Help!! Why does my starter look like this

[Beer_Guy]

After a lot of thought on the matter, I agree that foil is better.

Here is why...

Since Co2 is heavier it will be pushed by centrifugal force to the outside of the spinning air inside the vessel. Since the airlock exit is usually dead center, any positive pressure will cause the air in the center (O2) to exit first.

Here is another thought…
Since you want to evacuate as little of the O2 as possible, a large mouth round container would be better. This would cause the beginning Co2 to be pushed out of the gaps in the foil cover at the edges sooner than with a tapered small mouth container. The taper will cause the spinning Co2 to collect at the widest part until it builds up enough to reach the lip at the top.

Ok, maybe I am over thinking it. But hey, I just want to understand it. That is what is fun about this hobby for me.

ClaudiusB; I noticed you’re aerating 24/7 for the growth stage. Looks like you get excellent results. I like it.

 

[nealperkins]

You can answer many of these questions by going to MrMalty.com
(http://www.mrmalty.com/calc/calc.html) and progressively selecting the different ways in which to treat your starter. There is a dramatic difference upon your final growth rate.

A very experienced friend of mine told me about this and let me tell you that if you do the following, you are going to make sure you do NOT FORGET the foam control or that yeast is gonna crawl right out of that flask! (ask me how I know...) And, should you step up a starter for a second round, jump back!

Anyway, put the starter on a stir-plate and and insert the tube from an aquarium pump (with in-line sterile filter). The tube does not have to be immersed in the wort (used to do this but there is no diff in leaving it above the wort).

Now your concern might be that you can easily generate too much yeast. My friend was right!

 

[TipsyDragon]

Except, then what do you do to seal off the starter so it does not get infected?

a sanitized piece of aluminum foil. bacteria don't move up and the airborne ones cant get around the foil.

 

[rayg]

1. Entire batches of beer are made in
big open fermenters, but those beers
are made with huge slurries of active
yeast. An airlock is a wise precaution
when you are not pitching directly
on a yeast cake because of the lag,
which will allow wild yeast to float
down into your beer on dust and begin
to reproduce.

2. This business about O2 uptake is
really off the mark. O2 is taken up
by the yeast before CO2 is produced,
it is a necessary food, but once the
CO2 is produce, ALL of the O2 is blown
out of solution and none gets in, airlock,
stirring, or no. The only thing stirring
is useful for is preventing blowoffs,
because it breaks up the gas bubbles
faster. If you are scaling up your yeast,
you need to wait for CO2 to subside,
then aerate the fresh wort. Aeration
during fermentation is useless.

As far as the op's concern about the
appearance of the yeast: they come in
many different shapes and even the same
yeast can flocculate in a million different
shapes depending on the concentration
of the wort, Ca content and a million other
things. Unless it smells bad, I wouldn't
worry about it.

 

[Yooper]

2. This business about O2 uptake is
really off the mark. O2 is taken up
by the yeast before CO2 is produced,
it is a necessary food, but once the
CO2 is produce, ALL of the O2 is blown
out of solution and none gets in, airlock,
stirring, or no. The only thing stirring
is useful for is preventing blowoffs,
because it breaks up the gas bubbles
faster. If you are scaling up your yeast,
you need to wait for CO2 to subside,
then aerate the fresh wort. Aeration
during fermentation is useless.

I have to disagree with #2, at this part: "The only thing stirring
is useful for is preventing blowoffs, because it breaks up the gas bubbles
faster."

That's incorrect. A stir plate is useful to keep the yeast in suspension. Not for preventing blowoffs. There is indeed some gas exchange, but the main reason to use a stirplate is to keep the yeast in suspension.

 

[Brew-boy]

I take it you ferment in a carboy then? It seems it would be a pita to try to cover a bucket, unless those really long boxes of reynolds heavy duty are wide enough.

When I do use a carboy that is my method. I go back and forth between the conical and the jug.

 

[sysera]

I don't know if it was mentioned or not, but I also think the back pressure an airlock will apply to that relatively small volume of starter (wort) will probably cause a slight increase of stress on the yeast, and I'm assuming that's not the best thing for creating a clean yeast.

 

[maztec]

So, looking at the link provided to Mr. Malty's Pitching Rate Calculator, I note that I do the "periodic aeration/shaking" method. Which means, all things considered, I'm fairly close to the continuous aeration and stir plate methods - as opposed to the "simple starter" or "simple starter with o2 at start" methods.

So, unless I'm doing a 10 gallon batch, where the difference in starter volume is almost half a gallon, I don't see a lot of point in taking that next step in cost and time...

Eh?

 

[rayg]

I have to disagree with #2, at this part: "The only thing stirring
is useful for is preventing blowoffs, because it breaks up the gas bubbles
faster."

That's incorrect. A stir plate is useful to keep the yeast in suspension. Not for preventing blowoffs. There is indeed some gas exchange, but the main reason to use a stirplate is to keep the yeast in suspension.

But what does keeping it in suspension do?
How do you keep it in suspension in your
5 gal carboy? Answer: The CO2 produced keeps
it in suspension until it flocculates.

The problem with all this stuff is that
it's adapted from the practice of large
scale brewing. For example, large fermentation
vessels are jacketed to control temp, because
it's the only effective way to control the
temperature exactly with such large bulk.
But that's not necessary with 5 gal carboys.
Likewise, if you are growing yeast on a
ton scale, the yeast cake is going to be
huge and the bottom of the cake is not
going to be exposed to the wort, so you
stir it to get a few percent more yeast
cells.

The oxygenation part of this is what kills me.
If you make a fermenter out of a long thin
tube, put holes in the bottom to blow air
through, then the air bubbles will be in
contact with the liquid for a relatively
long time because of the length of the tube.
If you do this, AND stir it rapidly, you
will get better yeast growth. But using
a mag stir bar to stir yeast in an erlenmayer
isn't going to do anything for your
oxygenation because the CO2 produced prevents
any O2 from getting in. The best you can
do is aerate well before the fermentation
begins (the stirrer will do that, but you
don't need to use it, you can just shake it)
and aerate any fresh wort that you add if
you are propagating again.

The op was making a Kolsch. Does that
require some super-precise amount of yeast
to worry about? I've made made starters in a
quart bottle, with the only aeration some
shaking at the beginning, they always come
out fine.

Ray

 

[Beezer94]

Please do not word wrap on your own it's impossible to read

The stir-plate keeps the yeast and sugars and nutrients in full contact for maximum reproduction in faster periods of time.

You do not stir-plate the beer because we do not like the taste of wet cardboard.

 

[maztec]

Mmmm.... wet cardboard *drool*.

The self word wrapping was a touch obnoxious, but I wouldn't go so far as to say it was impossible to read.

And, from what I can tell, Beezer & rayg just agreed that the purpose is to maximize yeast, sugar, nutrient contact. Which leaves the "does it add more oxygen" or not argument.

Anyone want to test this? Here you go - measure up some dissolved oxygen: http://www.ecy.wa.gov/programs/wq/plants/management/joysmanual/4oxygen.html

 

[Beer_Guy]

… Which leaves the "does it add more oxygen" or not argument.

Anyone want to test this? …

Simple test…

Put some clear water on a stir plate and watch it, you will see there are a lot of small bubbles coming off the end of the vortex cone. As long as oxygen is in the air above the vortex it is being added to the starter wort.

Once all the nutrients are used up, it is done and needs no more oxygen. That is when we might begin to get cardboard flavors. Best way to get the desired yeast growth is to insure more than enough nutrients are in the starter wort to begin with.

 

[rayg]

Simple test…

Put some clear water on a stir plate and watch it, you will see there are a lot of small bubbles coming off the end of the vortex cone. As long as oxygen is in the air above the vortex it is being added to the starter wort.

If you can see the bubbles, then they are not being absorbed.
The bubble would have to pass through a long length of liquid
to make any significant impact. But in any case, once the
fermentation begins, there is only CO2 directly above the liquid,
so it's pretty much useless for getting O2 in the beer.

Those interested should check out the mp3
file here:
http://www.basicbrewing.com/index.php?page=radio
May 13, 2010 - Stir Plates and Triangle Tests

It appears aquarium bubblers work significantly
better than stir plates. The other part of the show
discusses a taste test of an underpitched beer
versus recommended pitch rate beer.

Ray

 

[rayg]

Mmmm.... wet cardboard *drool*.

The self word wrapping was a touch obnoxious, but I wouldn't go so far as to say it was impossible to read.

And, from what I can tell, Beezer & rayg just agreed that the purpose is to maximize yeast, sugar, nutrient contact. Which leaves the "does it add more oxygen" or not argument.

Anyone want to test this? Here you go - measure up some dissolved oxygen: http://www.ecy.wa.gov/programs/wq/plants/management/joysmanual/4oxygen.html

I don't think the extra contact makes a significant difference on the small
scale that homebrewers work. Given that an underpitch of 40% of the
normal doesn't make a huge difference, I doubt that the stir plate pays
for itself.

The word wrapping is because if I don't, I often get alternating short and
long lines, which is a lot worse to read.

Ray

 

[maztec]

Simple test…

Put some clear water on a stir plate and watch it, you will see there are a lot of small bubbles coming off the end of the vortex cone. As long as oxygen is in the air above the vortex it is being added to the starter wort.

Once all the nutrients are used up, it is done and needs no more oxygen. That is when we might begin to get cardboard flavors. Best way to get the desired yeast growth is to insure more than enough nutrients are in the starter wort to begin with.

Seeing the bubbles does not guarantee they are going in or going out. Furthermore, it does not guarantee they are O2, CO2, Nitrogen, or something else entirely.


Visual tests for things like this just are not enough. You would have to measure the actual level of oxygen within the fluid. Then, you still have to account for how much oxygen is getting in or out. Someone suggested diffusion, but that only works across a permeable barrier. In this case we have a raised, solid barrier which may or may not be covered. Thus, if there is something heavier than oxygen within it, we are not going to see the oxygen diffuse into the vessel. Instead, it will sit on top.

Now, there is some theory to the idea that spinning the liquid will cause fluid air above to match its rotation and cause an exchange within the flask. However, this defeats the entire purpose of an Erlenmyer flask, which is to maintain the integrity of the ingredients within it - which an exchange of oxygen would disturb. Furthermore, while some amount of air may get stirred and exchange the bulk of it will reach a point of stasis - unless you create turbulence by stopping and starting the stir plate. Thus, I just do not see much exchange of gasses going on here.

I think the additional attenuation you are seeing - which is roughly 10% as opposed to 100% for standstill versus shaken - is more to do with the suspension of the yeast and nutrients than to do with any hypothetical exchange of gasses.

You want to test this, you need to put several batches side by side, from the same mother, and test them simultaneously:

1) straight from the mother, uncapped, let it sit; (control)
2) straight from the mother, capped, let it sit;
3) straight from the mother, stirred, uncapped, let it stir;
4) straight from the mother, stirred, capped, let it stir;
5) shaken to aerate, uncapped, let it sit;
6) shaken to aerate, capped, let it sit;
7) shaken to aerate, uncapped, shake periodically;
8) shaken to aerate, capped, shake periodically;
9) shaken to aerate, stirred, uncapped, let it stir;
10) shaken to aerate, stirred, capped, let it stir;
11) bubbled to aerate, stirred, uncapped, let it stir;
12) bubbled to aerate, stirred, capped, let it stir;
13) bubbled to aerate, stirred, keep bubbling, uncapped, let it stir;
14) bubbled to aerate, stirred, keep bubbling, capped, let it stir.

And you could probably do a few more variations from there. Keep them all at the same temperature, same lighting, same area. Then at 12 hours, 24 hours, 36 hours, 48 hours, 72 hours take a pipette and measure the amount of O2 within them and the amount of CO2 inside the neck of the bottle; also measure the level of yeast at those times by taking a long pipette to the bottom, drawing it, and placing it in a secondary vessel for measurement (fridge, let it settle, measure).

Alternatively, know enough biology, physics, and chemistry to calculate all of this without having to do the actual testing.

 

[Yooper]

Please do not word wrap on your own it's impossible to read

The stir-plate keeps the yeast and sugars and nutrients in full contact for maximum reproduction in faster periods of time.

You do not stir-plate the beer because we do not like the taste of wet cardboard.

This. You don't oxygenate your beer, as it oxidizes the beer and ruins the taste.

The stirplate is used to keep the yeast in suspension. A quart bottle works. It works better if you jiggle it when you walk by. It works best if you have it on a stir plate.

You always want to pitch the optimum amount of yeast for your batch, whether it's 1 gallon or 100 gallons. Pitching the proper amount of yeast at the proper temperature makes the best beer. You CAN underpitch, overpitch, ferment too hot, ferment too cool, etc, and make beer. You can make better beer if you pay attention to pitching rate and temperature.

From Wyeast's website: http://www.wyeastlab.com/hb_pitchrates.cfm

It's all good info, but I'll just post two sentences here: Consistent and reproducible fermentations are not possible without consistent and adequate pitch rates. Quantity of yeast added to the fermentor will affect every aspect of your finished product, from attenuation level, to flavor and aroma profile, to clarification.

Also, from that same website regarding stirplates:

Stirring and O2:
Agitation aids in removing inhibitive CO2 from suspension as well as possibly adding small amounts of oxygen. Stirring or shaking the starter periodically or using a stir plate will improve cell growth. The use of stir plates has been shown to increase cell growth 25-50% over a non-stirred starter.
Small additions of oxygen periodically throughout the growth of a starter will replenish sterols and improve cell yield

(Now this brings up the same beginning idea- don't use airlocks on your starter, because you want to get the co2 out easily. Co2 actually inhibits yeast reproduction).

 

[Beer_Guy]

Maxtec;
I would go with #14.

From what Yooperbrew posted the stirring will help remove any Co2 from the wort as it is produced. Using an aerator to continually add oxygen to the wort on the stir plate gives the yeast plenty of oxygen to grow.

So, it would seem that a stir plate with an oxygen feed might produce more healthy yeast quicker. Thus #14 by sheer logic.

 

[maztec]

Beer_Guy: I would agree with that. However, the suggestions of just using a stir plate without active aeration only add suspension, not oxygen. Or if they do add any oxygen it is a negligible amount that is unlikely to produce any significant effect.

I have read two sets of suggestions for pitching rate in 5 gallon batches. One, as sponsored by Wyeast, is that one liquid smack pack is perfect for ales under 1.060 OG. The other is that you should use more than in the smack pack by growing a starter, because the liquid smack packs are a bit on the low side and often under-produce due to age of the smack pack.

Speaking of smack packs ... The one I received last week was apparently pre-smacked before shipping, and I didn't have time to use it immediately. Meh.

 

[Beer_Guy]

Beer_Guy: I would agree with that. However, the suggestions of just using a stir plate without active aeration only add suspension, not oxygen. Or if they do add any oxygen it is a negligible amount that is unlikely to produce any significant effect.
…

Probably not much as you said, but SOME. The positive effect from using foil instead of an airlock testifies that it does help.

… I have read two sets of suggestions for pitching rate in 5 gallon batches. One, as sponsored by Wyeast, is that one liquid smack pack is perfect for ales under 1.060 OG. The other is that you should use more than in the smack pack by growing a starter, because the liquid smack packs are a bit on the low side and often under-produce due to age of the smack pack.
…

I noticed that too. I think I will go with MrMalty’s rate and make a starter. My current brews are 1.052 and a set rate for ANY brews under 1.060 is not good enough for me.

…
Speaking of smack packs ... The one I received last week was apparently pre-smacked before shipping, and I didn't have time to use it immediately. Meh.

If it was kept cold during shipment, the yeast should be alive, just grown. I hope you tried it before dumping it.

 

[kegtoe]

i think the condition with my starter must just have been the yeast type. I pitched it yesterday and wild fermenting this morning.

 

[sdp07d]

Foil is safe since the nastys cannot crawl up so it doesn't hurt to use it unless you have flys around the house. Also, from my experience, when I make yeast with a stir plate and an airlock the beer tastes decent. When I use foil, it tastes like cardboard. From what I understand cardboard is an oxygenated flavor, so it seems that it must be oxygenated more with foil?

Also, the link below tells a lot about yeast propagation.

http://www.maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices

 

[kegtoe]

wow , this post turned into something other than what it was intended. I didnt mean to insult poeple when questioning wether to use an air lock. Using foil at that time was never mentioned by the folks replying to my message until after i questioned not using an air lock. I agree with a few of you about the fact that there is little difference between the air lock and foil. The yeast need oxygen soon after pitching. after some time the amount of O2 is really negligible as the yeast go on to do other things.

Wether you use an air lock or foil you are starting with the same amount of air in the vessel. I agree that less will likely escape with the foil once fermentation begins, but by that point the yeast need for O2 is minimal. I shake my starter vigorously for the first several hours to make sure there is O2 in solution and the yeast are well seperated.

 

[Mikesterbrau]

Back to the original poster's question (If I may at this point ):

I have a Kolsch in its lagering period right now that I made with WLP029. My starter looked almost exactly the same as the op's, and after a couple of days in the fridge the yeast settled to a nice layer of yeast-concrete at the bottom of the flask. It was actually a little bit of a chore to get it out, which was surprising given what I'd read about Kolsch yeast generally being less flocculent.

I've heard from other sources that White Labs' Kolsch strain is just like that. Very different behavior than the Wyeast Kolsch strain.

 

[kegtoe]

perfect, thanks mike