I’ve been doing a bunch of reading on this starter method and am planning on giving it a whirl for my next brew day (tomorrow or the next day depending). I’m going to be making 5.5 gallons of 1.060ish lager with harvested 34/70. I’ve got a WL vial of the yeast that I wanna use and am not sure how many liters of starter wort I should make. I’ve got a bunch of 1 gallon demijohns so no problem for the 3-4 times larger vessel. My plan was to make the starter this evening and pitch tomorrow around mid day, once the wort is chilled.
Its my understanding that I can get away with a much smaller starter volume by doing this method which is great because I’m not really interested in spending a week building an enormous starter. Am I right in thinking that most who use this method are doing a 1L starter for 5 gallons of ale? If so would a 2L starter work for my 5.5 gallons of lager (almost doubling the pitch)?
Any help or advice from the bigger heads here would be greatly appreciated. Thanks in advance…
I am guessing the shaking method you are referring too is the one in which the starter is in a soda bottle and intermittently the bottle is squeezed to push out the “stale” air in the bottle, allowed to suck in fresh air, and then shook to mix the fresh air with the wort. However, demijohns cannot be squeezed. From the yeast calculators, shaking is better than a normal fermentation, but not as good as constant stirring.
If I was to do the shaking method, which I sometimes do, I would make 2-3 L of starter after checking with a yeast calculator and divide the starter between two 2L bottles.
He is talking about Mark V’s “shake it like it owes you money and pitch at high krausen” method. I can’t answer your question, but I am sure Mark has answered this previously.
I’m going to try to articulate in my pea brain terms what I think Mark has been saying.
His shaken not stired, pitch and high krausen method is not about pitching the correct number of cells. Its about pitching them in the correct state. So, assuming a fresh smack pack or vial, you prep 1L of starter wort by putting it in a vessel at least 4 times as big. The 3/4 empty vessel leaves enough space to shake it till its at least half foam. Pitch the smack pack or vial and cover with foil. It should reach high krausen at 12-16 hrs, at which point you pitch the whole shebang to your brew. The starter will have fresh healthy cells that are ready to continue reproducing, rather than cells that have finished and gone dormant.
I’m not convinced I’m rewording what Mark has said correctly, and thats kinda why I did it. Now he can come along and correct me. And then I can learn it more better.
This is what S.cerivasai was saying in a similar thread. He also advises against using a stir plate as this stresses the yeast. What is the argument for/against employing a stir plate when making a starter?
I believe the argument for using a stir plate is that it does continuously oxygenate the wort if a vortex is achieved. Mark’s point is that the forces present in a starter that is stirred at such a high speed will cause damage to the yeast cells. It seems it’s not so much a biochemical problem but a physical one. Apparently all that slamming around during long periods of stirring is detrimental to the cell walls of the yeast. The shaken not stirred method does employ very vigorous/violent stirring (shaking) but it is for a very short period of time (1 min) such that there is really no physical stress to the yeast. I take his method to heart and really shake the living daylights out of that one gallon jug to the point that the whole 1L starter is completely foam. The maximum degree of air-to-liquid surface area is achieved in that condition.
The method is informally called “Shaken, not Stirred,” or the “James Bond Method.”
OP:
I never pitch larger than 1L per 5 gallons of normal gravity wort. It does not matter if the batch is an ale or lager. The only reason that doubling the pitch rate can be justified is that the length of the replication period is bounded by the metabolic rate, and the metabolic rate is slowed at lower temperatures. However, one of the reasons why lager brewing made brewing possible on an industrial scale is that cold temperatures slow, if not completely stop the replication of wild microflora.
The only time that a stirred starter begins to approach the surface area of a Shaken, not Stirred starter is when a vortex is created. The vortex is needed overcome the low amount of surface area that is present when a 1L starter is made in a 2L Erlenmeyer flask as well as to overcome the geometry of a Erlenmeyer flask by creating a vacuum. A stir plate cannot overcome the poor geometry of an Erlenmeyer flask once the culture starts outgassing.
When we use a stir plate to propagate yeast, we are using a process known as stirred suspension cell culturing. Shear stress is a well-known problem with stirred cultures. Shear stress is the stress placed on cells in turbulent flow. The more turbulent the fluid, the greater the amount of shear stress. I am convinced that the foul odors and tastes that one encounters with a stirred starter are the result of stress, not oxidation, as oxidation should not occur in a culture due the cell density and yeast’s affinity for O2.
Shear stress in stirred cultures is a well studied problem. While we think of growing yeast biomass when the term culturing is thrown around, many other types of cells are propagated using the same basic techniques that we use for yeast (the medium may be different). A device known as a bioreactor is used for very large scale cell culturing and dry yeast culturing. There are numerous papers covering this area of research.
Yes, the key to success with the method is shaking the medium vigorously enough to turn it completely into foam (or at least darn near it) in a vessel with at least a 4:1 vessel volume to medium volume ratio. Gas dissolves into a liquid at the interface between the gas and the liquid. The Shaken not, Stirred method works by creating a huge amount of surface area. A gas-liquid foam has a very high specific surface area. It is basically pockets of gas encased in thin layers of liquid. The beauty of the technique is that the O2 that dissolves while the medium is still foam is available immediately to the culture.
With the above said, shaking can be eliminated via direct O2 injection. However, the technique is no longer low tech and low cost (or as my British friends would say, no longer as cheap and cheerful).
While there is a lower bound beneath which we should not go cell count-wise, Jim’s assessment is correct. We are not making beer with a starter. We are propagating yeast; hence, we want to try our best to keep the yeast biomass in exponential (a.k.a. logarithmic) growth mode (we should use the same technique when making a stepped starter). High krausen occurs when the yeast biomass reaches the point marked deceleration phase on the graph shown below. We want to avoid having the culture enter the stationary phase because biomass growth from that point forward is for replacement only, and any replication from that point forward wastes ergosterol and unsaturated fatty acid reserves.
Mark, how is this method much different from pitching a gently stirred starter (just enough action to keep the cells in suspension - all things being equal - proper O2 and nutrients) pitched at high krausen?
First and foremost, brewing yeast cells do not need to be stirred to remain in suspension, at least not before high krausen is reached. Most brewing yeast strains exhibit what is known as NewFlo flocculation (the genes that are responsible for flocculation are known as FLO genes). NewFlo strains do not flocculate until glucose, mannose, maltose, sucrose, and maltotriose have reached a genetically set level.
At this point, the only positive that stir plates bring to the table when propagating brewing yeast strains is degassing of the medium. However, CO2 build up is not much of a problem when a culture is pitched 12 hours after it is inoculated.
To answer your question, is why would one want to use a stir plate when it basically brings little to the table and risks exposing the cells to continuous shear stress (even a slowly stirred culture undergoes turbulent flow)? Why not just go with an easier and lower cost method that does not unnecessarily waste resources? If stir plates are the answer, why do we not stir our batches of beer? It would be easily to do with a continuous duty motor and a sanitized stainless steel paint stirrer. A batch of beer would more than likely benefit more from continuous stirring than a culture because stirring would keep the cells in suspension long after glucose, mannose, maltose, sucrose, and maltotriose levels have fallen below the levels encoded a yeast strain’s genetics.
I was referring to continuously stirring a 5-gallon batch with a stirrer and a motor. I know very few people who would be able to shake 5 gallons of wort that vigorously.
I am not attempting to make anyone’s life more difficult. In fact, I am attempting to remove a barrier to entry and reduce the complexity of moving to liquid yeast cultures. So many new brewers today believe that a stir plate, a stir bar, and an Erlenmeyer flask are required to produce a healthy liquid culture that many choose to stick with dry yeast. A one U.S. gallon glass jug can often be acquired as waste that once held juice or vinegar. Thirty-eight millimeter polyseal reusable caps can usually be had for less than a dollar each. It does not get much lower cost than a glass jug that would have more than likely found its way into a landfill and less than a dollar for a reusable cap. That sure beats $70.00 to $150.00 for a stir plate, a couple of dollars for a stir bar, and another $20.00 to $25.00 for a 2L Erlenmeyer flask. A process does not get much simpler than shaking. All one needs to do after inoculating and shaking or shaking and inoculating is to loosen to cap enough that the culture can outgas, and then wait for high krausen to appear.
Mark, I haven’t used you method as I have been simply been getting fresh smack packs and brewing sub 1.040 beers that I then repitch at a thick rate of 60-100ml into my later batches. I do plan on trying it but will likely crash at krausen or pitch into 1 quart of the actual beer shaken to foam. That said, have you brought this to HBT or BN Forums yet? Not flaming, just curious if you had and what sort of reaction you received.
I want to say that now that the weather is turning cooler, the brewing will resume. The first beer will use US-05. The next will be some 022 Essex, and I will shake that starter like it owes me some big money. Will do a liter in a 4 liter jug to be more Metric in my process. I am an engineer!
