cure meat safely at home


 
I started reading Matt's blog after an internet search for "bresaola" pointed me his way. It was at the time he was attempting his first dry cure project. He's come a long way since then. A lot further than I have, I'm finally attempting my first bresaola as I type.

dang! I search his blog its been 3 yearssince I read that. man, I've been slacking.
 
Really enjoy Matt. One more that is an absolute is Cured Meats, Jason constantly has adventurous projects going and is a wealth of knowledge.
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">man, I've been slacking. </div></BLOCKQUOTE>
Likewise... I really need to resolve my curing chamber before venturing too much further. Perhaps I'll get another bresaola in before the basement warms up.
 
I'm a little disappointed in the article. I asked for a reference to one of the safety facts listed in the article. I didn't get a reply to my comment so I emailed Matt. He was nice enough to exchange a few emails, but he never explained where he got his info other than "it's commonly accepted."

so does anyone know why you need to dry to 65% of your original mass? I did some math regarding water activity and it doesn't seem like there's a realistic cut off at any point.
 
I didn't do the math but there would have to be a point where the water activity is such to prevent pathogen outgrowth, if we're talking dry-cured meats and sausage.
 
Have you checked out Len Poli's pages. While he doesn't provide the specific reseach as Kevin pointed out the drying is to create an environment that inhibits bacteria growth.

He does have alot of good information and recipes that he himself developed and tested. By the way he works in the Sausage making industry

http://home.pacbell.net/lpoli/index.htm

Brad.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> I didn't do the math but there would have to be a point where the water activity is such to prevent pathogen outgrowth, if we're talking dry-cured meats and sausage. </div></BLOCKQUOTE>

here's what I sent Matt:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Marianski states that fresh meat has a water activity of 99% which can be reduced to 96-98% with the addition of salt.

I've read varying reports that suggest the water content of lean muscle is around 70% and fat around 30%.


100 g all lean = 30 g protein, 70 g water which can be further divided into 67.2 g free water and 2.8 g bound water (96% aw)

the meat is hung until it loses 35% of its original mass, so it loses 35 g of free water

so now we have 65 g = 30 g protein, 35 g of free water and 2.8 g bound water

2.8 / 35 = 8% or 92% aw

Lets assume the sausage is 1/3 fat

100 g = 66 g lean ( 46.2 g water) 33 g fat (9.9 g water) total 56.1 g water (53.8 g free 2.2 g bound)

65 g = 43.9 g lean/fat, 21.1g water

2.2 / 21.1 = 10% or 90% aw


This number matches actual measured aw in Belgian meat products. The study (I can forward you the link if you want) reports 'salami' type sausage 92%, semi dried sausage at 92%, full dried sausage at 88%, 'chorizo' type at 90%.

the only thing that lives below 92% aw is Staph. aureus. </div></BLOCKQUOTE>

USDA recommends a water activity below 85% to be considered safe. I just don't see how that's reasonable (given my math is correct). We know that reducing water activity is one component of safety, along with salinity and pH, and it seems like if you can get 91% aW, you have most bacteria under control. Taking all that into consideration, it doesn't seem like there's a magic number, and if there is, it seems like 35% wouldn't be it (its not low enough to be 100% safe and 30% would probably be sufficient).
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">USDA recommends a water activity below 85% to be considered safe. </div></BLOCKQUOTE>
If they do this would be moot. (It sounds a bit like their simplified dumbed-down info they proffer to consumers rather than their info for pros.

When dealing with pathogens on an HACCP level, it's the combination of results - pH, aw, etc. - and the process getting there - the procedures used in making the sausage, e.g., the cleanliness during its making, ingredients used, temp of ingredient during processing, temp post processing, etc.

Aw < 92 in one way to deal with most common fb pathogens - Clostridia spp, Listeria. Vibrio, Salmonella, Campylobacter. S. aureus does require a much lower aw, but that's only one control. S. aureus does not compete well with spoilage bacteria (which is why it is less of a concern on raw foods, much more on cooked foods, especially those that are handled after cooking - like meats turned into salads, pulled pork, et al.) and needs sufficient time at sufficient temps to outgrow till the point sufficient numbers are reached. It is at that point toxin is produced.
 
But I'm still not clear if 35% is a magic number.

It seems like around that number is good, but more or less works too.
 
I think to be determinate you'd have to do the math, including any non-meat, water-containing ingredients as well. Or know what the specifics are of the other controls employed.
 
imo/ You can't generalize and say that an x amount of weight loss makes something safe. As Kevin notes there are many factors involved and I think they are somewhat unique to each recipe and to each batch. Calculating the optimum point, even given a desired goal, would be difficult, at best, without the ability to do a fairly in-depth analysis of each attempt.
Moisture content alone is not the sole factor to "safety".
That said: For most of what "we" do, a 30 to 40 percent loss in drying does seem to land a desirable texture in the final product. That (my guess) still leaves too much moisture in the final product if drying was the sole method in play. However, the addition of salt &/or nitrates/nitrites and an altering of pH all contribute.
 
by & by: J, great question and hope we can find a more definitive answer!
By the some token, to the best of my knowledge, nether Matt or Jason, are food scientist.
However if one follows their advice (as well as common sense) one will probably have a fairly positive & successful end result.
My inquiry to Michael Ruhlman for his drastic change in, blog versus book recommendations in brine
strength were met with a similar inability to provide a sufficient (ie/show me some science) explanation.
 
I'm certainly not a food scientist, but from what i've read the safety of the salame is given by a combination of things. Salt, cure, pH and aW.

The first thing to remember is that aW is a measure of the "available" water for bacteria, which i do not believe is necessarily the same the actual amount of water in the meat based on math. That water could be bound in the protein structure and not available for bacterial growth. If you want to measure the aW of your cured meat, without spending $300 on an aW meter, i've been told you can come close by closing the meat in an enclosed tupperware with a hygrometer. After the system equilibrates the hygrometer will read the aW of the meat in the box.

Also, the minimum values for aW for bacterial control, i believe, are based only on the use of aW, and don't count the use of salt, other bacteria to lower pH or curing salt (which have been shown to slow decay as well as inhibit botulism).

The use of 30-40% loss in the final product, as Marc points out, is more of a texture thing than a safety thing, but as you point out, it does seem rather cavalier. 35% isn't a magic number as the aW will change based on fat content as well as the grind size i think.
 
It is always a combination of protocols. Some cured/preserved items rely virtually on salt alone - a rather high concentration at that (fish, some preserved meats, especially in days of yore); some on fairly high salt, cool temps, possibly smoke (country hams); some, salt and drying (like jerky) - and so forth.

Dry-cured sausage is no different.
 
Do you guys think 47-50F/8-10C is warm enough to air-dry salumi? My wine cooler runs humidity constant at 70% at those temperatures, but it's about 10 degrees F cooler than the 60F I see recommended as optimal.

Just got my first few projects hanging in there, I had some fuzzy molds on a pancetta but imo that was due to several factors: because I hung it up poorly, and thought that it would be fine unplugged in my 58F garage. Not running the compressor caused dead air space and the humidity spiked to 90 with the door closed a couple times. The molds came off with vinegar of course.
 
funnily enough, just this morning i read about a chef who has to run his curing chamber at 40 deg, but he keeps RH at about 78-80%.
Remember that the cooler the air, the less water is held at a certain RH.

So 55 deg. and 75% RH has more water in the air than 50 deg. and 75% RH.

So if you're going to run at 47-50, i suggest bumping the humidity to 75-80%.
 
haha, I guess it was too good to be true that it ran constant 70% out of the (craigslist) box.

Seems to be working fine for whole muscles but I definitely don't want to ruin any salumi. Thanks, Jason.
 
Yeah I think the culatello is some months down the road for me
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