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What Is The Difference Between A Stir-Plate and James Bond?

Let's Brew Beer

Let's Brew Beer!
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I'm yet to invest in a stir-plate, so does that mean I'll never have healthy, pitchable yeast, with a decent cell count? Perhaps there's a silver lining. Find out in the latest video. Check It Out!
 
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Lots of oversimplification there. Nobody has ever said a stir plate is a requirement to a starter, and shaking has long been used as a replacement. Cell counts do not get as high with this method but they still multiply. Using an O2 Stone and a cheap little O2 tank from a hardware store is also a highly effective method.

Kai has done an amazing job documenting many methods and the results of which here


if you're not familiar with his blog/site you should give it a look, tons of amazing info.

 
There is no science supporting this "James Bond" method, just flawed logic that doesn't really apply to biology or yeast cells generally. For instance, "shear stress" is associated with fragile mammalian cells used in in vitro assays, not tough-as-old-boots yeast cells. And the physics of a foam have very little effect on yeast cells, because dormant yeast cells invariably settle out on the bottom of the starter vessel for the first several hours. All the shaking has simply aerated the wort. Note shaking to aerate/oxygenate growth media has been standard practice for decades.

The fact is, all yeast starter methods work, as long as viable yeast cells with high vitality get exposed to resources and conditions required for growth. Even just leaving the starter in a cupboard without any intervention works just fine.

Home brewers are notoriously superstitious, though. Ironically, pro brewers focus more on repitching yeast than making starters. The first pitch is just the beginning and usually suffers with an aberrant fermentation due to underpitching for one reason or another. Freshly harvested yeast repitched is the best for free 🤫
 
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The bottom line is you should do what works for you. If you believe a stir plate works best then by all means use the stir plate. If you try the SNS method and like it, likewise keep doing it.

I've been using the SNS method for almost 7 years ever since I found an article on Denny Conn's blog, Experimental Brewing. I like the simplicity of it and that I don't have to plan my brewday several days in advance. In the past there were several instances where I suddenly had a day off the next day and could brew... but I didn't have a starter ready. When I discovered the SNS method suddenly needing 24 to 48 hours to get the starter ready was not an obstacle. However both methods have a place in my brew house and I will use a stir plate when it makes sense.
 
The bottom line is you should do what works for you.
Absolutely, and it's very helpful if we understand why something works or doesn't work. The SNS/"James Bond" method is just about aerating wort really. I don't recommend vigorously shaking a 5L glass lab bottle, after breaking one during testing. A very expensive mistake. A little pure O2 through a sintered stone is a much easier way to get oxygen into starter wort. All things equal - yeast number, vitality, etc. - there is no statistically significant difference for fermentation based on starter method. I can't remember the last time I used a stir plate, tbh. I repitch fresh yeast mainly. I probably make 3 starters a year now and just leave them in the cupboard for 3-4 days before pitching in a half batch. Repitch several times then take a break until my kegs are empty. Binge brewing, I guess. It works for me.
 
I've recently turned to the vitality starter advocated by Colin Kaminsky, who picked it up back in 2002 from a brewmaster at Coors England: Spin the yeast you'll be using for four to six hours in a starter on a stir plate prior to pitching, and dump the whole thing in. Do not oxygenate the wort.

This has worked very well for me, so I'll stick with it. I do not trust the SNS to supply enough oxygen to build sterol stores up to max, so if I use that, I feel I have to oxygenate the wort - and it's nice to be able to skip that.

Reusing yeast is great, and if you take the yeast from a healthy fermentation, you should have good glycogen stores. But those will be depleted fairly quickly in storage, so you should not wait long before using it. The breweries do not. You must supply plenty of oxygen, because the sterol levels will be low in yeast at the end of the fermenation, but with good stores of glycogen to fuel the synthesis of sterols, you'll have no worries. But that's also why you don't want to wait long before using the harvested yeast.

So if you can't brew within a few days from harvesting, I think you should refresh the yeast. Give it some 1.020-ish wort, spin it for some time, and then let it sit with an airlock to let it replenish the glycogen stores. It will take a couple of days. Then you might either use it as it is, but with oxygenation, or you can use a Kaminsky vitalizer (without oxygenation). The latter will give you a shorter lag time.

I feel that combining a refresher and the Kaminsky vitalizer optimizes your chances of a good fermentation. But that's just based on my own recent experiences with a series of pilsner batches.

Reusing means you'll not be using only the very best yeast - at least not when bottom cropping after bottling or kegging. I'm not sure how much of a problem that actually is, but I'm fairly certain it limits the number of times you can reuse the yeast. A solution might be to take some of the fermenting beer at hight kräusen - say 24-72 hours after pitching - and build up new yeast from that. That's advocated by the Weihenstphan laboratory, but might seem a bit too much trouble. I does to me, so I haven't tried it yet:).
 
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