If I were to harvest yeast and keep it going, how do I know how much to use in a brew? I've never gone beyond the smak packs or dry yeast packets. Is there a way to work it out? Or is it for example a couple of spoons?
knowing how much yeast to use?
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Check out the "Calculators" at the top of this page. There's one there for yeast.
Enjoy! :thumb:
Enjoy! :thumb:
Overbuilding your liquid yeast starter is more reliable than harvesting slurry post-fermentation as far as knowing how much you've got goes. Then when the calculator asks you how many cells were in there to begin with you have a reasonably good idea. This calculator allows you to enter how much you want to overbuild by (100bn is typical) then you note how much the calculator has increased your starter volume by versus a zero overbuild and save that much back in the fridge for later.
As a rule of thumb for a batch of 23l ale less than 1.050-ish SG you can do a 1.5l starter, save back 0.5l and pitch 1l.
As a rule of thumb for a batch of 23l ale less than 1.050-ish SG you can do a 1.5l starter, save back 0.5l and pitch 1l.
So I don't actually intend on harvesting any yeast actually (well not right now anyway), but I have a WYeast starter in the fridge which I didn't use. So I was thinking about growing it, by adding fresh DME mix to the yeast from time to time. Then when I have enough clean yeast to separate to a ball jar I can siphon some out and store it.
When it becomes time to use the yeast, would it be a case of spooning some into a fresh starter and waiting for it to activate and then pitch?
I saw the calculator, but I wouldn't know how many cells are in there? It was a single smak pack, which would (I'm guessing) be 100b cells, but the starter was on the stir plate for over a week with DME. It's now in the fridge so has settled. I was going to wake it up with some fresh DME to grow it some more.
But, how do I know what the cell count is and how much to pitch to my next beer?
FYI, this is not really me trying to stretch yeast. It's a learning exercise and experiment really.
When it becomes time to use the yeast, would it be a case of spooning some into a fresh starter and waiting for it to activate and then pitch?
I saw the calculator, but I wouldn't know how many cells are in there? It was a single smak pack, which would (I'm guessing) be 100b cells, but the starter was on the stir plate for over a week with DME. It's now in the fridge so has settled. I was going to wake it up with some fresh DME to grow it some more.
But, how do I know what the cell count is and how much to pitch to my next beer?
FYI, this is not really me trying to stretch yeast. It's a learning exercise and experiment really.
Does it really matter how many billions of yeast cells are present after we have "enough"? I may be corrected (as usual) but I can't recall anyone suggesting that having too many yeast cells is a "bad" thing!
The first few seconds of this video explains why the guy recommends a Yeast Starter ...
[ame]https://www.youtube.com/watch?v=jMhFerNTwbQ[/ame]
... and I have always presumed that making a yeast starter in line with this will give me enough yeast cells to pitch it into a 23 litre brew; even when using recovered yeast.
So far, it has worked out okay. :thumb:
I don't know that it would necessarily fall under the category of a "bad thing" but I believe over pitching can affect the final beer. This is probably more of an issue with some beer styles than others.
My understanding is that a lot of the ester production takes place during the growth phase of fermentation when yeast are multiplying exponentially. If you over pitch a beer which you want a big ester profile from then you may get less esters than you wanted.
I think it is common practice in some quarters to slightly under pitch some wheat and Belgian styles where you want a bit ester flavour.
Will this result it a bad beer, probably not, but it might result in a different beer to the one you wanted.
strange-steve
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I think I'm struggling to get my actual question across, that or I'm struggling to understand the answers.
Let's say for example, I have a nice big jar of yeast labelled up in the fridge dormant, which I've multiplied and multiplied over time. Let's say for arguments sake, it's 2L of yeast. Which is of course WAY too much to pitch into a beer.
My question is, how do I know how much of that yeast to put into a starter for a beer?
Let's say for example, I have a nice big jar of yeast labelled up in the fridge dormant, which I've multiplied and multiplied over time. Let's say for arguments sake, it's 2L of yeast. Which is of course WAY too much to pitch into a beer.
My question is, how do I know how much of that yeast to put into a starter for a beer?
I think your question is clear enough but not sure how to answer it. Calculator s are fine if you start with a known amount and keep good records but an error must creep in with every new starter you make. I think I've seen estimates of number of cells per weight of yeast slurry but don't have details to hand.
strange-steve
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First you need to know roughly how many yeast cells you need, the usual recommended amount is 0.75 million per ml of wort per ðplato. Now you need to know the yeast density of the slurry you have, which is the tricky part because it requires a lot of guess work. But as a starting point you could assume roughly 1 billion cells per ml of thick slurry, ie the stuff that settles at the bottom.
Have a look at the bottom of this page which has a bit more detail.
Have a look at the bottom of this page which has a bit more detail.
I see.. I think this looks a bit too much like guess work for me.
I think I'll just go with a starter which is larger than needed and save just enough to make another starter and just keep going like that, at least I'll have a better idea of what I'm doing.
My main idea here (aside from just learning about yeast), is that Wyeast is quite expensive and a pain in the backside to get hold of. I have to order from geterbrewed and pay about ã1000 for delivery and wait until next xmas. So if a recipe says wyeast wheat is the best for that recipe, I can't make the beer on the fly I have to wait. And I don't to bulk buy yeast at that cost. So I'd like to keep a yeast going, so it's always available when I need it.
Maybe a US ale wyeast, and a wheat yeast. And just keep them going for as long as I can.
Would you say the best way to achieve this is not to reproduce until I have loads of it, but to over make the starter and keep 10% back for another starter next time?
I think I'll just go with a starter which is larger than needed and save just enough to make another starter and just keep going like that, at least I'll have a better idea of what I'm doing.
My main idea here (aside from just learning about yeast), is that Wyeast is quite expensive and a pain in the backside to get hold of. I have to order from geterbrewed and pay about ã1000 for delivery and wait until next xmas. So if a recipe says wyeast wheat is the best for that recipe, I can't make the beer on the fly I have to wait. And I don't to bulk buy yeast at that cost. So I'd like to keep a yeast going, so it's always available when I need it.
Maybe a US ale wyeast, and a wheat yeast. And just keep them going for as long as I can.
Would you say the best way to achieve this is not to reproduce until I have loads of it, but to over make the starter and keep 10% back for another starter next time?
BrewUK dispatch yeast by 1st class post and charge ã2.95 for a single yeast pack delivery. Quite a few times I've left it late and pinged them an embarassed 'I'm an idiot' email and they've ensured it's sent out the same day.
Handy to know, thanks. I'll bear that in mind.
Still would be good to keep yeast going if it's the kind I use all the time.
GEB don't seem to care TBH. I missed a couple of things off my order yesterday and wanted to order 2 more items (individually as I forgot twice), I emailed asking if I could purchase them as collection and for them to bundle the items into my previous order which I paid delivery for. No response. So I just ordered anyway (twice) paying for 2 more lots of delivery.
Then I emailed them saying I need them asap, could I have next day delivery... they said, yes.. for an extra ã6!!! Bearing i mind I'd paid three lots of delivery for an order that doesn't add up to the 30kg 1 delivery slot weight!!
That's my last order with GEB. I responded to their email asking for additional payment for next day delivery, and explained that I'd made 3 separate orders in the same day totalling ã17.85 of delivery alone. And I said "Could we both agree that on this occasion I have paid enough delivery to warrant next day at not additional cost?".
I got no response at all, and just had an automated email saying that my order has been dispatched on parcel force 48 hour delivery.
Hi!
Do you mean that you've used the yeast several times, each time keeping a portion for the next starter, or that you've used successive builds to achieve a big starter?
This throws up two memories:
1. Many years ago, I asked a Consultant who was selling "Quantitive Risk Assessment" how he could put a figure on the chances of a risk being realised. "We use Monte Carlo Numbers." he said and walked away.
Puzzled at the answer and being only a lowly Operator at the time, I asked a mate "WTF are 'Monte Carlo Numbers'?" and he in turn asked me what Monte Carlo was famous for and explained the use of an "educated guess".
2. I think it was Sam Goldwyn the famous Film Mogul who was berating one his Film Directors about the increasing expense of a film. Apparently, he was heard to say "A million dollars here and a million dollars there and it's not long before we're talking big money!"
I feel exactly the same about my home brew efforts to make a Yeast Starter. :thumb:
1. How many yeast cells are present at the start and the end is at best an "educated guess" based on what has worked for me in the past.
2. If I bothered with "calculating" the yeast cells and got the start figure wrong by a couple of billion how the heck would I know how many are there when the wort is cool enough for the yeast to be pitched?
God I love this hobby! :thumb: :thumb:
cheapbrew
Junk and disorderly
If you have already built up a supply of yeast then experiment,
with my 'house yeast' I use a few tablespoons in 100ml/10g dme to start with if it is reasonably fresh and white looking, if its older and starting to grey after sitting in the fridge awhile then I will use double or triple that amount of yeast, then I next use 500ml/50g dme to step up and I pitch this for 12L for brews up to 1050
with my 'house yeast' I use a few tablespoons in 100ml/10g dme to start with if it is reasonably fresh and white looking, if its older and starting to grey after sitting in the fridge awhile then I will use double or triple that amount of yeast, then I next use 500ml/50g dme to step up and I pitch this for 12L for brews up to 1050
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