Can you define 'right away'? Are you saying that with my raw milk and bulk culture combination, I should probably only wait five minutes before adding rennet?
Right away as in add bulk culture, stir, then add rennet. When I use it, I do the same thing as when I make yogurt. Take a bowl, ladle in some of the milk, maybe twice the amount of culture, then dump the bulk culture in the bowl, and whisk together so it's more runny, basically temper it in. Then pour it all in the pot. This way I don't worry about there being large chunks of starter in the milk on the bottom and don't need to stir very much.
Waiting for pH drop with bulk culture is a moot point. The only reason to measure it with DVI culture is to make sure the bacteria have rehydrated and are alive and eating food and multiplying. The reason to wait is that you want to start at the same point as you would traditionally with a mother culture, which is already active.
Farmer, it may be a good idea to reduce starter amount even more. This is especially true if you're using milk from the fridge that's 1-2 days old, as that will have more bacteria than same-day milk. If you had a 3-5 hour ripening time, I bet you wouldn't need starter at all.
Sailor, I figured you were posting a hypothetical... I wanted to run with it and try to think through the consequences. I'm not convinced it's possible to accelerate ripening that much. In my cheeses, slower has led to better results.
I encourage you to try a mother culture. You don't even need to worry about multi-generational propagation, just use DVI for each culture batch and don't reuse the culture. Take perhaps 1/10 or 1/8 of the usual amount of DVI (I believe the rate it 1/1000 DVI to liquid by weight, so 1 gram DVI to ~1000 ml milk), and the volume of milk to get you to 1-1.5%, microwave the milk in a canning jar, close it up, then wait for it to cool down, maybe help the process with a cold water bath. Then sprinkle a little of the DVI, seal, shake it up, and let it sit overnight in a warm place for meso, or your dehydrator set to 110 for thermo. Do this Friday evening and Saturday you can start the cheesemake.
This way, you should still get consistent results because your colony sizes should be the same every time (same DVI amount measures on a scale, same ripening temp). It does take a little work, and might not be worth it if you don't have time or are making normal sized 1-2 gal batches. It starts making a lot more sense for large batches because the cost savings add up.
I haven't seen this approach detailed anywhere else, presumably because you can only reliably culture most DVI once (the second time, the bacteria ratio will be different unless you're using a reculturable bulk starter like Abiasa's). Most of the time when people in the industry talk bulk starter vs DVI, they claim you need an expensive lab to do starter propagation because it requires aseptic handling, and DVI is open packet and pour. But I haven't seen the discussion of reculturing DVI for each batch, which is a hybrid approach and requires a lot less equipment. No need to keep mother starters in deep freeze, for example, and aseptic handling is easier because you could use a normal hepa hood and light a few bunsen burners in the working area to kill airborn bugs. Seal the container when you're done, toss in incubator for the night, and make cheese in the morning. Takes maybe $800 in lab equipment and makes the starter cost per pound of cheese somewhere in the 2-5 cent range, which is on par or cheaper than traditional bulk starter, taking fixed costs into account over their depreciable lifespan.
I know some of the best cheese plants culture their own. Rogue creamery for example maintains their custom blue strains in their lab.
Sorry I keep hijacking the thread. Got a little wound up there, like Farmer said
I went through this again and want to correct a slight error. It's a moot point to ripen with bulk culture for cheddar
. Because usually after addition, you get the correct pH drop right away due to the acidity of the bulk starter culture. There are many cheeses where you need to ripen past the usual 6.5-6.6 rennetting pH. For example, in a camembert, the milk is ripened longer, and it is also ripened longer in many blue cheeses.