a starter that small scares the hell out of me. fermentation has always been like magic to me in that I follow instructions and guidelines and hope for the best. why even make a starter? what is the starter doing for me here? is getting the yeast going in the right amount of starter the main issue and then after that it just doesn’t matter much? we are talking the difference between something like 80B cells and probably less than 200B cells (just guessing after making a 2L starter) when most experts out there would say I should be pitching close to 600B or more.
A 2L starter is not a small starter by any stretch of the imagination. I do not know who the “experts” are, but I would love to see their sources. I am willing to bet that their guidelines are based more on folklore passed down from other brewers who received the information as folklore from other brewers than anything grounded in science. A 2L liter starter pitched into 10 gallons (38L) is a 1:19 step. That’s well within the realm of a healthy culture that is pitched into well-aerated wort. It takes log(19) / log(2) = 4.25 replication (doubling) periods for 400 billion cells to grow into 7.6 trillion cells. It’s just basic biological science.
By the way, there are two major reasons why we use a starter. The first reason is to lower the probability that wild microflora will gain control of the batch. Bacteria multiply 8-fold in the same amount of time that yeast double. The second reason why we make a starter is to bring the culture out of quiescence before pitching, which reduces lag time, which, in turn, allows the culture to start reproducing faster. The faster a culture starts reproducing after being pitched, the lower the probability that house microflora will gain a foothold in the fermentation. Every other reason is subordinate to these two reasons.
According to the Mr. Malty website, the metric used by that particular yeast calculator came from George Fix’s book An Analysis of Brewing Techniques.
Someone who owns a copy (I do not) might be able to trace it further. Maybe it’s been superseded at this point.
Mark- is this math suggested for 5 or 10 gallons?
the experts? Chris White/Jamil or whoever contributed to the pitching rate calculators out there. I’m not saying you are wrong or anything but you must at least realize what you are saying flies in the face of what most people have been doing for years.
page 122 of Yeast. # cells to pitch = 1.5M * mL of wort * deg Plato, which is around 700B in the case of my example lager.
But back to your process…
can I make a shaken starter in a flask? will foil on top keep things from leaking out and making a mess? Also, in the case of the 10 gal of wort, can I over oxygenate it with pure O2 or is this simply not possible?
I guess what mark is saying is that if your yeast are at healthy high krausen you don’t need 700B because they will go from 300B to 600b to 1.2T in about an hour and a half
This sounds like a ver succinct and accurate interpretation.
I think it’s important to note that Mark isn’t saying this method is a replacement for any others. It’s just easier, less equipment intensive and guided by biology to provide an extremely active and healthy starter.
Looking at Mr Malty, the only thing contrary to what Mark says is that Jamil claimed a stirplate is the best way to continually add oxygen. Other than that, jamil says 1gm dme to 10ml water, oxygenated, pitched at high krausen, which he quotes Doss from Wyeast as esimated to occur with a fresh sample in a 2L starter in 12-18 hrs. What Mark is saying is not really contrary to the basics on the Mr Malty site. I think the discrepancy regarding recommended cell counts is due to the calculator being designed for using yeast starters that are fermented out, decanted and pitched, rather than at high krausen.
Im not as far along as Denny in my trial, but so far I can say that my oxygenated and shook starters of 1056 smelled fantastic as compared to my normal stirplated stanky ones. The fermentation took off like a rocket, I actually had some blowoff in my 30L Speidels that had 3 gallons of headspace with a 1.055 beer. That blowoff was just about 18 hrs in, thats when I found it, no idea exactly when it happened. The beer fermented out as usual in about the usual time.
I dont doubt Mark’s comments about shear stress on a stirplate, I just haven’t seen it with my own eyes. It makes sense though I dont know that its like the Bataan death march. You can’t duspute that a lot of great beer has been made with stirplate yeast.
I just think that Marks method does not fly in the face of current theory
10 gallons
A couple questions.
1. Can this shaken method also be viable when using a not super fresh pack/vial of yeast (i.e. as in a couple mos old?)
2. When doing a lager starter at warmer temps (70-75F) once it hits high krausen, the starter can be cooled to 50F prior to pitching into a chilled 50F batch of wort to minimize shock stress and off flavors of pitching into a warmer wort to obtain a cleaner lager profile?
I am curious as to where the calculator writers acquired their data. What I believe is going on with respect to pitching rates is that they are based on cropped yeast, which is a different animal. The stresses placed on yeast cells at the home brewing level are much lower than the stresses placed on yeast cells in a commercial brewery. Most home brewing fermentations have a fluid column that is around one foot tall.
Yes
I have already answered this question in this thread (page 4).
And “commercial” is not all the same, right? Are Budweisers fermenters the same size as Walking Man in Stevenson? The difference between commercial and home brewing may not be drastic when talking recipe percentages, water profile, hopping ratios and methods, but it seems like it has to be when it comes to yeast.
Mark, I’ve been following these “shaken not stirred” threads with great interest. Watching home-brewing knowledge progress is like a model of society at large; established dogma from “elders/experts” gets challenged by new data, followed by some pushback from the community, followed by acceptance as the “new dogma”. Repeat. Otherwise I would be still be pitching bread yeast into lager wort at 65 degrees, chilling to 50 after pitching, then racking to a secondary after the bubbles in my airlock slow to less than one per minute… 
What do you recommend for very high gravity worts of 1.090 and above? Wouldn’t the higher osmotic stress in these worts indicate a larger starter is required?
How long for the “second” starter? In theory I don’t see any big red flags with your plan.
Each yeast strain is unique, but higher gravity wort generally requires higher pitching rates due to the fact it is more difficult to dissolve O2 in high gravity wort, high osmotic pressure causes loss of turgor pressure, and lower dissolved O2 affects yeast cell heath. With a high gravity wort, it is best to use a strain that has been proven to hold its own against the double whammy of high osmotic pressure and high alcohol.
I always recommend using yeast cropped from a proven good fermentation for high gravity wort. In fact, I recommend using cropped yeast for standard gravity brewing over propagating a new culture. Cropped yeast has proven itself in one’s brewery, and it has also had time to adjust to one’s brewery. A brewer really does not know what a strain is capable of producing unless he/she repitches it a couple of times. I used to use a strain from BrewTek called CL-210 Scottish Bitter. The initial pitch was okay, but it was not until I had repitched the strain a couple of times that I started to appreciate its uniqueness.
Gotcha. Missed that even after reading it twice. Man, I need new glasses. Thanks!
Hi all, O.P. here…
I thought I’d give an update as to what I did. I originally was going to do the shaken not stirred starter with a vial of harvested 34/70 but I think it may have been too old because it did nothing in my starter for 3 days. I put off brewing while waiting for signs. I gave up on it and made 2l of starter wort, split it between 2 one gallon jugs and dry pitched half a pack of 34//70 in each. I shook like crazy and went to brewing. By the time the brew was finished and chilled, the starters were raging. I pitched them (on a friday) and left for the weekend, so unfortunately, I don’t know what kind of lag was involved but everything was cruising when I returned on the sunday. Today was racking day and the sample tastes amazingly clean and crisp, with no off flavours that I could taste. I’ve put it to lager for a few weeks.
I know what I’ve done isn’t really what Mark is suggesting but its kind of along the same lines as there are lots who would call one pack of dry lager yeast in 5.5 gallons of 1.062 wort (FG was 1.007), a severe underpitch which is guaranteed to produce nothing of a drinkable nature. I will definitely be trying something a little closer to Marks original technique on my next brew as well.
Thanks for teaching me something different Mark, I appreciate the shared knowledge…
It was a repitch. Not a new package.
Understood. Didn’t catch that.
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