Outstanding sugar wash pH questions

[Harley]

Hi everyone, any answers/indications to the below questions are really appreciated!

It's known that the pH will crash in sugar wash ferments. Please consider the common Birdwatcher recipe for the below questions:
1. pH drops throughout fermentation due to yeast excreting lactic acid - what influences the lactic acid production? Yeast type, recipe, pitching rate, temperature, ferment pressure, nutrients, etc.? Why does it crash when beers don't?
2. Yeast will be shocked by fast pH changes. Is this why over-pitching is a problem (due to high initial fermentation rates) ?
3. Ways to slow down the pH crash are to decrease pitching rate (to decrease activity), decrease initial pH (conventionally 5.2-5.4, but maybe take it a bit lower?), or to add pH buffers (live oyster shells for small ferment volumes only). Sounds right?
4. pH needs to be adjusted within the first 6-12 hours of fermentation to keep the range between 4.5-5. This should be done with oyster shells (as a pH buffer) for smaller ferment volumes, calcium carbonate for intermediate volumes or calcium/potassium hydroxide for larger volumes (based on practicality). Sodium hydroxide shouldn't be used since sodium it isn't a yeast nutrient (unlike the others which aid fermentation, potassium is preferred). Sounds right?
5. What is the typical pH tolerance (point at which fermentation stops) for baker's yeast?
6. Regarding pH crashes, does anything change when scaling from a ~60L wash to a ~200L wash?

Thanks in advance

[NZChris]

It's known that the pH will crash in sugar wash ferments. Please consider the common Birdwatcher recipe for the below questions:
1. pH drops throughout fermentation due to yeast excreting lactic acid - what influences lactic acid production? Yeast type, recipe, pitching rate, temperature, ferment pressure, nutrients, etc.? Why does it crash when beers don't?
2. Yeast will be shocked by fast pH changes. Is this why over-pitching is a problem (due to high initial fermentation rates) ?
3. Ways to slow down the pH crash are to decrease pitching rate (to decrease activity), decrease initial pH (conventionally 5.2-5.4, but maybe take it a bit lower?), or to add pH buffers (live oyster shells for small ferment volumes only). Sounds right?
4. pH needs to be adjusted within the first 6-12 hours of fermentation to keep the range between 4.5-5. This should be done with oyster shells (as a pH buffer) for smaller ferment volumes, calcium carbonate for intermediate volumes or calcium/potassium hydroxide for larger volumes (based on practicality). Sodium hydroxide shouldn't be used since sodium it isn't a yeast nutrient (unlike the others which aid fermentation, potassium is preferred). Sounds right?
5. What is the typical pH tolerance (point at which fermentation stops) for baker's yeast?
6. Regarding pH crashes, does anything change when scaling from a ~60L wash to a ~200L wash?

Thanks in advance

#1 pH also drops due to CO2 production.
#3 Live oysters might be ok in something like rum. It's a very 'out there' suggestion, not something I would use for neutral. Try them yourself and let us know how it goes. Calcium carbonate does not buffer at any pH safe to use for distillers. It can be used to emulate a buffer in an active ferment, that's all. An excess of CC, given enough time, can wreck a wash.
#4 None of those suggestions happen in my shed. Where did you get them from?
#6 Not that I've noticed, not that I'm likely to. I add large whole shells at the start, or the next day, and seldom check the pH again until the ferment goes dead. I seldom have a problem with speed and when I have checked pH, it's always been ok.