An Idea For The Fresh Wort Retailers

[Wortgames]

I don't think we were saying the same thing at all - as I understood it, Dr. Gonzo originally advocated putting the entire contents of the starter mixture (or just the liquid, I'm not sure) into the wort, and believed that this was the reason for using a starter wort similar to the brew. My point is that by all accounts, the starter acts as a venue for the majority of the off-flavour-producing yeast growth to take place, and allows you to discard the off-flavour-containing 'beer' portion, pitching a large and relatively clean slurry into your brew. The reason for matching the composition of starter and brew is not to avoid 'diluting' the brew with the starter, but to allow the yeast to best condition itself to the wort which it will finally face.

I believe Fix when he suggests that starters should really be a lot larger than we homebrewers generally make them, and that is why I said it would be nice to have bottles of AG wort on hand - so that we could build up really large starters, even though most of the liquid will ultimately be discarded.

I don't think anyone is trying to avoid the growth phase altogether in the brew, just keep it to lower levels. I've never measured my slurry, but if you compare the final amount of sediment from a brew with the slurry volume that Fix recommends, I imagine it wouldn't represent more than a doubling or tripling in volume.

Compare it with the amount of slurry your average homebrewer actually pitches though, and you'd probably see an increase in the order of 20 times or more. All of this extra propagation has occurred within the fermenter, and presumably all of the undesirable effects from it are in the beer. It may not be a beer killer, but it may have subtle detrimental effects that could easily be avoided with larger starters.

 

[Malnourished]

The Mr Malty site says a White Labs tube contains 70-120 billion cells of yeast, they recommend adding that directly to a 2L starter which should grow the yeast to 200 billion cells, which is roughly the ideal starter size for 25L of 1.050 ale wort according to the calculator.

So the starter results in a two- to three-fold increase in yeast population, which is on the low end of what you'd experience in a typical healthy fermentation. Obviously people aren't always creating starters from tubes/smack packs, but assuming you stay under the upper limit (according to the BJCP) of three doublings (I assume this means a six-fold, not eight-fold increase in yeast population but could easily be wrong) in your starter production you should be relatively safe. I'm assuming that going near the upper limit is OK because it all ends up getting diluted significantly in the finished beer anyway. You might want to be more careful with lagers and high-gravity ferments though.

So my point is that if the starter is created with a little bit of care, your concern for off flavours caused by yeast growth in starters is (probably) overstated. Then, the only other real concern is that the starter wort and the beer wort are relatively similar.

You certainly aren't going to get any argument from me on the importance of pitching the correct amount of yeast, but I would think that the vast majority of serious homebrewers are already doing this. It's pretty widely recognised as one of the most important factors in beer production.

 

[Wortgames]

OK, then I guess we reach an impasse - Fix reckons that your average slurry will contain 25% viable yeast, and Mr Malty reckons it's nearer 90%.

I'll take Fix's advice over 'Mr Malty's any day




...and I still want to buy unfermented wort in bottles...

 

[Malnourished]

OK, then I guess we reach an impasse - Fix reckons that your average slurry will contain 25% viable yeast, and Mr Malty reckons it's nearer 90%.

I'll take Fix's advice over 'Mr Malty's any day
...and I still want to buy unfermented wort in bottles...

Obviously one of those numbers has to be wrong, even moreso because Mr Malty's primary reference is... you guessed it... Fix! (Take that Noonan!)

Again from Mr Malty:
"There are about 4.5 billion yeast cells in 1 milliliter of yeast solids (solids with no excess liquid). According to Fix, in a slurry, only about 25% of the mass is yeast solids... When the yeast is fresh and healthy off an previous batch, viability is maybe around 90%+. ."

Are you sure this isn't what you're thinking of? Viability and percentage by mass are two very distinct things.

 

[Wortgames]

I wouldn't be surprised if I am getting confused, but I don't think so (then again, how would I know...) :blink:

If you go to Mr Malty's calculator, and on the 'repitching from slurry' tab, hover over the 'non-yeast percentage' slider:

Generally 10% of a slurry is non-yeast material

and in 'An Analysis' Fix makes a meal out of stating:

Uncertainty in the accuracy of volumetric determination of yeast cell counts is related to the uncertainty of the volume fraction of a slurry resulting from yeast solids... Yeast solids are in the creamy middle layer of the sediment and represent 25% of the total volume. In lieu of additional information, we found 25% to be a good working approximation.

That looks like 90% v 25% to me, and as you say, they can't both be right :beer:


Fix asserts thusly:

ideal pitch rate = 1.5 million cells per ml per degree plato (lager)
so for wort of 1048 OG (12 plato) = 1.5 million x 12 = 18 million cells per ml or 18 billion cells per L required.
1ml yeast solids = 4.5 billion yeast cells.
18 billion / 4.5 billion = 4ml yeast solids required per L of wort = 40ml yeast solids per 10L = 80ml yeast solids per 20L
Yeast solids = 25% of slurry, therefore 320ml of slurry required to provide 80ml yeast solids for 20L wort.


That's essentially an entire stubby full of SLURRY for an average home brew batch size, probably more than most homebrewers are pitching.

I tried to follow Mr Malty's maths but he goes into gallons and my brain is decidedly metric. Fancy having a go and seeing if you can find the discrepancy?



And where are my bottles of AG wort *********

 

[Thirsty Boy]

They're BOTH right, they're just talking about different things.

I think this is what each of them is saying and of course I have no doubt I'll be corrected if I am wrong.

DrG - Makes a "starter" from his actual batch. Runs off 5 litres and pitches his yeast into that. When he's ready to pitch his main wort, the whole starter goes in at high krausen? This gives him really active, already working yeast and an amount of cell count increase depending on how long he leaves it. 12-18 hours would give him maximum growth. Less; well, less. Dont know the actual time frame.

Wortgames - is growing a starter in a different wort for the sole purpose of cell count increase. He doesnt want that wort in his actual beer because he thinks it will contain off flavours, so he tips it off. He also could "wake-up his yeast with his actual batch wort and pitch at Krausen if he wanted to, he'd just be starting with more cells and wouldn't have to wait as long for growth. But that part wold be an entirely seperate process to his "starter" and I dont know if he does it or not.

You guys are using the same word to describe two different things. Its the same end - but different processes for gettting there.


The reason there will, or at least should be off flavours in wortgames' propogation spent "beer" is because they should be fermented in a way that would produce those off flavours. Remember, you are growing yeast, not making beer at this stage. So your temperature should be at "yeast loves this" temperature, not good flavour producing temperature. Right when they are prone to producing a lot of off flavours, you should have your yeast at a high enough temperature that they will indeed produce them. You will also, hopefully have heaps of oxygen in that there starter, and for a relatively long time. Some of it is going to go into oxidising the beer before the yeast can grab it, if there isn't enough 02 to do that, then there isn't enough to maximise your yeast growth.

You should also be using a much lower gravity wort than you would use for beer. 1.02 is ideal, but on a homebrew scale to get enough nutrient for yeast growth you would have to make huge starters, so 1.035-1.04 is still ok and far more practical. You chill this down while it is still at growing and before it has started significant alcohol production, then you get it before it decides that it has to ferment a wort of 1.xxx strength and when the time is right, you kick it back into life with the appropriate strength of wort for the beer you want to make - probably some from your actual batch and thats when it aclimatises
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I taste everthing that I use in the brewing process, and the wort poured off the starter after it has been on the stir plate for a day or a few is indeed nasty and full of off flavours. If it isn't, you probably weren't doing your starter in a way that would maximise growth.

Of course DrGs method wont produce off flavours in his starter, why would it. So why wouldn't he pitch the whole thing inot his beer. But I also tend to agree with wort games that he isn't actually doing a lot that wouldn't happen if he just pitched his yeast straight into his main wort, he's more or less just juggling his lag time around and making it happen in a different container. Though I'm sure the process saves time and produces great beer or he wouldn't do it. DrG's method would certainly be a great way to do a starter if you were a no-chill brewer. Although I would still probably want to water down the wort to a low PG.

The real question is - - Is anyone making bad beer? If your beer sucks, maybe try it the way the other guys suggests. If your beer is good, why change??

Of course, I could be wrong. Just my $0.02 worth. Will shut up now. Sorry.

 

[Thirsty Boy]

OK, no I wont... wortgames wrote while I was composing my pompous epic

WG. You seem to be taking the 10% non-yeast solids thing to mean that the left overs are the 90% viable reffered to. Not what MrMalty means.

Its - 10% = non-yeast material
25% = yeast solids
65% = pretty much water

of the 25% that IS yeast solids, 90% of those will be live and viable. So Mr Malty would suggest that you need a little bit more than the 320ml you calculated.

He is however talking about yeast slurry harvested from a fermentor, not grown up from a starter.

 

[Wortgames]

Don't apologise TB, I'm having fun here even if I'm the only one

I totally get what you are saying, although I do take issue a bit with the comment 'is anyone making bad beer' - I don't suggest for a minute that anyone IS making bad beer, but I also don't think this forum begins and ends with 'not making bad beer' - I think most of us are keen to try and make the best beer we possibly can within our means, and if that means splitting some hairs and debating some theory then grab a beer and strap yourself in.

You raise an interesting point though - are the off-flavours produced in a starter purely a result of 'growth-centric' conditions? Fix would apparently say no, as he advocates building starters under conditions that match as closely as possible the final wort, and he still claims that the starter contains off-flavours. He even says that a 'mini-brew', to which more wort is added later, will have these off-flavours. So I'm inclined to think that the off-flavours are created in the propagation phase, however brutally or sedately that is done.

 

[Wortgames]

OK, we're getting all excited and cross-posting now...

In response to #27:

Yep, that looks like it could be the cause for that discrepancy - although I don't really see how slurry from a starter would differ that greatly from slurry from a brew, assuming our starter wort matches our brew wort (I know you don't agree with Fix on that point, but humour me).

Like I said, I haven't really analysed Mr Malty's figures (in fact I hadn't seen the site before today), but something tells me that if you need to pitch x amount of slurry then it shouldn't make a huge amount of difference whether that slurry has come from a beer we drank or one we threw away (ie a starter)?

 

[Malnourished]

Fix asserts thusly:

ideal pitch rate = 1.5 million cells per ml per degree plato (lager)
so for wort of 1048 OG (12 plato) = 1.5 million x 12 = 18 million cells per ml or 18 billion cells per L required.
1ml yeast solids = 4.5 billion yeast cells.
18 billion / 4.5 billion = 4ml yeast solids required per L of wort = 40ml yeast solids per 10L = 80ml yeast solids per 20L
Yeast solids = 25% of slurry, therefore 320ml of slurry required to provide 80ml yeast solids for 20L wort.


That's essentially an entire stubby full of SLURRY for an average home brew batch size, probably more than most homebrewers are pitching.

I tried to follow Mr Malty's maths but he goes into gallons and my brain is decidedly metric. Fancy having a go and seeing if you can find the discrepancy?

Thirsty Boy covered has covered the first part above, though Mr Malty is hardly clear about the whole thing. He does say "Generally 10% of a slurry is non-yeast material. If you can see visible non-yeast material, the amount is closer to 25%." So his and Fix's numbers don't agree entirely, and he doesn't provide a reference for his 10% claim. If you're more of a Fix man you can just set the calculator at 25%.

Using Fix's 25%, Mr Malty's calculator gives between 111mL and 502mL for the same numbers, depending on the thickness of the slurry. Seems to add up to me.

I would agree that it seems unlikely there would be too much difference between yeast slurry from beer fermentation and slurry from a starter, though there is potential for variation if you're crash cooling your starters relatively early.

And I would aim to pitch that much in a lager. Why do something that won't give you the best chance to make good beer?

By the way, if you don't already, try tasting your starters (especially if they're hopped.) When I do I rarely notice any particularly unusual by-products. They usually taste like sweet, yeasty beer. I drank a full glass of recultured Dupont yeast a few days ago. :beer:

What a top thread. No wonder I haven't done any work today.

 

[Dr Gonzo]

I think you pretty much summed it up Thirsty Boy.

One point though!

But I also tend to agree with wort games that he isn't actually doing a lot that wouldn't happen if he just pitched his yeast straight into his main wort, he's more or less just juggling his lag time around and making it happen in a different container.

By this i assume you mean that pitching say a single smackpack into a 50L brew will have the same end result as pitching the same smackpack into a 5L starter and then pitching this into the main brew once at high krausen, and that they would have similar total lag times to coming into krausen.

If so, then i beg to differ. I reckon if you had 2 x 50L brews both the same and pitched a smackpack directly into one of them, and made a 5L starter from the other, pitching another smackpack into that at the same time, then the brew made with the starter would have a more vigorous fermentation come on sooner than the direct pitched brew. The reason being that a smackpacks worth of yeast is going to be overwhelmed by the 50L of wort.

 

[Thirsty Boy]

DrG - My brain tells me that the total time from chill to krausen in the main wort would be the same in both cases....

I guess that any reduction in time to main wort krausen is less because of the volume and the yeasts reaction to it, than because of the speed with which you can get the total process started. Basically, with boiling and cooling in the smaller volume able to be done so much faster, the yeast is simply in wort sooner.

I think that if you pitched yeast into the first 50l at the same time as you pitched yeast into the 5l, and then waited for the 5 litres to hit krausen before joining it with its other 45. Then there really wouldn't be much of a difference. The advantage of the starter is that you wouldn't wait. You'd get the yeast in the starter ASAP and have a chunk of head start.

But I haven't actually done it and you have, and you think faster with the starter. So I'll take it as a given that its true! I actually do a similar thing in my own brews, but i dont even wait for first wort from the chiller, I take some final runnings and a bit from the kettle and boil and cool them seperately. My yeast is being "started" before my main wort even comes to the boil.


Wortgames/Mal - I'm pretty sure that the reason that there would be a difference in the amount of non-yeast in starter slurry than in re-pitched slurry is simply hops and break material. If you make a nice clean starter wort out of nothing but clean and pre-boiled wort its just gonna have less crap in it than stuff you scoop off the bottom of your fermentor. And besides from one of the Fix quotes thats been used already, he is simply using 25% as a useful working figure that will suffice accross the board. Jamil is actually trying to be a little bit more precise with the calculator. But I think that the grey areas in both thier figures leave plenty of room for them to be both saying exactly the same thing in any given situation.

I haven't actually read Fix, but if he does reccommend makning a starter with full strength wort, then he goes against actual professional propogation practice, where they certainly dont. I can't quote Fix, but I can paraphrase the same Palmer quote thats been used before.. . You should make your starter out of wort that is near the same composition as yur main wort, if you are going to be pitching when the starter is at or near peak activity. . . On the previous page to that quote in HTB, he recomends that your starter wort be 1.040. Wyeast recommend that you make your starters at 1.02-03,White Labs recommends approx 1.04 So its seems almost everyone is going for hte lower gravity starter. You only need to have the starter wort match the main wort if you are pitching it at Krausen. Palmer, Daniels, Wyeast and Whitelabs all furthe suggest that you fridge the starter and pour off the spent beer if it was a large (2litre or more) starter.

My spent starter liquid (beer) usually tastes horrible, but I make my starters at abut 25-26 C and there aren't many strains that dont throw some horrible tastes during growth phase at that temp. With more growth in the starter that in the main wort, thats more esters, phenolics etc than you would get out of a full, hot fermentation, all concentrated into a litre or two.... yurk. Of course if you do your starters at fermentation temps, its not nearly such a problem. But its also not optimum for growth.

I like this splitting hairs and nitpicking in search of a better beer, its fun, and I learn stuff. You are right wortgames, why settle for "not bad" beer, or even good beer. Lets have at each other in the quest for Great Beer

Thirsty

 

[Batz]

You guys don't brew great beer?

Very very sad


"Is this the right room for a argument?"


Batz

 

[tangent]

some great points being raised though....

the whole point in stepping up is to keep yeast happy, not stressed.... unless that's what you want.
from what I've heard from discussions from with that yeast bloke on his recent tour of Oz, underpitching was the biggest sin by homebrewers.
If either process works, great!
In these situations of hair-splitting it pays to remember that yeasts behave very differently and lag times and growth can change all sorts of things to different yeasts. Wheaty yeasts are just one iceberg of yeast cell pitching rates. (great blurb by Lyn Kruger (sp?) about phenolic production in wheat beers on BasicBrewing - and she sounds like Tracy Ulman in the Simpsons where Bart tries to train Santa's Little Helper)
Has anyone re-read Zwickels post about all the frozen bags of wort in eery blood sacks in his freezer? Only a German..
That's where I learned the technique. Not Fix or Noonan. To tell the truth I don't think I've heard of them before, so I'd be more likely to take advice from WeeStu, Stoutdrinker or Dr.Gonzo because I've tasted their beers.

 

[Wortgames]

"Is this the right room for a argument?"

I've told you once!


It looks like we've distilled it down to the essential difference of opinion - essentially, how similar should the starter be to the final conditions. Looks like plenty say that the starter should be lower gravity than the wort and optimised to maximise yeast growth, whereas Fix (and Palmer, under certain conditions) vote for one that closely matches it. Perhaps it comes down to your own philosophy.

Personally, I like the idea of matching my starter with the brew. All the work that the yeast are doing is to grow and adapt to a certain environment, it doesn't sit particularly well with me to go for enormous high-speed growth in some kind of steroid-fuelled nursery, then dump the poor bastards into a completely new and somewhat tougher environment, where gravity, hop content, grain bill, temperature and probably even pH are all different.

It may be that it makes absolutely no difference, and that a faster starter with lower OG is simply a more practical way for breweries to build up the numbers quickly - but I'm in no particular hurry and I can't see it actually improving a beer to do it this way.

So for now, my preference will remain to build a large starter with 'real' wort under similar conditions to the brew, tip off the liquid and pitch a large slurry into the brew. I realise plenty don't do it this way but I'm not convinced that any other way will produce better results - I suspect equal at best or more likely, 'undetectably worse'.

And I renew my calls for bottled wort! :beer:

 

[Gulf Brewery]

And I renew my calls for bottled wort! :beer:

Hi Wortgames

An interesting concept. Let's say we do a batch - 1200 litres of 330ml bottles = 3600 bottles. Now divide that between the number of homebrewers that would use it and tell me how long before we could sell it all. We would have to move all of that in under 3 months (preferrably less) to make it worthwhile.

Then there is the pricing - how much would you be prepared to pay for 330ml of wort? By the time we make some money and the homebrew shop makes some money, then you will probably be paying $2 for 330ml of wort.

Cheers
Pedro

 

[Wortgames]

Hi Pedro,

I was thinking more of the small brewers that already package the fresh wort into cubes, and perhaps already have access to small-scale bottling equipment - I agree you wouldn't want to bottle an entire 1200L batch into stubbies, but there might be a market for a few slabs of longnecks (or even PET bottles) from each batch of fresh wort - depending on what can and can't be done of course.

If you are saying it would end up costing $48 for a slab of unfermented wort in 330ml stubbies then obviously there is no milage in it - although that seems a little high given the fact that there is presumably no duty on any of this.

If it can't be done then so be it, and obviously I've learnt from this thread that many brewers DON'T use full gravity wort for their starters anyway, although presumably it would be pretty easy to dilute it to their desired gravity (especially as the fresh wort kits are generally fairly high gravity anyway).

Obviously I'm not in the trade, and I don't know who has got what equipment etc, I was really just hoping to trigger some discussion on the idea.

 

[bigfridge]

If you are saying it would end up costing $48 for a slab of unfermented wort in 330ml stubbies then obviously there is no milage in it - although that seems a little high given the fact that there is presumably no duty on any of this.

No duty - but heaps of labour cost and the hassle of stocking/handling different materials.

They would have to be hand bottled when hot, whereas packagaing lines rely on keeping carbonated beer cold.

It is a good idea though but is uneconomic. Most brewers just use some malt extract, dissolved in warm water and reved up in the microwave.

Dave

 

[Gulf Brewery]

Hi Pedro,

I was thinking more of the small brewers that already package the fresh wort into cubes, and perhaps already have access to small-scale bottling equipment - I agree you wouldn't want to bottle an entire 1200L batch into stubbies, but there might be a market for a few slabs of longnecks (or even PET bottles) from each batch of fresh wort - depending on what can and can't be done of course.

If you are saying it would end up costing $48 for a slab of unfermented wort in 330ml stubbies then obviously there is no milage in it - although that seems a little high given the fact that there is presumably no duty on any of this.

Hi Wortgames

Look at this way - commercial boutique breweries sell beer for $50 to 60 ($2.25 to $2.50 per bottle) in packs of 24. It is less than 40 cents excise per bottle (quick and dirty calc). So apart from the yeast / fermentation costs being taken off from the carton cost (it has to bottled really cold), you are still looking at a high price product for such a low volume. Bottling is an expensive (labour and capital) exercise, so unless it is a really high volume product, then it really isn't viable.

Now, would everyone buy 330ml bottles of wort in packs of 24? If you break packs it increases the costs yet again.

Like bigfridge says "It is a good idea though but is uneconomic"

Cheers
Pedro

 

[Wortgames]

OK, point taken, although I wish you'd drop this idea of selling it by the 330ml stubby - I certainly never suggested that. I was only ever thinking in terms of cartons of longnecks (which the retailer may or may not choose to split) or PET bottles, or even 5L containers. In fact, just about anything that would lend itself to being used in smaller quantities than the 17L cubes it currently comes in.

Like I said in my original post, we could bottle the wort ourselves into longnecks, but I'd be concerned about sanitation and to do it safely would presumably require pressure cooking - which could be avoided if it were packaged that way at source instead.

How much more would it cost to package into 5L packs rather than the current cubes? Exactly where does this sudden leap in costs occur?