't classify 2.5 billion cells as a large amount of yeast though. It may be 30mls, but only 10% viability.

Also, I'm trying to save money by splitting packs. The amount of DME or extra grain for surpless wort required to make huge starters starts to put the whole purpose of splitting up for question.

My plan is to use DME for the first 3 steps and wort for the fourth. Should only need around 2.5-3L plus dilution and only consume a couple hundred grams of extract.

I didn't mention it, but my batch size is around 20L to the fermenter. I'm happy to toy with the idea of a larger initial starter, but I was under the impression that doing so increased the risk of other bacteria getting a stronger hold.
 

Steve@PMF82

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Id put the 30ml in a 1L starter for more growth rather than 120ml. As shown in "yeast" a large amount of yeast in a small starter promotes a very small amount of growth.
If the yeast sample is 6months old and an estimated 10% viability as iralosavic says, then pitching that into a smaller amount of wort will result in healthier yeast. Pitching a few old cells straight into a 1L starter you will most likely be breading stressed yeast.

iralosavic the procedure you have outlined for growing your yeast looks good to me.
 

kelbygreen

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Not to clued up on the whole starter thing. But alot of guys use the mash runoff from there MT for the starter. So when you reach volume in your kettle or if you drain the tun and leave it sit for a while then drain the last lt or so then that gets frozen and used as a starter later on. Just boil it very well first. I have not done this before myself but if you really worried use few more dollars in grain and make a few more lts and run that off for your starter.
 

Wolfy

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...
That leaves me with 2.5b viable cells.

Now, reading around I've concluded that it's a safe bet to increase steps by 4xvolume for lagers and I assume this is based on the slurry volume not the cell count (please stop me here if I'm wrong!).

So for the above scenario and a target final population of 450b, would I be on track doing the following:

1. 120ml
2. 480ml
3. 1900ml
4. 4500ml
= 457b cells.

I have a 1L and 5L flask, so my plan would be to accumulate the first 2 steps in the 1L, then pour the lot into the 1900ml starter in the 5L, then once that is ready, chill, decant, and add the final 4.5L, let it ferment to high krausen and then pitch the lot into the awaiting beer.

Any criticisms/suggestions most appreciated!
I believe the yeast book suggests that steps of 10x are the most common, so you might be a little conservative and have a an extra step.

In addition I also believe that the step-size is based on cell count.
However, because as home brewers, we start with yeast in super-concentrated form (a smack pack or vial) the first step-size is often miscalculated - step sizes (based on volume) assume the previous step has the same maximum cell density as the next, which is not true for the first step in a starter made from a smack pack or vial.

Working on cell counts, 10x growth factors, and assuming a maximum cell density of 100million cells per ml in your starter (which is probably valid assuming you have a stir-plate and ample nutrients):
2.5billion
1: 250ml = 25billion
2: 2.5L = 250 billion
3: 4.5L = 450billion

However that leaves the last step with a much smaller growth factor than the previous two, so we may as well make things a bit more even, with something like:
2.5billion
1: 120ml = 12billion (growth factor 4.8)
2: 800ml = 80billion (growth factor 6.6)
3: 4.5L = 450billion (growth factor 5.6)

Of course we are making many assumptions, but anything in that sort of range will likely produce much the same end result, which whatever cell count you'll get from the 4.5L starter.

In addition, I'd not recommend chilling or decanting spent-starter-wort during the starter process, it's unnecessary and - I'd suggest - does more harm to the yeast you are trying to grow than any benefit it offers you. 120ml in a 1L flask is a very small volume, so that's likely to not work well either.
With 3 steps, I'd suggest using a glass-jar or similar for the first step, then the 1L and then the 5L flasks.

As kelbygreen suggested, there are various ways you can save money on your starter wort (compared to using LDME), I tend to use kettle-dregs or discounted tins of goo for most of mine. The hops might not be ideal but it's much cheaper. :)
 

dr K

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My (fairly obvious question) is ..why?
14 years ago, when I was stupid enough to start all grain brewing (a diificult thing in those days) a vial or smack pack, in fact it just pre-smack-pack days was from the local anything between $16 and $22 each (and they were usually on the old side), thats about $35 in todays currency. Yes there was a very good reason to split, to farm, to re-use.
Looking around yeast starts off at at $10 these days, you may have to pay postage but you can always buy a few.
Still too expensive?
If your wort was claen, your vessels clean and your fermentation clean you will have good clean beer, and as a bonus good clean yeast in buckets.
Even if you had masses of trub carry through it is a far simpler matter to do some basic slurry washing (look it up) to get a pretty good base for your next beer, it is certainly far less work than multiple growth steps, and remeber every growth step brings with it the chance of contanimation, or worse, mutation.
I, personally, do not re-use my yeast, nor do I risk dicing and growing, thtat is a personal choice. Most of the good brewers I know take a single pack and grow it up for a double or even triple batch and thats it, but again thats a personal choice.
The most critical part of brewing is exactly that, brewing, and brewing is fermentation, its all about clean, haelthy yeast and proper temperature regulation, the one part you don't want to skimp on is fermentation

K
 

stux

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I do what you want to do.

I use http://yeastcalc.com to work out my steps

Normally try to get it in 3 steps, remember infection risk is real, so yeast health needs to be traded against number of steps

You can jump big early, the lag is larger though

24-36 hours or so on the large steps
 

JDW81

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When I finish my mash and have my desired pre boil volume I put a container under the tap on my mash tun and let the mash dregs trickle in. By the end of the boil I've usually got about 1.5 - 2 litres of wort. It goes in the fridge and the boiled wort is drained into a cube. I do a quick clean up, boil the collected runnings and then make a starter of whatever size I need. What ever doesn't get used goes into the freezer and it given a quick boil when needed to step up to a larger size.

Doesn't cost me any extra and I get the double bonus of making a starter with the same wort as the beer. No more buying DME or goo. It doesn't save much, but it all counts.

I think your starter volumes look ok. It is what I do and works a charm every time.

JD.
 

iralosavic

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Thanks all for your effort in replying. Dr K: a valid question and one that I'm trying to figure out the answer to. Many people have no issue with yeast health after stepping up stored samples and their beer turns out none the worse for it. So for me, it becomes a question of economics in terms of extra grain or DME vs buying more yeast. Once I figure out my starter steps, I'll be able to better make these calculations and finally decide if splitting by 4, 3, 2 or not at all will be best for me.

Wolfy: thanks for your post, mate. I'd rather not decant, but with your suggested steps 120+800+4500 I end up with a volume greater than my 5L flask and am stuck as to what to do here. Any ideas?

Thanks everyone.
 

Steve@PMF82

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Thanks all for your effort in replying. Dr K: a valid question and one that I'm trying to figure out the answer to. Many people have no issue with yeast health after stepping up stored samples and their beer turns out none the worse for it. So for me, it becomes a question of economics in terms of extra grain or DME vs buying more yeast. Once I figure out my starter steps, I'll be able to better make these calculations and finally decide if splitting by 4, 3, 2 or not at all will be best for me.

Wolfy: thanks for your post, mate. I'd rather not decant, but with your suggested steps 120+800+4500 I end up with a volume greater than my 5L flask and am stuck as to what to do here. Any ideas?

Thanks everyone.
When i step up to a big starter i do not refrigerate to drop the yeast out either. When i get to my starter vessel capacity i will just let the yeast drop out naturally at ferment temps, can take a day or 2 depending on the strain. I have not used any really low flocculation strains so cant comment there.
Apparently it is better when growing the yeast to try and keep them in the growth phase for all the steps and only let them drop at the last step if just planning on using the slurry.
Depends how anal you want to get about the whole thing. For my money concentrating on sanitation is the most important thing and i still consider my yeast i have grown pretty fresh even if i have let it sit for a few days in temp control environment along the way. Ferment is always up and running 6 - 8h later. But as always YMMV
 

Wolfy

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Wolfy: thanks for your post, mate. I'd rather not decant, but with your suggested steps 120+800+4500 I end up with a volume greater than my 5L flask and am stuck as to what to do here. Any ideas?
As per my starter-photo-thread (that is around here somewhere) I make the 3 starters at the same time, starting with 4500ml, then decant the 800ml into its container and the 120ml into its container (and then heat-sterilize them all) that way the total final volume is 4500ml (not 4500+800+120).
 

stux

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Thanks all for your effort in replying. Dr K: a valid question and one that I'm trying to figure out the answer to. Many people have no issue with yeast health after stepping up stored samples and their beer turns out none the worse for it. So for me, it becomes a question of economics in terms of extra grain or DME vs buying more yeast. Once I figure out my starter steps, I'll be able to better make these calculations and finally decide if splitting by 4, 3, 2 or not at all will be best for me.
Re the cost of DME, I ran into the same problem.

Now I only use DME to top up my starters if I don't have quite enough real wort, generally would only use 100g or so, even for large 6L of wort starters (total)

So, at the end of my BIAB brew I pour all the leftover kettle dregs into a 5L flagon and refrigerate. Then later I decant the clear liquid into a jug. I might repeat and decant again...

I end up getting about 50% of my kettle trub back as starter wort, so for a 60L batch I might get 3L of wort back.

The wort would generally be about 1.050, so I dilute to 1.040-1.037 (ie 3L -> 4L), and then if I need any more liquid add water and for each 100ml add 10g of DME.

Then I boil it for 15 mins, and cool.

End result, I only end up using 50-100g of DME and a quarter smack pack to make a triple batch starter, and get to ferment with what I regard as virgin yeast
 

iralosavic

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Wolfy: according to yeastcalc, from 2.5b and the 3 steps mentioned we'd only have 334b cells at finish?

Stux: excellent suggestion. I was planning on adding more grain to compensate, but hadn't thought to attempt collecting and clearing the kettle losses. I usually don't lose much though, due to hops being contained in a bag. I'll collect what I can from my next ale and freeze it.

Cheers
 

cdbrown

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In addition, I'd not recommend chilling or decanting spent-starter-wort during the starter process, it's unnecessary and - I'd suggest - does more harm to the yeast you are trying to grow than any benefit it offers you. 120ml in a 1L flask is a very small volume, so that's likely to not work well either.
With 3 steps, I'd suggest using a glass-jar or similar for the first step, then the 1L and then the 5L flasks.
When decanting you are putting the yeast into a proper 1.038ish wort, if your just pouring the starter into the next you are diluting the next step. EG going from step 2 to 3 you are adding a 920ml of lower grav to 3580ml of the OG. Are you taking this into consideration at all?
 

Wolfy

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Wolfy: according to yeastcalc, from 2.5b and the 3 steps mentioned we'd only have 334b cells at finish?
Any 'calculation' that helps you get an idea of what you should be doing, and helps you be able to repeat the process is useful, however your procedures are much more important than being overly concerned about 'calculations'.
If your yeast is healthy, step size is resonable, you supply enough nutrients and use a stir-plate; the cell count is going to be a function of the starter volume more than anything else.

No matter what 'calculations' say the yeast will reproduce as well as they can in the conditions they are given, 'ideal' conditions equate to maximum growth. However, from past experience brewers have learned that infections are much more likely if starter-steps are too large (there is not as much yeast to out-compete the bugs). If you could keep it absolutely sterile you could probably just pitch your 1/4 pack into the 4.5L and after a lag-period you'd probably end up with about the same number of yeast cells.

As home brewers, we are not actually counting yeast cells, and all of these 'calculations' are really very very rough estimates, with a very large margin of error. As a consequence, it's best to focus primarily on breeding healthy yeast and keeping unwanted infections out. Once that is done, you need only to have your starter volumes anywhere within the 'correct' ball-park range to (usually) get good results.

This is also why I use the very simple assumption that in my starters will reach the maximum cell density 100million cells per ml, no need to worry about inoculation rates, step multipliers or anything else like that - keep it simple and basic, but it still ends up being in the same rough estimated ball-park volume at the end.

Rather than being overly concerned about pedantic calculations, I'd look at your situation this way:
  • You're brewing a lager, so you want the biggest starter that you can make.
  • With your equipment - a 5L flask - that is about 4.5L.
  • To get to 4.5L from your old 1/4 smack pack, it's best to use 2 or 3 steps.
  • The first step should be small ~100ml so that you reduce the risk of infection.
  • This leaves the other step somewhere between those about ~1L is good.
Then if you focus on yeast health and sanitation, you've done the best you can with your gear and situation to grow the 'right' amount of healthy yeast for your beer.

I have SWMBO watch for discounted cans of goo at the Supermarket or Kmart, usually it works out $5 to $10 for about 25L of starter, and the tins of goo store in the refrigerator until I need to make the next batch of starters.
 

iralosavic

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Cdbrown poses an interesting observation. Each cumulative starter will be diluting the effective gravity of the solution. I wonder if it is just nothing to worry about because each step is many times larger than the last, therefore minimizing the rate of dilution?

Woody: thanks again for your time and wisdom. You've given me a lot to think about. I guess I've just been more worried about being unable to grow enough yeast from a sample than I have about keeping it simple. If I do it and it works, then that's that - and I guess you know it works for you already.
 
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