Greetings from Vermont

[Pam@doehillfarm]

Hello All,

My name is Pam and I live in Vermont.  My husband and I operate a small dairy goat farm and are vendors at our local farmers' market selling produce, goat's milk soap and milk-fed Berkshire pork.

I started working with cheese about five years ago, first starting out with the simple, yet quintessential goat cheese, chevre.  However, within the last few years, I've set my sights on the cheeses I truly love which are the ripened cheeses such as brie and camembert.  I've learned to relax and enjoy the process which, in turn, has helped to produce some really nice cheese.  It's my hope that within the next three - four years, that I'll be able to set up a small artisanal cheese operation on the farm. 

I've used this forum in the past to search for answers to many of my questions and I figured it's about time I become a member.  My next cheese will be my most favorite of them all - commonly referred to as "stinky cheese." However, I'm unable to locate much information on working with washed rind cheese and it'd be good to have you all as a sounding board to help me through this process. 

Because I work with raw milk, listeria is a major concern for me as  the literature I've been able to get my hands on has scared the be-jeebers out of me.

I'm currently in the process of researching "protective cultures" and would love any opinions or insights as to their effectiveness.  I see Danlac sells Holdbac Listeria and the Holdbac literature indicates that it virtually eradicates the threat of listeria; however, additional research contradicts their claim and indicates that it's effectiveness is short lived.

I look forward to hearing from those who'd like to comment.

Have a great day!

Pam

[linuxboy]

Pam, there are three ways to go, and not much middle ground.

One: complex balanced ecosystem where known proteolytic bacteria such as b linens and s xylosum actively work to produce enzymes that lyse listeria to ensure safety. This control method is used heavily in many classic European cheeses that rely on complex morge washes that are adapted and self-select for listeria prevention

Two: Complex, engineered system where you use adjuncts and meticulous cleaning in addition to testing as part of your HACCP to prevent listeria.

Three: Hybrid, for those who are ultra paranoid, or when required by law... Uses old-world techniques with some new-world approaches, such as steaming wood boards.

The Holdbac line does NOT eliminate listeria. More so, it's a helpful preventative measure for when working with milk contaminated with listeria. That is only a small contamination vector and honestly, your least likely one. Just about all raw milk cheesemakers I know are ultra clean and their TPCs and SCCs are low. You are far more likely to see contamination through improper brine management, morge contamination, poor sanitation, affinage issues, etc. Meaning contamination post make. If you are 10 days into a morge wash and your morge is bad, you will have post-make contamination.

There's so much information in my head from years of research and practice on stinkies... would really help me if you could ask questions. Having trouble focusing my thoughts.

[Sailor Con Queso]

Listeria is almost always an environmental contamination, not from the milk itself, so raw milk does not necessarily pose a bigger threat than pasteurized. Unfortunately, Listeria likes moist environments and is a MUCH bigger threat with soft cheeses, like your Brie and Camembert. But that also means that you will have to use pasteurized milk for fresh cheeses anyway unless you intend to age past the 60 day FDA rule. Then the Catch 22 is that past 60 days, soft cheeses are actually at higher risk for Listeria. In fact, in France they can't sell an AOC Camembert past 59 days because the risk is considered to be so great. In the USA, the FDA has been conducting Listeria testing particularly at soft cheese facilities. They have found Listeria in over 31 percent of the facilities tested, but, those were environmental findings, NOT in the finished cheeses. So the key is cleanliness. Keep in mind that Listeria can create a biofilm capsule that makes it very difficult to kill with normal sanitizers. Use bleach in questionable problem areas instead of StarSan for example.

FYI, according to Catherine Donnelly, microbiology professor at the Vermont Institute for Artisan Cheese, there are certain cheeses that simply won't support the growth of Listeria. In particular, hard Italian cheeses, Swiss types, and Cheddars. I have not researched this enough yet to tell you why.

[ArnaudForestier]

Pam, I just wanted to say welcome.  I used to live in Londonderry, and loved your state, one of the best periods of my life.  And as a chef, I used Berkshire pork exclusively, cooked it many ways, find it unbelievably good.  Good luck to you.

Linuxboy as usual has given wonderful advice.  What research I undertook on the same question steered me towards his option 1, but I acknowledge it's a difficult decision. (And commercially, admittedly, the field of play is often circumscribed).

edit:  whoops, see that Sailor's post and mine crossed in the mail.  These two gents are powerhouses of expertise....thanks as usual, from my intruder's perspective!

[Sailor Con Queso]

FYI, according to Catherine Donnelly, microbiology professor at the Vermont Institute for Artisan Cheese, there are certain cheeses that simply won't support the growth of Listeria. In particular, hard Italian cheeses, Swiss types, and Cheddars. I have not researched this enough yet to tell you why.

I have just spoken with Catherine Donnelly regarding these cheeses. As I suspected those cheeses are considered safe because of very low moisture content, low pH, salt content, or high cooking temperatures over an extended time (like Swiss), or a combination of these factors. She does consider direct salted cheeses, like Stilton, to be equaly safe, even though it is a very moist cheese.

[linuxboy]

there are certain cheeses that simply won't support the growth of Listeria. In particular, hard Italian cheeses, Swiss types, and Cheddars. I have not researched this enough yet to tell you why.

Multiple factors. For italian types, bacteriocin production by bacilli, especially in whey starter systems. The abuse those bacilli take is enormous, so whey systems self-select for strains that survive extreme conditions and resist phage and kill competitors. Often, they include bacilli like rhamnosus, same as Holdbac.

For Swiss types, propionate is an inhibitor. Alpine types, roughly similar to italian types (they're really cousins, so no surprise there)

For cheddars, it is pH as well as length of maturation.

For all of them, the paste MFFB is not conducive, and more importantly, surface Aw is not conducive to Listeria. So post-make contamination is minimized because listeria can't gain a foothold.

What research I undertook on the same question steered me towards his option 1,

Personally, I think it is either option 1 or option 2. Both are systems that work. You're either "dirty" and create natural ecosystems that you control organically, or you're "clean" and expand effort to keep things pristine. When you go to a middle ground, it's hard to pick and choose and create an arbitrary new system because you're mashing organic controls with modern microbiological controls. Two incompatible philosophies. But, it's possible, with an in-depth understanding, especially when the Man forces you to make changes that are contrary to traditional wisdom.

[linuxboy]

Catherine is spot on IMHO (humbly). Stilton I agree with because of pH at mold, length of aging, and rapidity of surface flora development, and flora mix (as opposed to cam flora). Not because of salt, though. It's a case-by-case evaluation  for each cheese because listeria inhibition depends on the overall make process and the control points possible at each step. I can make you a milled curd, salted cheese susceptible to post-make contamination, for example. Would have to work a bit of effort in, though, not intuitive.

[Sailor Con Queso]

LB - I have read in a couple of places that it is possible to add a little Propionic as a natural Listeria inhibitor. That of course will also change the flavor profile.

Holdbac comes in 4 variations. One is actually called Holdbac Listeria. Danlac only claims that the Listera version, which contains Lactobacillus plantarum, inhibits Listeria. And Dairy Connection for example does not even list the Holdbac Listeria version.

[linuxboy]

possible to add a little Propionic as a natural Listeria inhibitor.

Yep, totally agree. Also, possible to select strains without affecting flavor profile drastically.

Danlac only claims that the Listera version, which contains Lactobacillus plantarum, inhibits Listeria

They can claim whatever they want for product differentiation and marketing purposes, doesn't make the science any different. If I take rhamonosus that produces gram+ bacteriocins... guess what... it will inhibit listeria. What they likely mean is that in studies, the plantarum strain they have has been more effective than other strains or other species, so of course let's use the best strain and species we have for specific applications (coliform, listeria, etc).

But yeah, we're still talking about paste/milk issues. Wouldn't do an extreme much for morge contamination. You could inoculate the morge with plantarum or rhamnosus or similar, but why do that when it's easier to rely on proteolytic compounds by linens and the like.

[ArnaudForestier]

Personally, I think it is either option 1 or option 2. Both are systems that work. You're either "dirty" and create natural ecosystems that you control organically, or you're "clean" and expand effort to keep things pristine.

Pav, totally agree.  Sorry, folks, if I've mentioned this already, but it seems apropos to the discussion.  Working for a regional brewery in the Midwest U.S., bottom line, option 2.  Each production run of 100 bbls of beer received 19 HAACP points of microbiological and other QC assays, along the chain.  Once brewed, the wort and beer never again saw the light of day - everything in a closed loop system, everything rigorously CIPed, etc.  Desire for, and result was "clean" beer.

On a brewery tour of England.  Couldn't be more Option 1, and I loved it.  Yeast dragged across a converted mechanic's garage in more-or-less cleaned 5 gallon buckets, then pitched into open fermentors, completely exposed to the ambient air.  But then, these yeasts have been mothered from at least a century and a half of indigenous strains, and were considered more or less "pac-men" among flora, capable of out-competing anything undesired, and wonderfully suited to the ales this house makes. 

Both work, admirably, in my opinion.  My bent since making cheese, and with the help of people like yourself, Pav, and Sailor, Francois, many others, has been to trust more and more in nature herself to yield the desired fruits.

[Pam@doehillfarm]

Hello back to everyone who replied!

I have to say that I belong to several groups and I've never been more warmly welcomed or had my posts addressed so thoroughly.  This is all welcomed information and I'm anxious to start asking questions as I've obviously come to the right place to get the answers. Many thanks!

Will pasteurizing help much to close the margin of risk?  I understand from what I've read and from what's posted already that it's not the milk so much that's at risk of listeria contaimination for me, but the cheese's subsequent treatment.  Would pasteurizing help create a rind that isn't so hospitable to undesirable bacteria? 

Actually, I've never really made cheese from pasteurized milk.  I will, however, use pasteurized cream ocassionally and I don't really notice the difference when I include it.  Possibly my palate is still in the novice stage and doesn't recognize the difference.

My animals are healthy and have low SCC, so that's a plus.  I immediately strain and chill the milk within 20 minutes of milking.  I sterilize my equipment and cheese fridge with the same detergents/sanitizers that I use and are approved for milking equipment, first with a chlorinated cleaner and then with an acid-based C.I.P. sanitizer (peroxyacetic acid + hydrogen peroxide).  So, my sterilizing methods are, I think, rather steller.  I don't use wood, only food grade plastic or stainless steel.

So, there's the good part.  Now here comes the bad...I process the cheese in my house...a 250 y/o VT farmhouse. (Oh, and if anyone's looking to buy...I'm looking to sell.  I'd like to go back north and relocate to Isle La Motte (I'm sure Arnaud knows where that is ) I miss my Canadian relatives.

So, I'm sure I have a whole platoon of adverse environmental factors attacking and degrading the quality of my milk that I work hard to achieve while in liquid form.

I've ordered the PLA blend from Danlac as I knew I needed the b linens and I use the geo in my camemberts/bries anyways, so it was great to already have it in the blend. 

I've already asked if it might improve my chances of non-contamination if I pasteurize...

What about the brine mixture?  What if I used a clean brine each time?  I've read that the repeated use of the brine imparts more character into the brine making it more desirable with each use.  However, if I made a clean brine each time, I should reduce the risk of listera another notch...right? 

I'm also curious to add a liqueur to the brine such as a grape brandy or a walnut brandy I've been reading  about.  Will adding a fruit liqueur heighten or reduce my risk of contamination or not make a difference?

And, when making the brine, it would make sense to me to boil/sterilize the water prior to inoculating the prepared brine.  Am I on track or did I derail that assumption?

Sorry, I'm trying not to ramble.  There's just so much to say and ask.

Linuxboy makes mention of Europeans using a "...complex morge wash..."  Is that a wash that can be obtained or approximated by a combination of yeasts/molds, etc, that can be purchased here in the U.S.? 

Ok, I'll give you all a break...for a moment. 

Pam

[linuxboy]

First method requires a great deal more finesse and mastery. Anyone can do routine QC by the book. It takes years of failure to do well at listening to cheese and being in tune with what it wants. I hope to in another 5 years release my stinky semi-lactic raw milk goat rounds made with captured morge. Sounds appetizing, eh? And I've been working on them for half a decade. Thankfully, I have lots of failure under my belt

[linuxboy]

I have to say that I belong to several groups and I've never been more warmly welcomed or had my posts addressed so thoroughly.

Yay! Welcome . You get what you pay for. Wait, what?

Would pasteurizing help create a rind that isn't so hospitable to undesirable bacteria? 

No, not based on science. Rind development is unrelated to pasteurization. What pasteurization will do is subject you to less scrutiny from the FDA.

peroxyacetic acid + hydrogen peroxide

nice.

I've read that the repeated use of the brine imparts more character into the brine making it more desirable with each use.  However, if I made a clean brine each time, I should reduce the risk of listera another notch...right? 

Maybe. You have to think about listeria in terms of contamination vectors. Say you mix up a batch, but the tub was contaminated. Brine is gone. Or say you have listeria hiding behind a fan or in your air coming from the blower. Same, it's an environmental issue. It's far easier to re-use the brine and keep it saturated, and also add a little bleach (don't quote me, but IIRC, 50-80 ppm) to the brine. So you don't necessarily have to mix up a new batch each time.

Will adding a fruit liqueur heighten or reduce my risk of contamination or not make a difference?

Heighten, if there's sugar in it. But, why would you do this? If you want to infuse the flavor, soak the cheese in it. In brine, it will impart almost no flavor. Too weak.

it would make sense to me to boil/sterilize the water prior to inoculating the prepared brine.  Am I on track or did I derail that assumption?

Yep, also use saturated. Listeria survives 22%, sometimes higher.

Is that a wash that can be obtained or approximated by a combination of yeasts/molds, etc, that can be purchased here in the U.S.? 

Yes, but it is tough. Proper morges will have dozens of proteolytic strains of linens, with multiple strains responsible for killing listeria. You can kickstart a good morge with commercial variants, but it's not the same. Easier way would be to take a European cheese with a rind that used a morge known for having anti-listeria properties, and propagate it forward, and then add your blend until it stabilizes. Or capture wild strains. Or go to Europe and beg/borrow/steal some. Doing it properly is kind of the holy grail of cheesemaking. You need a good deal of biochem knowledge and cheesemaking knowledge, and luck. And if you live with someone and/or have limited space, a VERY understanding and patient partner. "That's just the morge in the detached garage, 50 ft away, honey". "No, it's supposed to be like that".

[Pam@doehillfarm]

Should I invest in a salometer? 

And, can anyone recommend a reasonably priced PH tester?  I realize that if I'm going to battle covert and potentially deadly pathogens in my washed rind venture, I should probably go in armed. lol

Thanks all!

Pam

[linuxboy]

Um, you can saturate without a salometer. Make a saturated brine to begin with, and then after that make sure there's always bits of salt crystal on the bottom of the salt tank. And top it off from time to time. Salometer is helpful, though, for quality control assurance.

You don't need a pH meter for dealing with potential pathogens. You need lab tests to verify. But a meter helps with consistency. Try the extech, when it works well, it's decent and cheap.