Agreed, but a stir plate does help reach maximum cell density for a large starter (3-4L) in my experience, which is very helpful when making 10 gallons of lager or high gravity ale.
I’ll do that after my next starter, as long as I can get my cell phone camera to cooperate with my student microscope’s eyepiece.
Got one and use it every time I make a starter.
Fortunately, one was given to me, so no money wast wasted. And I still can’t reconcile my personal results with your “best practices”. My own experience is that using a stir plate and decanting produces better beer at my house than shaking the starter and pitching at high krausen. I respect the science, but I must be in some sort of Bermuda Triangle of non-science since it doesn’t work like that for me.
I am actually working on a blog article looking at this. A friend spent the big bucks on an orbital shaker table some time ago. I have a stir plate. Planning to pressure cook wort and the stir plate, shaker table and shake method and do some viability and counting, fermentation with split batch wort. I may try to weave in a dry v rehydrated version as well… but with very rough manufacturer cell estimates in dry yeast, not sure it would be valid.
In the “Selecting Yeast Based on Strain… yada longest seminar name ever” Kevin Lane said their pitching rates were based on biomass (dry weight) and not cell counts, advice that follows closely with Mark’s recommendations. They are also adjusting their viability recommendations quite a bit. I was pretty surprised frankly… it’s a large shift from the White Labs and Wyeast advice, but it was also seemed to be inferred that WL was propagating to mass in their new process and that the cell counts were significantly increased in their new process/packaging.
I was surprised in Kevin’s advice on pitching dry and not rehydrated, but apparently they don’t see in their labs the significant yeast die off from pitching into wort that others have reported. I “seem” to get better results with rehydration, but willing to admit personal bias. I spoke with him briefly after - he said the difference was really in lag times and not in ester/phenol expression. It was a bit boggling as I have done side by side tests with meads (1.100 gravity must) and the results were very different between 71B-1122 dry pitch and rehydration with GoFerm (as recommended by Schramm and Pietz), with the sugar break feedings.
I was reading a paper on shaker tables last night. One thing I found interesting was that the author claimed that the media volume should be no larger than 25% of the flask volume in order for the technique to be most effective. This publication parallels my finding with well-shaken starters. In the case of the shaker table, a media volume of 25% or less of the flask volume increases the surface area that is exposed to air. My rationale for having at least that much extra volume is that it allows for expansion during shaking. Media (wort in this case), when expanded to foam, has significantly more surface area than media in pure liquid form. I wonder how much more effective a stir plate spun at a slow enough speed to prevent shear stress would be if the media volume was limited to 10% of the flask volume. Given two flasks of the same size with the same amount of media, the flask placed on the shaker table would have a larger amount of surface area than the flask placed on a stir plate due to the shaker table’s orbital pattern causing the media to slosh up on to the sides of the flask.
I have never noticed any negative effects from shearing when making starters on a stir plate and feel comfortable recommending that as a propagation technique.
I like the comment made by Narvin about “After trying their beers at the tasting room, I’m not sure I trust their palate on brewing advice.” Similar experience on my end. Yeast biologists grow great yeast, and maltsters malt great malt and hop growers grow great hops but when I have tasted their beers I have not usually been very impressed. Leave the brewing to the brewers.
I thought the point of the beers in the tasting room was to compare what different yeast strains do to the same base beer. In that vein, the ‘standard’ yeast should be a good beer (which applied to the two flights I tasted), and then anything ‘off’ in the others is going to be the result of the interplay of the style with that yeast strain. I get the impression they don’t try to get complimentary flavors as much as highlight what the yeast does. Some of those wind up making an interesting and different good beer, and some wind up being a train wreck.
Yes, but I didn’t love the’ standard’ beer of any style. The closest was the hefe with 300, but it still wasn’t my favorite.
Keith, I haven’t found detriment to my stirred starters since I typically stir slowly and use a 3" stir bar. But I don’t doubt that a shaken vessel could be better than stirred. My point is that this appears to be a case of ‘good and better’. Stir plates are still good and should be used, if you have one. Most of us won’t have the opportunity to move up to a shaker like White Labs has.
I wouldn’t expect to love any of their beers though. I would just expect them to be middle of the road examples (something I would score in the mid-30s in a comp for example). Their goal isn’t to make beers I love. It’s to propagate and sell yeast. They only have a tasting room to highlight what the yeast can do.
Agreed. I wasn’t necessarily disappointed since the comparison was interesting, but I wouldn’t follow their brewer’s advice for making beer above all others.
When I got my stir plate, a friend in the club gave me some stir bars that have a “raised ring” in the center that the bar rotates on. He said that those were easier in the yeast than a flat stir bar.
Any thoughts?
You two need to agree to disagree and stop arguing about stir plates. You’re going to drive me mad.
Personally, I like my stir plates. I think they’ve helped me to improve my pitching rates. But do whatever works for you.
People get too dogmatic about things sometimes. There is more than one route to the production of great homebrew, and that’s one of the great things about the hobby.
I’ll do it my way, you do it your way.
Don’t know if they are or not, but that’s what I use. I also use a gal. jug for my container, so I’m at least somewhere in the ballpark of Mark’s comment about limiting wort size.
I have never used a stir plate, so I cannot comment on their effectiveness or detriment, but I can say that they are absolutely not necessary. I have always followed the “shake it whenever you walk by it” method of aerating starters, and it has always worked fine. I did notice a big improvement when I started using the “Shaken, not stirred” method of starter aeration. My starters have taken off more rapidly, smell better (I take this as a subjective sign of yeast health), and have noticeably shorter lag times when pitched.
I’m not saying that everyone needs to toss their stir plate, but it is by no means a required piece of equipment. Your money is much better spent on a temp controller, a new keg, a sack of grain, etc. - unless you’re a gadget addict and just want one for the fun of it.
I don’t think anyone was implying that you have to have a stir plate (or shaker table!). I know I certainly wasn’t. I did the shake thing for years and it worked fine. I’ve found that a stir plate lets me make starters in a shorter period of time, but I still wouldn’t have one of someone hadn’t given me an old one.
There’s nothing magical about my method. It’s just a low cost, low-tech way to dissolve O2 into wort that’s based on physics. Wort in foam form has a huge amount of surface area compared to wort in liquid form. Foam maximizes the gas to liquid interface because gas-liquid foams have a very high specific surface area. The yeast analogy of Denny’s claim that malt wants to become beer is yeast cells want to multiply if given O2, carbon, and room to multiply.
No disagreement from me. I don’t use a stir plate very often any longer but I can honestly say that it improved the quality of my homebrew over standard starters. I also have great, perhaps better, luck with constant aeration starters. I’m sure a shaker table is the best of both worlds, and from a lab perspective Mark is absolutely correct. But from a practical perspective he is way off the mark. It’s like telling someone they can’t get to work in their Honda Civic because a BMW435i is the preferred method by Car and Driver magazine.
I stand by my assertion that a stir plate is an unnecessary expense that most modern home brewers are led to believe is a necessary expense. Agitation does not buy much with most brewing strains because they are NewFlo strains. The keys to healthy growth are adequate O2 and carbon.
My stir plate was free. And it does a demonstrably better job for me than just shaking the jug when I go by.