Shaken, not Strirred

[McMullan]

I wouldn't say an orbital shaker is much like the shaken-not-stirred method. Entirely different. I distinguish between them and plan to assess both in my experiment. An orbital shaker, the method of choice in a culture laboratory, applies a continuous swirling motion without foam production. If anything, an orbital shaker is more comparable to a stir plate set at very low speed, although they differ, in terms of a stir plate usually having a vortex.

Thinking about the BrewLabs 'trial', what was its purpose? A trial without any control? What are the results being compared with?

[lizzard]

Wyeast and White Labs ship yeast cells that are in a state known as quiesence. A Wyeast smack pack has the advantage of being able to wake the cells up via smacking and allowing the package to swell before pitching. That being said, one can treat both manufacturer's products as interchangeable when making a shaken, not stirred starter.

Ok. Tx

[Goulders]

The Brewlabs trial had a video showing how to prepare the yeast. It wasn't the vigorous shaken method here that was recommended. More a gentle shake. The purpose was to analyse beers all prepared in the same way with a variety of yeasts. Everyone's water will be different and samples of liquor before and after treatment, pre-fermented wort, and bottled samples were taken. Also the gravity/temperature were recorded every 24 hours and the volume of yeast pitched. In my view, yeast grown from a fresh slant will be more viable than something flown in from America. Further, in the experiment the yeast was grown over 48 hours and the denatured wort decanted off before pitching.

[McMullan]

The Brewlabs trial had a video showing how to prepare the yeast. It wasn't the vigorous shaken method here that was recommended. More a gentle shake. The purpose was to analyse beers all prepared in the same way with a variety of yeasts. Everyone's water will be different and samples of liquor before and after treatment, pre-fermented wort, and bottled samples were taken. Also the gravity/temperature were recorded every 24 hours and the volume of yeast pitched. In my view, yeast grown from a fresh slant will be more viable than something flown in from America. Further, in the experiment the yeast was grown over 48 hours and the denatured wort decanted off before pitching.

Got it, an assessment of their yeast slopes in the hands of grubby home Brewers. Nice of them to do that, actually. Shows they care about their product and their customers. It'll be interesting to see if they change their recommended protocol. I've noticed the relative superiority of slopes too. Interesting why that might be and strange White Labs and Wyeast don’t offer yeast slopes.

[orlando]

strange White Labs and Wyeast don’t offer yeast slopes.

You can't charge £6/7 for a slant.

[rpt]

You can't charge £6/7 for a slant.

Brewlabs do.

[YeastWhisperer]

I wouldn't say an orbital shaker is much like the shaken-not-stirred method. Entirely different. I distinguish between them and plan to assess both in my experiment. An orbital shaker, the method of choice in a culture laboratory, applies a continuous swirling motion without foam production.

Your assertion is correct. My method is a radical take on basic shaking. Stumbling upon it was purely a case of serendipity. However, I would say that my method is closer to an orbital shaker in action than a stir plate. An orbital shaker is capable of producing foam without exposing the cells to impeller shear stress. If a stir plate was even remotely close to an orbital shaker in action, labs would use use stir plates instead of orbital shakers. A used small orbital shaker is still significantly more expensive than a stir plate.

[YeastWhisperer]

I grow almost every culture that I use in brewing from slant, so I am torn between agreeing and disagreeing on whether or not slants are superior to liquid cultures. One advantage that a slant has over a liquid culture is that the cells on a slant where grown in the presence of 21 parts per hundred oxygen, which makes a difference in sterol and UFA reserves. On the other hand, slants get old too.

A lot of the difference in performance that you are experiencing in the UK is due to age and handling. Liquid cultures from the big two liquid culture producers here in the United States have to travel almost 9,000 kilometers while being exposed to all kinds of stresses to reach the UK. I had to re-plate every Brewlabs slant that I received. Having to re-plate the cultures should be construed as an indictment of Brewlabs' quality. It was an acknowledgement that the yeast cells experienced a lot of stress during their journey. For example, my Somerset culture was so stressed that it threw a metric truckload of ethyl heptanoate. I am a big fan of that ester, and it was too much for me. One of my children remarked that the beer was so "grapy" that is smelled like cheap wine. I plated the culture and transferred a couple of isolates to slant. I then grew a culture from slant, re-brewed the same recipe, and the resulting beer was very good.

[orlando]

You can't charge £6/7 for a slant.

Brewlabs do.

Thanks for the warning.

[McMullan]

I wouldn't say an orbital shaker is much like the shaken-not-stirred method. Entirely different. I distinguish between them and plan to assess both in my experiment. An orbital shaker, the method of choice in a culture laboratory, applies a continuous swirling motion without foam production.

Your assertion is correct. My method is a radical take on basic shaking. Stumbling upon it was purely a case of serendipity. However, I would say that my method is closer to an orbital shaker in action than a stir plate. An orbital shaker is capable of producing foam without exposing the cells to impeller shear stress. If a stir plate was even remotely close to an orbital shaker in action, labs would use use stir plates instead of orbital shakers. A used small orbital shaker is still significantly more expensive than a stir plate.

Most useful discoveries were stumbled on serendipitously.

[McMullan]

I grow almost every culture that I use in brewing from slant, so I am torn between agreeing and disagreeing on whether or not slants are superior to liquid cultures. One advantage that a slant has over a liquid culture is that the cells on a slant where grown in the presence of 21 parts per hundred oxygen, which makes a difference in sterol and UFA reserves. On the other hand, slants get old too.

A lot of the difference in performance that you are experiencing in the UK is due to age and handling. Liquid cultures from the big two liquid culture producers here in the United States have to travel almost 9,000 kilometers while being exposed to all kinds of stresses to reach the UK. I had to re-plate every Brewlabs slant that I received. Having to re-plate the cultures should be construed as an indictment of Brewlabs' quality. It was an acknowledgement that the yeast cells experienced a lot of stress during their journey. For example, my Somerset culture was so stressed that it threw a metric truckload of ethyl heptanoate. I am a big fan of that ester, and it was too much for me. One of my children remarked that the beer was so "grapy" that is smelled like cheap wine. I plated the culture and transferred a couple of isolates to slant. I then grew a culture from slant, re-brewed the same recipe, and the resulting beer was very good.

Shame to hear about a yeast slope struggling to reach the US, from anywhere really. I agree, a well prepped slope with healthy yeast cells should travel without problems. It takes 7-14 days for yeast slopes to reach my grubby hands. I find yeast on slopes have a longer shelf life compared with yeast in liquid. I wonder if it's because yeast in liquid might be artificially overpopulated in commercial packs therefore more at risk from stress factors, e.g. starvation? A kind of 'Tragedy of the Yeast Pack'. Whereas yeast on slopes grow to a more natural/sustainable population size. Purely hypothetical, but there must be cause effecting the difference.

[f00b4r]

In terms of going from a Brew Lab (or home made) slope using this method what would be your recommendations (travel stress for the Brew Lab slopes should not be an issue as they are based in the same area as me)? I have a pressure cooker as well so plan to start pressure canning starter wort and sterilising the stainless steel funnel as well when required, along with the ease of access to suitable 5L water bottles here seems to make this method a no brainer for me to use with vials at least.
I am really interested in McMullan's investigations on it as well though, definitely one of the more informative and interesting threads in this forum (especially with some of the back and forth)

[donchiquon]

First time trying the Bond method for me. I usually repitch slurry within a week, but this time my jars are 4 weeks old.

I now have a litre of mafia-battered wort in the brew fridge at 20 deg.

Unfortunately the slurry sample had a lot of trub and hop in it. I can see it all sitting at the bottom of my 5L bottle.

Once it hits high Krausen tomorrow can I decant the active yeast and leave all the trub behind, or should I pitch the lot? (Guessing the former but wanted to check). Thanks!


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[donchiquon]

A couple of hours to go before pitching. Loads of action going on in the bottle and - tight thick head about 1-2cm deep on top. Worryingly this is looking a bit green and hoppy....I should definitely have decanted the original slurry a bit better.

There is still a centimetre of what looks like hop and trub on the bottom. If no one advises otherwise I think I'll just decant the liquid above.


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[Jocky]

If you're worried about it I think that would be best - as you pour off the liquid the top layer of settled Yeast should come with it, giving you plenty of active yeast.