Shaken, not Strirred

[Aleman]

One benefit of the Braumeister that I didn't foresee was making starters became so much easier.

Aleman, can you explain this further?

Simple, my usual batch length was 95Litres meaning that I needed around 950 Billion (Ales) to 1800 Billion (Lagers) cells to pitch, this meant excessive sized starters and step ups from a fresh whitelabs tube. The Braumeister is 20-23L meaning only 200 to 400 Billion cells are required, which is very easy to achieve . . . unless like me you let your tubes sit in the fridge for 12 months

[barry44]

I see!!

[Haydnexport]

ive done the shake method on a 1l starter in a 5l plastic bottle , it was so vigerous after 2 days , (id forgotten to put an airlock lid on) it blew the lid clean off and almost gave me a heart attack. Ive never done the stir plate , and doubt now i ever will seeing how easy and effective this is.

[lizzard]

Thankyou for sharing your knowledge,
But could you please explain why we could not achieve the same results by doing the following...
On the pre inoculated cooled wort on a stirplate , rapidly spin the stirbar in the conical for 30 minutes..
Then pitch the yeast into the conical at low rpm (<30)
Do you think this would change the outcome, and why.

[Jocky]

The reasoning behind this method is that the vigorous shaking rapidly saturates the starter with air.

The theory behind a stir place is just that it keeps the starter moving enough for continual gas exchange, so I don't think it would achieve anything like the level of saturation in 30 minutes.

In theory once the yeast is in the starter you really just want a brief gentle stir to distribute it, anything more violent may damage the health of the yeast, and the whole point of this method is to avoid the shear stress of continual stirring on a stir plate.

I'm not saying that your method won't work - the point is that the method described in this thread is a low tech way of getting a great starter, and avoids using a stir plate for stated reasons.

[lizzard]

Thanks for the explanation Jocky.
I was trying to ascertain if the foam creation was to assist the yeast any more than any 21% O2 wort solution. (from air stone , shaking or tornado speed stir bar)
Although Kais work has shown non empirically that stir plate speed could increase cell count http://www.braukaiser.com/documents/Tro ... tarter.pdf

I see many others that work with yeast talk about shear. (stir plate speeds too high)
So im very interest in this method.

Although I think with our existing HB setup with conical stir bar and foil we can whip up a tornado and saturate the wort with air quite well in a 30 minute period. (although I have non reference for this)
Then add your smack pack / vial / pack.
Turn stir bar speed down to really slow, or off completely
wait for High K
Pitch
Done

Maybe im just being lazy with the shake. Maybe I cant see the advantage.

[Jocky]

By 21% O2 wort solution do you mean 21ppm of O2? I don't think you can get above 9ppm of O2 by shaking. Anyway, here's a 1.5 litre starter moments after I stopped shaking (2 mins of shaking) and pitched the yeast:

download/file.php?id=1744&t=1

[lizzard]

Hi Jocky
To clarify, by 21% 02 I mean the same pp as air, 159mmhg
Basically, no O2 stone.

Shaking with the yeasties sure whips it up.

So. Any faults or problems anticipated with the method of pre aeration with stir bar vortex?

[lizzard]

Oh, and I see no one has mentioned the omission of nutrient in the method.

[Aleman]

Oh, and I see no one has mentioned the omission of nutrient in the method.

Could that be because Wort has more than enough nutrients anyway? . . . The only time you might want to add something is if for some reason you believe that your wort is deficient in FAN (Free Amino Nitrogen) or possibly zinc (That is required in the microgram quantities in a 25L batch so adding it to a 1L starter is overkill).

Nutrients (FAN) are required in a wine must as they tend to be deficient in FAN)

The same applies to mead as that is really just a sugar solution.

[lizzard]

[quote="Aleman"][quote="lizzard"]Oh, and I see no one has mentioned the omission of nutrient in the method.[/quote]
Could that be because Wort has more than enough nutrients anyway? . . . The only time you might want to add something is if for some reason you believe that your wort is deficient in FAN (Free Amino Nitrogen) or possibly zinc (That is required in the microgram quantities in a 25L batch so adding it to a 1L starter is overkill).

Nutrients (FAN) are required in a wine must as they tend to be deficient in FAN)

The same applies to mead as that is really just a sugar solution.[/quote]


Thanks for clarifying that Aleman

[dunwood0191]

The other ingredient of methylated spirits is pyridine, which gives it the foul smell.

[YeastWhisperer]

Man, I cannot believe that this thread is still alive, but I am glad that the topic is still being discussed and debated.

As to Lizzard's questions, the method takes advantage of the fact that a gas-foam has a very high specific surface area. Foam is basically extremely thin layers of liquid surround by gas. A gas dissolves into a liquid at the interface between the gas and the liquid based on the partial pressure of the gas. The higher the amount of surface area, the more rapidly O2 is dissolved.

One area that is still in question is, do the yeast cells that are in the bubbles take in O2 directly from air like they do when grown on the surface of solid media? As you mentioned, we are talking about 21 parts per hundred O2 versus 8 parts per million O2. I believe that they do take in O2 directly from air while suspended in foam. The thickness of a wort bubble has to be on the order of a the thickness of a soap bubble. Soap bubbles are usually anywhere from 10 nanometers to over 1000 nanometers in thickness. Saccharomyces cells are anywhere from 5 to 10 micrometers in diameter. That difference has to mean that at least some cells are directly exposed to air.

[lizzard]

Interesting.
Although I do retract my previous comments about stir bars creating foam pre pitch. No where near the same aeration in my tests.
Although I am still concerned about shear with shaking (especially with my particular choice of bottle) .
So I shake my 5l ribbed plastic bottle before pitching my vial.
YES! Those ribbed plastic bottles generate foam much quicker!!
Then pitch the vial and give a smaller shake to suspend, without shearing too much.
Nice results!
However I was already aerating starters and ditching my O2 stone after reading these threads not so long ago anyhow.

http://thebrewingnetwork.com/forum/viewtopic.php?t=4000

http://brulosophy.com/2015/06/29/yeast- ... t-results/
(4th paragraph down)

But shaking is easier than air stone in starters hygine wise, so nice one yeastwisperer / s cerevisiae !

[vacant]

I've stepped up Proper Job yeast on quite a few occasions, finishing off on a stir plate. "Takes of like a rocket" often applies when pitched. This time I tried:

• Wednesday, pour two bottles of PJ
• Swill yeast from bottom with 50ml 1.030 wort
• Dump into Colman's mustard jar and shake to a froth
• Thursday, dump into a litre of wort in a demijohn, shake to a froth

Saturday afternoon I poured the starter into 20 litre of wort. Sunday all looked good - a nice krausen a couple of centimetres deep, Monday morning it had overflowed a 33 litre FV. Oops! Should have guessed it might do that, luckily the FV was on a large plastic sheet.

Thanks for the method - very easy, I'll be doing that again.