Just to add a thought, I feel that old world traditions and approaches to making cheese made for better cheese. One of those approaches was to combine evening and morning milk. There was no such thing really as a storage tank, and you couldn't make cheese twice a day most of the time, so you would make it every day in the morning after combining the milks. But, that evening milk sat for 6-12 hours, subject to bacterial action. So it would be pre-acidified naturally and have natural bacterial populations. In my milking, if I leave milk in the cellar at 55-60 from the evening milking, the pH is usually .1-.3 lower (from 6.45 to 6.3 most of the time, goat milk, different for cow). When you add this preacidified milk, what you got were huge colonies of bacteria right away, and some of the protein (casein) had solubilized.
This traditional approach is completely abandoned with the idea of DVI. With DVI, you have a "preripening" stage where you let the bacteria wake up. And the theory is that with that wait, you start at the same theoretical point as using either overnight milk of mother culture. But it's not the case for a few reasons. One, modern culture strains are selected for speed, to acidify quickly. Think about some of our favorite oldest cheeses. Stilton, roquefort, ossau iraty, tommes, etc. They were not cooked for the most part, or cooked just a little to 95-100, and used slow cultures. Modern practices push that to 103-104F, to decrease make times, and use fast cultures. But the cheeses are not as good. Two, when you add DVI bacteria, you are adding the same number, in theory, but they are at a different stage than live and active bacteria. So even though the number of bacteria may be the same, and the pre-ripening takes care of waking them up, the pH curve is still way different. It's just not the same.
Modern science has tried to reintroduce the physics behind this preacidification by manipulating the milk. One common example is by bubbling Co2 through the milk to bring the pH down to 6.5 (most often used rennet point for cow cheese). Another is by using a small amount (.2%) of FD or MM or similar culture, and then re-pasteurizing. And another is by using glucono-delta-lactone to preacidify, or a harsher acid like lactic, citric, acetic, or formic. And it's all with the idea of achieving this pH drop before going into the make.
For people making cheese regularly, DVI mothers are a brilliant approach.
Troy, the point is just that, that you don't need to maintain starters. You don't need to do the old method of re-inoculating each batch and fighting changes in the culture mix and all that kind of stuff. Simply, create a workflow and one day before each make, figure out the amount of starter you need, boil the skim milk, cool inoculate with a small amount of the starter culture, and let it go. It's basically exactly like making yogurt. It does take a little bit of planning, and some equipment, and a dedicated space, but it's like milking. Once you have it all set up, you can milk 8 does at a time by yourself pretty easily.
Thanks for doing this, Sailor. I have a draft done from a few months ago on different rotation options used in the industry to maintain starters, but, of course, no time to finish completely right now.