how to maintain wooden cheese vat

[Gene]

I make aged lactic curd goat cheese with raw milk from my own herd in upstate NY.  After reading about Mother Noella in Connecticut I was inspired to try using a wooden vat.  I do know that NY Ag and Markets would never let me use it if I intended to sell, but this is just for me and my friends.  I have ordered a used 58 gal oaken wine barrel from CA.  I intend to cut it in half at the bung and have two 20 gal vats.  How do I clean and maintain it between batches?  Rinse and scrub with plain water then drip dry?  Wash with vinegar?  I do not want to use harsh detergents as I do want to foster the interesting microflora.  Any ideas or ideas of other issues that may come up with this vat?  Thanks!

[Andrew Marshallsay]

Hi Gene
I hate to cast a damper on your idea but I think I can see a problem here from what I know of wood. Things like barrels and boats need to be kept wet so that the timber swells and seals the joints. I suspect that if you cut a barrel in half the shape of the staves will change and it will leak like a sieve.
I may be wrong. I hope I am. If I'm right though, you will have a couple of nice plant pots.

[Gene]

Good point.  If all goes well, I will be making a new batch every other day during the season.  I let the milk set for 24 hrs to ripen before ladling.  Hopefully that might be enough to keep the wood fibers saturated and swollen.  That still leaves the the question of off-season.  My hope is that filling it with water for a day or two at the start of the new season might work to rehydrated the fibers and make it useable again.  Or I could fill it with a heavy salt brine to carry it through the off season.  Here is a link to what I ordered: http://www.amazon.com/Wine-Barrel-Solid-Valley-Creations/dp/B004Q2AUTO?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

[Kern]

Frankly, I'd be very concerned about the build up of pathogens.  What you propose would never be allowed in a commercial cheese operation for the simple reason that it could never be thoroughly cleaned.  You say that you are not planning to sell any cheese that you make but that "this is just for me and my friends".  So, I take it that you believe that it is OK to subject your family and friends to the chance of death by listeria or other deadly pathogens but agree that you can't subject strangers because "I do know that NY Ag and Markets would never let me use it".  I hate to be harsh and nasty here but you are putting false esthetics ahead of safety and the outcome of doing this is never good.   

[Al Lewis]

Oak barrels are used to age whiskies and sherry.  They use them because there is an exchange between the charred oak and the liquor.  Scotch is aged in used Sherry barrels and takes part of it's taste from the sherry that soaked into the wood and the charred wood.  Whisky also gets its color from the oak barrels.  It is clear when distilled.  Not a good choice for making cheese.

[Gene]

Thanks Kern and Al for your input.  Kern, I know you mean well and sanitation is critical.  I would rather keep the focus of this thread to maintaining the wooden vat.  The issue you raise is much more complex and can be very divisive.  If you want to contact me offline I would be happy to point you to a few scientific studies that show wood is actually safer than stainless steel--sounds crazy doesn't it?  Al, what you say is true, but liquor, or wine in this case, is kept in the barrel for months and years at a time.  My milk will be there for 24 hours.

[Al Lewis]

24 hours each time and the whey will soak in each time.  I would suggest you take a look at the latest research on wooden shelving in cheese caves.  http://www.forbes.com/sites/gregorymcneal/2014/06/10/fda-backs-down-in-fight-over-aged-cheese/    You already know it's not safe for public sale as you stated earlier so if you don't mind risking your friend and families health then knock yourself out.  Seems you've already made your mind up and are just looking for someone to justify what you are planning on doing already.

[Gene]

Thanks Al for the input and your concern for my friends and family. You are right about the whey soaking in, that is exactly want I want and hope for.  I want to establish a diverse biofilm of bacteria that will go to work on my fresh milk to help colonize and acidify the milk.  As I mentioned earlier, while a worthy discussion, a debate of raw vs sterile is not the one I am asking about.  You are correct, my mind is made up on that score.  I realize that for some people sterile, dead food is the only way to have safe food.  I and many other people disagree. We are all covered head to toe , inside (GI tract) and out (skin) with microbes.  Without a thriving colony of "good" bacteria we would soon cease to thrive.  That is why people on antibiotics get diarrhea and start taking probiotics.

If anyone has ideas of how to promote a beneficial biofilm and maintain the wood, I would love to read your ideas.

[Kern]

Thanks Kern and Al for your input.  Kern, I know you mean well and sanitation is critical.  I would rather keep the focus of this thread to maintaining the wooden vat.  The issue you raise is much more complex and can be very divisive. 

Here's the problem:  You can't "sanitize" just for the bad bacteria.  You have to sanitize for all the bacteria or none of the bacterial at all.  Bad pathogenic bacterial (listeria, et al) thrive in protein rich environments.  That's why they are bad.  Our bodies contain lots of proteins just like whey contains proteins.  Aging wine or whiskey in oak barrels is very different simply because both contain an antiseptic (alcohol).  Wine obviously contains less.  Still it contains very little protein.  Finally, bad wine gives lots of warning:  In looks brown, smells and tastes like vinegar, will likely be cloudy, etc.  Cheese containing listeria provides for no warning at all.  You eat it, it can taste good, and several hours later you get very sick and if you are unlucky you die.

Since you can't sanitize your wooden vat without destroying the reason you want the vat in the first place, there is no way you can properly "maintain" your wooden vat.  It is as simple as this.  Case closed!

[SOSEATTLE]

For anyone who has Netflix, I would highly recommend watching their documentary series "Cooked". It is a series with 4 episodes based on the 4 elements (fire, water, air, earth) and incorporates the elements into food/cooking. They are all quite interesting and at times thought provoking. The "Earth" episode is about fermentation and includes discussion about cheese rind ecology and a good segment featuring the Cheese Nun and her wooden vat. Contrary to what you would think, potential pathogenic bacteria are much lower with her wooden vat than with a clean, sanitized stainless vat. She actually proved to the local regulators that the numbers of E. coli were much lower in the wooden vat than the stainless vat they wanted her to use. She has a PhD in microbiology so did this scientifically. She can now use the wooden vat to produce cheese commercially.


Susan

[Kern]

For anyone who has Netflix, I would highly recommend watching their documentary series "Cooked". It is a series with 4 episodes based on the 4 elements (fire, water, air, earth) and incorporates the elements into food/cooking. They are all quite interesting and at times thought provoking. The "Earth" episode is about fermentation and includes discussion about cheese rind ecology and a good segment featuring the Cheese Nun and her wooden vat. Contrary to what you would think, potential pathogenic bacteria are much lower with her wooden vat than with a clean, sanitized stainless vat. She actually proved to the local regulators that the numbers of E. coli were much lower in the wooden vat than the stainless vat they wanted her to use. She has a PhD in microbiology so did this scientifically. She can now use the wooden vat to produce cheese commercially.

What you post may well be true but this is not a discussion of wood versus steel.  Gene has stated that he wants to use a wooden barrel vat and let it develop its own bacterial flora.  I have simply pointed out that doing so may also result in growing harmful pathogens because you can't selectively sterilize any vat to kill only the harmful pathogens and preserve the beneficial bacterial.  I suspect that the Cheese Nun sterilizes to kill everything and recommend that Gene do the same if he wants to use his half barrel vat to make cheese.  I have not seen "Cooked" but I'll bet that the Cheese Nun does not use a wood vat with the nooks and crannies that one finds in a wooden staved barrel.  Pathogens can grow in these little voids as they are continuously damp and contain whey proteins.  Finally, I was referring specifically to Listeria - a pathogen with a much higher fatality rate than E. coli.

[Brochis]

Just because wood is porous doesn't make it less sanitary than glass, metal or plastic.  While I know of no research on cheese vats in particular, there have been several studies on the safety of wooden vs plastic/glass cutting boards.  Specifically, attention was paid to how bacteria hides in the cuts and crevices of used cutting boards.  This should be analogous to how bacteria might behave in a barrel.

Short version:  When Salmonella, Listeria and Escherichia coli were applied to wooden cutting boards, the bacteria died within three minutes while none died on the plastic cutting boards.  When incubated overnight at room temperature, no bacteria were found on the wooden cutting boards while the bacterial counts on plastic cutting boards actually increased.  Source:  http://www.nytimes.com/1993/02/10/health/wooden-cutting-boards-found-safer-than-plastic.html

It is unknown why the wood is so bactericidal.  While the porous nature of wood does allow some bacteria to penetrate below the surface, it is very difficult of the bacteria to ever be released again.  Washing the wood with a quaternary ammonium detergent (spray cleaner) preserves its antibacterial properties.  Plastic requires chlorine bleach.  Source:  https://news.ncsu.edu/2014/09/cutting-boards-food-safety/

Finally, the research page of the UC Davis Food Safety Lab concerning wooden cutting boards:  http://faculty.vetmed.ucdavis.edu/faculty/docliver/Research/cuttingboard.htm  Dean Cliver started this research project to see what kind of sterilization was needed to make wooden cutting boards as "almost as safe" as plastic ones, but it turns out wood was the best choice all along.  Quote from the above link:  "... we regard it as the best epidemiological evidence available to date that wooden cutting boards are not a hazard to human health, but plastic cutting boards may be."

Wash your wooden barrel with hot, soapy water and then let it dry thoroughly.  Yes, the barrel will shrink and you'll have to swell it again before it will hold water/whey next time, but there's little chance in anything bad carrying over.

One last quote from my favorite TV chef, Gareth Blackstock:  "That's what cheese is - gone-off milk with bugs and mold! That's why it tastes so good!"

Cheerio,

Brochis

[Brochis]

While I know of no research on cheese vats in particular, [snip]

That would be because I hadn't looked.  Turns out there is a recent article on wooden vats and cheesemaking, specifically looking for Listeria but also checking for E. coli, Salmonella enteritidis and Staphylococcus aureus.  It's from an open access journal so you can download the entire article and read it.  There's several nice pictures of cheese being made in the article.

I'll just post the abstract and conclusion here:

from Italian Journal of Food Safety 2015; volume 4:4509 no. 1 pages 36-39
http://www.ijfs.it/

direct article download:  http://www.pagepressjournals.org/index.php/ijfs/article/download/ijfs.2015.4509/4534

Characterisation of the microflora contaminating the wooden vats used for traditional Sicilian cheese production

Abstract
Traditional Sicilian cheese productions are carried out employing traditional wooden vats, called tina. Many studies have highlighted the beneficial role of wooden dairy equipment by contributing to enriching the milk microflora and improving the acidification processes. The present work was undertaken to evaluate the safety of the wooden vats used to coagulate milk. To this purpose, the different microbial populations hosted onto the internal surfaces of the vats used to produce two different stretched cheeses, namely Caciocavallo Palermitano and Vastedda della valle del Belìce DOP, were investigated for the presence of spoilage and pathogenic microorganisms as well as for bacteria with inhibitory effect in vitro against pathogenic microorganisms. A wide biodiversity of protechnological lactic acid bacteria (LAB), in terms of species, was revealed. Several LAB inhibited the growth of Listeria monocytogenes ATCC 7644. The wooden vats analysed resulted safe for three main findings: absence of the main pathogenic species, presence of high levels of LAB, anti-Listeria activity of many LAB.

Conclusion
The correct maintenance of wooden vats, as part of good manufacturing practices of the Caciocavallo Palermitano and the Vastedda della valle del Belìce DOP cheese production, promotes the selection of a microbial flora able to play an active role in the achievement of the food safety objectives through the biocompetitive activity of LAB and the inhibitory activity against pathogenic bacteria, particularly L. monocytogenes.


Cheerio,

Brochis

[Kern]

Brochis quotes one study done in Italy and then proposes that the results of this study can be made to be true everywhere.  Perhaps this study is universal and perhaps it is not.  But as stated above my argument does not concern wood versus steel (or plastic for that matter).  It is whether or not you can selectively sterilize a wooden barrel with likely openings between the staves so as to preserve the good bacteria and kill the bad.  I contend that this cannot be done with the assurance that all harmful bacterial are killed between each batch of cheese or over the extended period when the cheese is not being made.  But, set all my arguments aside and consider only this:  At best, using a wooden vat with its own micro-flora might arguably add some interesting character to a cheese that otherwise would not be present from the same cheese made in a SS vat.  At worst, the wood could contain deadly pathogens that could contaminate the cheese and bring injury or death to those who consume it.  So, the real question comes down to this:  In the normal course of cheese making what can be more reliably maintained to thwart the possible growth of pathogens - a porous wood vat or a SS vat? 

I doubt that you can find a microbiologist that will argue that the wood vat can more reliably be maintained than a SS vat.  So at what point does an arguably better tasting cheese justify a higher probability of sickness that could result in death?

[Gene]

Here is a link to an interesting book, chapters 5 and 8 are of particular interest for this discussion.  5 is co-authored by Sister Noella Marcellino who is also known as the "cheese nun".  A trained microbiologist, her research has shown that the wooden vat is actually safer than stainless steel in regards to pathogens, including Listeria.

Cheese and Microbes
https://issuu.com/quiasma/docs/1555815863