Warning: Newbie question. Rind wash maintenance? Viability dropoff?

[ArnaudForestier]

Sorry, as I'm sure this is an obvious one (Linux, don't laugh...if I used to count yeasts, their viability and vitality, my cheese culture knowledge is less than zero; so, expectant of your usual expertise, I ask thus):

For a brine wash with a given culture - do you mix it up as needed, in small amounts, and do essentially a series of one-off washes?  If, like I intend to do, following on Linuxboy's advice, one ranches culture from a pureed rind and uses it to both inoculate milk and rind wash, outside of plating up the culture(s) and then banking them, how would one maintain their viability over the long haul of the cheese's aging?

[linuxboy]

I usually mix up one bucket for a series of batches and use it until it gets too smelly. Then I dump it and make up a new one. There's no hard rule, it's more of a practical matter. Thinking practically, if you could mix up one batch, and have the right ratios be maintained, and have it not get putrid over time, you could just use that one batch forever. But bacteria/yeasts/molds die... their waste products saturate the water, the pH changes, food is consumed, etc. So that requires a practical sort of approach of changing it whenever it seems like it's a good idea.

Another words, do it however you like . For me, one-offs would be way too much work.

The problem you described of viability is exactly the crux of the matter. You're actually asking 2-3 separate questions all grouped together, I think:

- When you have a piece of rind, how do you maintain multi-generational mixed-species cultures reliably without mutation, and without changing the ratios of the cultures
- How do you maintain general viability of a complex culture sample without knowing its composition
- How do you prevent contamination of a complex culture sample.
- After inoculating a cheese, how do you ensure the rind grows as expected.

And possibly other questions. Answers below:

There are two (good) approaches to cheesemaking as it relates to rind formation: one is ultra-controlled using engineered tools, where pure culture and microbiological techniques ensure exact repeatability, and the other is controlled by manipulating natural functions to maintain balance and arrive at the appropriate rind. They're actually both sides of the same coin, but very different philosophies practically. I feel like a person needs to understand oneself and one's inclinations, and adopt one as primary, and the other as secondary, and then pursue some course. So my answers to these questions cover both sides.

- When you have a piece of rind, how do you maintain multi-generational mixed-species cultures reliably without mutation, and without changing the ratios of the cultures

In the scientific world, using man-made tools, you do this as you said by plating, isolating, and banking. Then use aseptic technique and achieve exactly what you want.

In the natural world, using nature-made tools, you do this by establishing a multi-generational, stable flora in a cave, and on a cheese. When you have hundreds of wheels, all aging and having the same rind, and that cave has been stable for years, it's a fairly sure bet that new cheeses will develop a similar rind. And if not, a simple smear usually does the trick.

- How do you maintain general viability of a complex culture sample without knowing its composition

In the scientific world, by first culturing in broth using an all-purpose media mix, and then using either pure culture isolation, or a guesstimate of species to create a continuous or batch fermentation process. Have to remove the waste, and have to monitor conditions.

In the natural world, by having the good, wanted populations outcompete everything else. I'm talking about doing things like taking a bucket of wash and putting it on the walls. By having slow-moving currents of air to not remove airborne species. And, of course, by removing waste or transferring to new media or fresh environment. Can't have bacteria living in their own filth.

- How do you prevent contamination of a complex culture sample.

In science, by aseptic technique, differential agar, etc.

In nature, by outcompeting. You never really prevent contamination, more so you discourage everything else. Have to use the natural symbioses like the one between geo/yeast and b linens.

- After inoculating a cheese, how do you ensure the rind grows as expected.

In science, by practicing sanitation an using the controls I mentioned in the other thread of temp, humidity, inoculation amount, etc.

In nature, really the same thing, but perhaps more in line with the seasons, such as making b linens (instead of say a mycodore) smears in the winter here in the PNW when humidity is constantly 95+%

In the end, if you take a piece of rind, and the rind is fresh, then presumably you can get a good bloom and recreate the rind just by washing and inoculating the milk. Then in the next generation, you can use the rind from the cheese you just made and keep it up. In the wash, you can do the same thing. Take some of the wash, and put it into fresh brine mix, and start the second generation. When you do this at a small scale, such as for home use, and without a dedicated cave, it's harder to be consistent. Easier to take a piece of rind, make a slurry, freeze the slurry, and use that first gen blend to inoculate each time.

[ArnaudForestier]

Excellent, thanks as usual, Linux.  Yep, I think I was asking a few embedded questions, without being more specific and you elucidated them beautifully.  I could not really envision a means to maintain the complex culture over time, without isolating out individual strains and then banking them - and even then, as you mention, if it were truly an originating complex mix I was after producing from a given cheese I liked, I would think that even if I could successfully begin with a "close mix," generational mutation would be a nightmare. 

I muse on resurrecting my bio-lab of years earlier, but in truth so many years have passed (and so many iterations of crowding out family life with various "passions"  ) that I know that's not likely.  That aside, even if I can convince my wife "it's truly, really important stuff we're talking here..." heck of a lot easier to single-colony isolate out various strains of s. cerevisae, bank them on slants, and work them with known nutritional and environmental factors then this witches' brew of bacterias and molds. 

Hence, uh, yep, I get it, thanks again.  I hadn't thought of freezing the slurry, as I had thought that different species would differentially spaz out to the regimen as with sourdough starters (given that the bacterias don't cryolyze as readily as the wild yeasts, so over time you end up with a lesser and lesser percentage of yeasts - no data or evidence handy, just a vagues memory of reading something on it), so had some vague conception of trying for a slowed, controlled continuous bioactivity in a nutrient media of some sort.  No issue with freezing the slurry, and changes to the population mix over time?

Heading to a neighbor's, more later. Great stuff, Linux.

Paul

[linuxboy]

heck of a lot easier to single-colony isolate out various strains of s. cerevisae, bank them on slants, and work them with known nutritional and environmental factors then this witches' brew of bacterias and molds. 

That's true, pure culture isolation is tough business. But, not impossible. What you could do is differential agar based on the hypothesized species, which would narrow down the options, and then isolate and culture. You'd probably lose biodiversity this way as in the wild, you usually get 4-5 Geo strains, but it would be a fairly close approximation if you banked the individual strains. As a start, you could ID morphologically. Not 100% accurate, but it could get you a long way. The truth is, it's only 4-5 species/strains that contribute to the predominant flavor of a tomme in the rind. They outcompete everything else.

No issue with freezing the slurry, and changes to the population mix over time?

Absolutely an issue. Your usable life span would be 6 months at normal -15 degree freezer temps. If you used lyoprotectant and/or deep freeze temps of, say, -85F, you could bank the blend for a loooong time. If you're making on a small scale, it's tough to do slurries with complex blends. Easier to use commercial strains or your own pure strains. Unfortunately, it's as you said, yeast is easier to bank. But, so are molds. If you propagated the molds, you wouldn't even need to freeze them. You could suspend the spores in distilled water and they would last for years at fridge temps. I've been working on getting this technique to work with bacteria, but it doesn't work quite so well.

[ArnaudForestier]

Interesting idea on the differential agar.  My son was recently gifted with a decent microscope by his doting grandparents, so perhaps geekdom isn't too far off in the future after all...

I suppose I come at this with unclear goals.  Truthfully, what I was after was recrudescing some of the love I once had for yeast capture, propagation and ranching of favorite Euro ales, and a means to cheaply maintain rind flora than from buying up several different commercial strains (nothing like eliminating one production cost from a single colony  ).  At the end of the day, I'll likely just do some playing with rind slurries over the shorter run (asked in the other thread, you may not have seen it - but no issue with paste texture, using rind purees?), and otherwise deal with commercial cultures for the time being, especially as I have no chops in fundamental cheesemaking techniques as of yet, anyway. 

That said, lots of food for thought should I get inspired once again to go microlab.  Many thanks again, Linux.

[linuxboy]

It's the more practical approach, to try and use slurries and replicate the rind. On such a small scale, doing this type of isolation is much harder than stealing yeast.

No, paste is not affected much. Paste changes more with moisture level of curd and acidity.

[ArnaudForestier]

Just got back from an extended trip to the U.P., Linux.  Ate far too much, and mused further on this stuff...wanting to setup a good cave, and as soon as I do that, looking forward to trying out the rind slurry method.  Thanks again.

Paul