222 replies to this topic

[positiveContact]

I don't think it's as violent as a stir bar.  The whole thing came up discussions of how yeast companies use shaker tables rather than stir plates for propagation.

 

well shaking it like it owes  you money sounds very violent.  certainly it would be moving the liquid at a much higher rate with higher accelerations and decelerations.  F = ma.

 

eta:  nm, I see the shaking is done prior to adding yeast.

 

eta:  nm the nm, the instructions see have adding the yeast before the shaking part.

Edited by Evil_Morty, 28 September 2015 - 09:58 AM.

[Brauer]

so why wouldn't shaking also damage the yeast cells? shaking seems more violent than a stir plate.

The shear forces are different. I've developed bioreactors for other eukaryotic cells and shakers deliver higher cell counts and viability than stirbars. There are other stirring mechanisms that work well, but they keep the bar off the bottom, so the problem may be more about grinding. To get equivalent growth to a stirred reactor, though, you need continuous shaking. A periodic shaking will probably only get you about 60% of the growth of a stirred starter, from the numbers I've seen.

[Brauer]

well shaking it like it owes you money sounds very violent. certainly it would be moving the liquid at a much higher rate with higher accelerations and decelerations. F = ma.

eta: nm, I see the shaking is done prior to adding yeast.

eta: nm the nm, the instructions see have adding the yeast before the shaking part.

Shaking is probably the wrong word, though that's the one we use, in the field. It's more like vigorous swirling.

[positiveContact]

Shaking is probably the wrong word, though that's the one we use, in the field. It's more like vigorous swirling.

 

that may be true but I'm going by what this particular person is advocating which seems to be violent shaking to make the whole thing foam up as much as possible.

[Brauer]

that may be true but I'm going by what this particular person is advocating which seems to be violent shaking to make the whole thing foam up as much as possible.

Yeast are small, so they are a bit resistant to it, but foaming is usually considered undesirable because it has it's own shear force and it denatured proteins.

[positiveContact]

Yeast are small, so they are a bit resistant to it, but foaming is usually considered undesirable because it has it's own shear force and it denatured proteins.

 

so you seem well versed in this stuff, what do you recommend for the average home brewer?

[SchwanzBrewer]

so you seem well versed in this stuff, what do you recommend for the average home brewer?

 

The easiest method for you.

 

Here's the problem I see with this - practicality. I really doubt you'll see any improvement via a blind taste test between a shaken and stirred starter when the proper yeast count is pitched. Second, many people make larger batches than 5 gallons so having a 4X larger container is troublesome when you need to make a starter even jumping to a 2L starter let alone guys like me that need a starter for 1bbl.

 

Unfortunately, though I'd love to do some experiments, I don't have the set up to do it anymore. 

[denny]

The easiest method for you.

 

Here's the problem I see with this - practicality. I really doubt you'll see any improvement via a blind taste test between a shaken and stirred starter when the proper yeast count is pitched. Second, many people make larger batches than 5 gallons so having a 4X larger container is troublesome when you need to make a starter even jumping to a 2L starter let alone guys like me that need a starter for 1bbl.

 

Unfortunately, though I'd love to do some experiments, I don't have the set up to do it anymore. 

 

As far as I can tell, the shaken starter is more about yeast health than cell count.  The contention is that in a stirred starter you're doing enough damage that the increased cell count doesn't overcome the poor yeast health.

[positiveContact]

As far as I can tell, the shaken starter is more about yeast health than cell count.  The contention is that in a stirred starter you're doing enough damage that the increased cell count doesn't overcome the poor yeast health.

 

so how exactly did you handle your starter for this experiment?  how hard did you shake the starter and how often?

[SchwanzBrewer]

As far as I can tell, the shaken starter is more about yeast health than cell count.  The contention is that in a stirred starter you're doing enough damage that the increased cell count doesn't overcome the poor yeast health.

 

Man, that's a tough sell for me, especially if you are pitching a stirred starter at high krausen.

 

Can you tell yeast health just by looking through a microscope? I guess if it's poor, you'll see less active and more dead cells on your slide?

[denny]

so how exactly did you handle your starter for this experiment?  how hard did you shake the starter and how often?

 

I shook occasionally throughout the incubation.  I shook fairly hard but not as hard as Mark advocates.  This thread is continuing to evolve over on the AHa forum.  I'd suggest you go read it so I don't misinterpret something.

Man, that's a tough sell for me, especially if you are pitching a stirred starter at high krausen.

 

Can you tell yeast health just by looking through a microscope? I guess if it's poor, you'll see less active and more dead cells on your slide?

 

You have to get rid of your preconceived ideas...it's tough, believe me!  Please, do yourself a favor and follow the discussion on the AHA forum so I din't give you bad info.

[denny]

New thread with more info....httpss://www.homebrewersassociation.org/forum/index.php?topic=24460.0

 

Keep in mind, that I was (and remain) pretty much as skeptical as you guys.  But I decided that rather than say "that can't work" I'd find out for myself.

[positiveContact]

thanks for the experiment denny.  I should probably just join up over there.

[positiveContact]

I have to tell you that the use of the word "simplified" is ironic here since all this has done is brought into question everything that I thought was a best practice

[SchwanzBrewer]

I shook occasionally throughout the incubation.  I shook fairly hard but not as hard as Mark advocates.  This thread is continuing to evolve over on the AHa forum.  I'd suggest you go read it so I don't misinterpret something.

 

You have to get rid of your preconceived ideas...it's tough, believe me!  Please, do yourself a favor and follow the discussion on the AHA forum so I din't give you bad info.

 

I'm not saddled with preconceived notions! I'm thinking logically and practically is all. If the proof is in the pudding so to speak then it will come out and ye verily the beer will be good.

[denny]

thanks for the experiment denny.  I should probably just join up over there.

 

Yeah, you should.  This forum has some great people with a lot of info, but there are a lot more over there.

I have to tell you that the use of the word "simplified" is ironic here since all this has done is brought into question everything that I thought was a best practice

 

That's how progress is made, man!

I'm not saddled with preconceived notions! I'm thinking logically and practically is all. If the proof is in the pudding so to speak then it will come out and ye verily the beer will be good.

 

Yeah, but what if the framework for your logic and practically is incorrect?

[neddles]

Yeah, you should. This forum has some great people with a lot of info, but there are a lot more over there.

Add to it that the beer forum isnt supported by the vast majority who traffic this site.

[SchwanzBrewer]

But, you'll have to have a triangle test to really give a difference. That's where I'm most skeptical. 

[SchwanzBrewer]

 

Yeah, but what if the framework for your logic and practically is incorrect?

 

You're making assumptions about me here that are just false. I'm more than happy to accept changes that are positively identified as accurate and best practice IF they are practical in application for me. Someone here taught me that...

[denny]

But, you'll have to have a triangle test to really give a difference. That's where I'm most skeptical. 

 

Agreed, but as I said this trial isn't about that.  That's why I used a beer that I've brewed many times over the last 15 years and know well.  But I assure you a split batch, triangle test with cell counting is in the planning.  I also hope to have a microbiologist do an assessment of yeast health.

You're making assumptions about me here that are just false. I'm more than happy to accept changes that are positively identified as accurate and best practice IF they are practical in application for me. Someone here taught me that...

 

Okey dokey!