Bacteria Safety Help

gotbbq · March 05, 2005, 12:11:05 PM

I know i saw a post somewhere about bacteria etc, how long is the accepted time to leave a pork butt out of the fridge to get to room temp before putting it into the bs. I don't want to kill my guests, most of them anyway[:D]

gotbbq

Habanero Smoker · March 05, 2005, 02:42:54 PM

I pull my meat out of the refrigerate one hour before I place it in a preheated smoker. As a general rule, do not leave it in the danger zone (40 - 140 degrees F) for more than two hours. There are exceptions to this rule - I forgot the exact temperature range, I believe it's between 90 - 110 degrees, that is the optimal condition for most bacteria to grow; therefore you need to reduce the time food is exposed in those temperatures.

Oldman · March 05, 2005, 03:34:57 PM

Well when I go to do a large piece of meat I allow it to go to room temp. (70-72 F) I've never had a problem. Of course I made sure the meat was not in question--like being almost to old!

Olds

http://rminor.com

Chez Bubba · March 06, 2005, 04:15:51 AM

Calling JJC.....Is there really a "danger zone" if you cook it to 190F? Won't that type of heat cook off the potential boogies?

Kirk

http://www.chezbubba.com
Ya think next time I check into a hotel & they ask "Smoking or Non?" they would mind?

manxman · March 07, 2005, 10:31:11 AM

Hi Folks,

At the risk of stealing JJC's thunder I have had a chat with a Chartered Scientist in our Microbiology Department. (I work in a Pathology Department tho. Microbiology is not my area of expertise)

I have also had a look through one of their Reference Books: Food Poisoning and Food Hygiene: Sixth Edition: Hobbs and Roberts)

The following information may be of help:

*Pathogenic (harmful) bacteria grow best in the temperature range 15 - 45C (59 - 113F) except one nasty which grows well up to 47C (117F)
*Bacteria divide every 15 - 30 minutes at optimum temp.(37C/98.6F)
*Bacteria grow slowly at 45 - 50C (122F), but growth rate falls rapidly above 45C (113F)
* Only a few can grow at >50C. (122F)
* Non sporing cells of food poisoning bacteria are killed at temps >60C (140F) after exposure for 10 - 30 minutes or more at that temp, dependant on type. The longer the exposure the higher the degree of destruction.
* <15C (59F) grow at reduced rate.
* <7C (45F) cease to multiply but do not die.
* extreme cold does not kill all bacteria.
* when cooling cooked meat cool to less than 7C (45F) within 1.5 hours.
* food poisoning occurs when large numbers of bacteria (or spores) survive, either directly or indirectly (toxin production)
* Bacteria that cause food poisoning will be invisible, the appearance, smell and taste of the food is generally unaltered.
* Smoking will only preserve the outside of the meat, not internally.
* Meats that are rolled (e.g brisket) carry additional risk, may be contaminated by handling then contamination rolled to cente of joint and internal temperature does not meet that required to kill contamination.

Just a last thought, if you think of a single bacteria at time zero, under optimum condition 7 hours later you will have 2,097,152 of the little blighters. But at two hours at optimim temperature only 64, this is based on them doubling every 20 minutes!

Hope this is of some help!

Manxman.

Habanero Smoker · March 07, 2005, 11:11:59 AM

Maximan;

Good information.

Just want to add that some types of food borne bacteria produce spores and toxins that survive the high temperatures of cooking. If these types of bacteria exist is sufficient numbers prior to cooking, it doesn't matter if you cook the meat to an internal temperature of 190 degrees F., you can become ill due to improper handling of food prior to cooking.

I have to find the source that I referred to in my earlier post - "are exceptions to this rule - I forgot the exact temperature range, I believe it's between 90 - 110 degrees, that is the optimal condition for most bacteria to grow;"

manxman · March 07, 2005, 11:48:22 AM

Hi Habanero Smoker,

Very true, some spores can be boiled for hours and will survice, there are exceptions to every rule. The main thing is to keep the bacteria concentration low by adhering to optimum processing conditions so there are not enough to cause poisoning.

The optimum temperature for bacterial growth is 37C or 98.6F, normal human body temperature. (there's a coincidence!)

Much of the information I posted will be old hat to the more experienced member but some of the newer ones may benefit.

Basic hygiene will sort most issues such as washing hands thoroughly or wearing disposable gloves when applying rubs, keeping all equipment clean and avoiding cross contamination (e.g raw meat to cooked meat.

Getting meat from a reputable source, bringing meat to room temperature (particularly in hot ambient temperatures climes) for the least amount of time possible, cooling rapidly post cooking and monitoring during the cooking process will sort the vast majority of issue - most of it is just a common sense approach.

The majority of the examples quoted in the book I had a look are failures in this common sense approach, examples include failure to wash hands after coming out of the toilet, leaving cooked food overnight at room temperature because there was no room in the refridgerator, using very large pieces of meat and cross contamination.

Occasionally people can be just plain unlucky due to circumstances beyond their control but most are within our control, however how many people have made themselves ill using a B.S, very few I suspect.

Something we need to be aware of and have a bit of basic knowledge but in most instances it will be (or become) second nature.

One or two nasty's that thrive without oxygen such as botulism, something I need to be aware of now I am getting a vacuum sealer!!!

Manxman.

JJC · March 08, 2005, 02:26:39 AM

Hi Manx and Habanero,

Both of you are spot-on with your advice. Sorry I couldn't chime in sooner, but we're on the middle of a busy stretch at work right now and I'm trying to get everything squared away before I take a much anticipated vacation!

Most sources extend the "danger zone" all the way to 140F, rather than 117 or 122F, to cover that last 1-2% of possible bacteria. If you look at the Curing and Brining piece in Olds' FAQ board it will have very similar info what MM is stating. Nothing ilustrates the reason for keeping food out of the danger zone than Manx' 2hr vs. 7hr. scenario!

P.S. to Manxman--what do you do in the Path Dept.? I have many fond memories of Pathology . . . of course, the problem with pathologists is that they know everything, only it's too late . . .

John
Newton MA

jaeger · March 08, 2005, 02:40:28 AM

<blockquote id="quote">quote:<hr height="1" noshade id="quote">One or two nasty's that thrive without oxygen such as botulism, something I need to be aware of now I am getting a vacuum sealer!!!
<hr height="1" noshade id="quote"></blockquote id="quote">

The danger with these bugs is not that it will make you sick, it will kill you! Good sanitation and food handling a must!!!

Doug

JJC · March 08, 2005, 02:41:01 AM

Manxman,

Congrats on your new star! [:D]

John
Newton MA

Oldman · March 08, 2005, 02:59:24 AM

Manxman,
I E-mailed you concern this information. Have your recieved it?
<blockquote id="quote">quote:<hr height="1" noshade id="quote">. . . of course, the problem with pathologisdts is that they know everything, only it's too late . . .
<hr height="1" noshade id="quote"></blockquote id="quote">
EDIT Now JJC I thought we talked about you being nice to folks... [^]
Olds

http://rminor.com

manxman · March 08, 2005, 09:32:20 AM

Hi JJC and Oldman,

JJC.... Haematology is my area, did about 6 months Microbiology during my training many years ago but it never really interested me the way Haematology does.

Consequently, all of our patients are still in the land of the living! (at least for the timebeing![;)]) Having nothing to do with the morbid anatomy side of the laboratory.

Where are you off to on vacation?

Oldman.... not had a chance to look at my home emails recently but will have the opportunity to check them this evening, will get back to you on that one. [:)]

cheers folks,

Manxman.

Habanero Smoker · March 08, 2005, 10:51:49 AM

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JJC
 
I have many fond memories of Pathology . . . of course, the problem with pathologisdts is that they know everything, only it's too late . . .

John
Newton MA
<hr height="1" noshade id="quote"></blockquote id="quote">
John,
I have to remember this one. You never know when this joke may come in handy!

mamba · March 08, 2005, 01:00:24 PM

Hey guys. Can we go back to Kirk's question? If you cook something to 190, won't it kill anything in the meat regardless of how much of it is in there? Did I miss something?

manxman · March 08, 2005, 02:40:51 PM

Hi Mamba,

<blockquote id="quote">quote:<hr height="1" noshade id="quote">
Non sporing cells of food poisoning bacteria are killed at temps >60C (140F) after exposure for 10 - 30 minutes or more at that temp, dependant on type. The longer the exposure the higher the degree of destruction. <hr height="1" noshade id="quote"></blockquote id="quote">

The answer to Chez's original question is that in most instances.... yes!

However there are always exceptions (e.g spores)as science is rarely black and white, there are always exceptions to the rule! What I was trying to impart was that the cooking is only one part, albeit a very important part, of a bigger picture.

I did'nt want anyone to take any reply out of context.

Experiments have shown that slow low temp cooking holds no greater hazard than convential cooking providing manufacturers instructions are followed and all aspects of the process controlled.

Manxman.