Are you sure we're not related, Paul? Brewer, trained French chef, mad scientist lab, ever decreasing kitchen and house space due to "hobbies"... understanding wife... You even have the anglicized version of my name...
That said, I am interested in encouraging a natural mold development, but do not know how one goes about encouraging beneficial flora, and discouraging harmful molds.
You do this by seeding the environment you want with the flora you want, fighting against blooms and outbreaks of undesireables, and giving the flora favorable conditions.
The thing is, the favorable conditions are ~90% humidity, and 50-55F for most of the flora you want, and also for the flora you do not want. If those environmental variables stay the same, they all will compete for the same food, space, and other resources. So if that competition exists, and you keep seeding with good molds, and removing bad ones, eventually the cave will be at a sort of uneasy truce and equilibrium. Note, you need a sizeable space to do this, and you need good air movement and air exchange. You can't do this in a fridge, for example.
To draw a parallel to beer, in warm wort, you can get yeast, lactobacilli, acetobacter, and a whole bunch of other stuff to grow. You don't want those, most of the time, so you control it by sterilizing, boiling, CO2 gassing, etc.
Here's a quick rundown on the most common flora types and their preferred conditions:
- Geotrichums like 92-95% RH, high O2 levels, and 52F, and up to 5% salt, depends on variant
- Penicilliums, both roqueforti and candidum like very high O2, 95% RH, and 50-55F, salt tolerance usually at least 4%, can be as high as 10%. Likes dry rind to bloom.
- Debromyces and Kluyveromyces like standard yeast conditions, 55-60F, sugar, nitrogen source, etc.
- Misc Streptococcus like 2-3% salt, can be higher, pH >5.7
- B linens likes 98% RH, 52F, 3% salt min, 14-15% salt max, pH >5.8
When you are crafting a rind, it is about knowing the cascade of blooming/growth of the ecology, and the controls you have to encourage dominance of one species. Controls are temp, humidity, salt, oxygen. Very often on the forums you will read rind answers from me that start with "it depends". It's not straightforward, but there are proven ways to create specific types of rinds, which is generally what I ask about in order to answer.
Any thoughts, specifically, on species involved in a classic tomme de savoie, at least broadly speaking?
Yes, multiple native geotrichum strains, arthrobacter, b linens or other corynebacteria, possibly Rhodotorula. You can buy a piece of tomme de savoie and isolate the strains and culture them if you want exact replication. Similar to yeast.
If you want a cheaper/easier trial solution, take a tomme rind, puree in distilled water, and both add that to milk, and make a rind wash from the puree, and it should give you a similar outcome.