When Does Product Stop Absorbing Smoke, If At All?

[Chris Amirault]

In a number of topics around here, the following has been declared as (1) an opinion, (2) an empirical datum, (3) a scientific fact, or (4) a shibboleth:

Meats being smoked stop absorbing the compounds in smoke when they reach approximately 140F.

I've become curious about this declaration. I've made double-smoked bacon: does the ability of protein to absorb smoke compounds return when they are cooled? I've sampled burnt pork that "survived" a literal smoker meltdown that tasted of burned plastic, an event that occurred when the meat was well over 140F: do some compounds continue to be absorbed while others don't?

There are other questions that pop to mind. Do different proteins absorb at different rates? What about fats? Nuts? fruits? And who says, anyway? McGee has nothing to say about it that I can find, and everything else seems flimsy thus far.

Does anyone have access to actual data on this question?

[lancastermike]

That 140 number has been mentioned more times than I can count in various EG smoking topics. Were did it come from? Good Question. I always thought it came from the legendary EG smoking class by Klink. But a cursory glance at that just now reveals no mention of it.

I have zero data to back it up other than we have all pretty much used it. we could all be 100% wrong.

Perhaps some of the food scientists will show up here and beat us silly with data.

Edited July 1, 2009 by lancastermike (log)

[Chris Amirault]

It's not just on eG Forums. There are examples throughout the internet -- none, AFAIK, with references to back the claims up. It's the ether of the 'cue set.

[slkinsey]

Think about this: How could it possibly be true? Some smoked rib recipes call for pre-boiling the ribs before they even go in the smoker (taking the temperature well over 140F) and yet they turn out plenty smoky.

[Chris Amirault]

My point exactly. There are too many counter-examples for it to make sense. However, that's just an opinion.

No research out there?

[nickrey]

To broaden the discussion slightly, there is also a lot of talk about creating a pellicle on all foods prior to smoking to enhance smoke penetration.

When cooking my bacon, I smoke it at the same time without creating a pellicle. It is indirect cooking in a Weber BBQ but this process means that that the surface of the cured pork goes well above 140F (to get the desired core temperature). My bacon tastes very smoky despite two possible disadvantages (higher than 140F heat and no pellicle).

Can I add the pellicle question to Chris' temperature question? I can see its validity in cold smoking but cannot see where it would impact on warm/hot smoking when the surface of the meat is undergoing dramatic changes due to the cooking process.

[OliverB]

I've not read this, but I'd call it nonsense, as I've added just a tad of smoke towards the end of cooking with things that I took above 140.

Not that it really matters much, as most things will come off the bbq at or around that temp. But with chicken I've added a bit of smoke as a last minute thought and it worked.

Now, it might not penetrate as deep as the meat might be denser once it gets to 140? I don't know. One would have to set a smoker at 145, add some meat until it reaches that temp and then start the smoke, compare with a regular piece. If your smoker keeps it's temp at 145 or so for a long time, you might find a result of some sort.

But who would do that?

Seems an odd "scientific" fact to mention. Like "meat in a foundry vaporates". Yes, it does. Qickly. And?

:-)

[Chris Amirault]

I've not read this, but I'd call it nonsense, as I've added just a tad of smoke towards the end of cooking with things that I took above 140.

Not that it really matters much, as most things will come off the bbq at or around that temp.

←

Most low-n-slow barbecue comes off quite a bit after 140F. Pulled pork, for example, comes off above 200F.

[scubadoo97]

I've heard that meat will stop absorbing smoke at 140 due to the bark formation, pores closing up etc. not allowing the smoke to penetrate.

I'm skeptical

I've heard others on smoke foods forum say that the smoke ring stops forming at 140 but the meat will continue to take on more smoke as long as you give it.

This sounds more plausible.

[Chris Amirault]

Yeah, I'm afraid we've already debunked the smoke ring business over here.

[lancastermike]

Hey Chris

Yesterday was butt smoking day for me and in your honor I added a few chunks of wood when i re-fueled at 11 hours, which I have would usually not do. What the hell, wood is cheap and I got lots of it.

Not sure if it helped but it sure did not hurt. Man, smoked pork rocks.

[tim]

Hi,

I am aware of no scientific evidence or even a properly conducted comparison of smoking cold or hot meat.

Nevertheless, I have assumed that meat that is smoked cold will absorb more smoke flavor. When I smoke a steak right out of the refrigerator before searing, the resulting smoke flavor is always wonderful.

As a result, the reverse sear is my favorite method of cooking thick steaks and roasts.

Searing a steak before roasting with smoke adds flavor to the exterior of the steak, but it never has that same flavor as the cold smoked steak.

Is this my imagination? I think not.

Tim

[Chris Amirault]

I think that many of us have assumed that cold meat absorbs more smoke, but you know what they say about assumptions. As of this post, no one has presented any scientific basis for why 140F is the magic number -- or that there is one at all.

[OliverB]

Most low-n-slow barbecue comes off quite a bit after 140F. Pulled pork, for example, comes off above 200F.

←

true, but by that time it doesn't really matter if it still would take smoke? You usually start smoking pretty early or in the middle of the process, not just minutes before you get to that temp. At least that's what I do.

I can imagine that the crust (or what you want to call it) that forms will stop the smoke ring from expanding eventually, but that no smoke adheres to the food after 140 seems impossible. It might not penetrate, but I'd guess it still sticks to the outside and will taste just as smoky - unless one only eats the inner smoke ring. It might not absorb as well at 140 as before, but with any process that I've used or read about the smoke would have been going on for quite a while already, I've never read of anyone adding smoke at that temp. Possible I guess, people do all kinds of strange things :-D

I start the smoke either right away or after the initial searing over the hot zone.

[Chris Amirault]

I don't think anyone is suggesting that you put the meat in as you close in on 140F. However, many people suggest putting the meat in cold to start smoking and pulling it out of the smoke at 140F because "it won't absorb any more."

And, again, please see the above link. Smoke rings and smoke are two different things.

[Chris Hennes]

It turns out there is actually quite a lot of research on the topic due to the suspected relationship between aromatic hydrocarbons and certain types of cancer. I'm still digging through the literature, but as a starting point I used:

Simko, P. Determination of polycyclic aromatic hydrocarbons in smoked meat products and smoke flavouring food additives. Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences. Volume 770, Issues 1-2, 25 April 2002, Pages 3-18

Today, smoking technology uses mainly the special effects of various sensory active components (phenol derivates, carbonyls, organic acids and their esters, lactones, pyrazines, pyrols and furan derivates[13]) contained in smoke for aromatisation of meat products to make food with a specific organoleptic profile, widely demanded on the market. Smoke is generated by thermal pyrolysis of a certainkindof wood when there is limited access of oxygen. Temperature of smoke generally plays a very important role, because the amount of PAHs in smoke, formed during pyrolysis increases linearly with the smoking temperature within theinterval 400–1000C [14]. Direct exposition of meat products to smoke brings about higher concentrations of PAHs as compared to indirect methods, when PAHs are partially eliminated by condensation in tars [15]. Also, hot smoking used for treating, a main part of meat production, brings about higher concentrations of PAHs than cold smoking, used for fermented, thermally non-processed meat products [16,17]. Heavy or ‘wild’ smoking increases PAHs concentration to high levels [6,15,32,71,77]. In some types of products it is possible to decrease the concentration of PAHs by cooking[18]. Thehighest concentrationof PAHs in smoked products is immediatelyafter finishing smoking, then it decreases due to light decomposition and interaction with present compounds [19,20,72]. However, PAHs also penetrate into smoked products, where they are protected from light and oxygen, and after some time, the concentration stabilizes at a certain constant level [21].

While this doesn't directly address the question of the meat temperature, it does provide some useful references to sources which prepare the meat in a variety of ways and then measure the PAH levels. Updates as I read more...

[Chris Hennes]

An interesting data point:

Chen, B. H. and Lin, Y.S. Formation of Polycyclic Aromatic Hydrocarbons during Processing of Duck Meat. J. Agric. Food Chem., 1997, 45 (4), pp 1394–1403.

In this paper they assess a number of methods for cooking duck and the levels of PAHs that are formed in the process. It's an interesting data point because when smoking the breast, they chose to do so at 60°C, which is about 140°F. Unfortunately they do not give a reason for choosing this temperature, so it was probably selected as the target temperature for the duck. At this temperature, the amount of smoke absorbed by the duck continuously increased over the three hour smoke. No record was made of the actual meat temperature.

Time vs. total PAHs

30 min: 154.6 ppb

60 min: 174.5 ppb

90 min: 206.5 ppb

120 min: 317.6 ppb

150 min: --

180 min: 526.8 ppb

[Chris Amirault]

Is the duck meat at 140F or the smoking chamber temp 140F?

[lancastermike]

Chris H.

Better you than me. I just make the smoke put the meat on and eat it. Way, way over the head of this old political science major.

[Chris Hennes]

Is the duck meat at 140F or the smoking chamber temp 140F?

←

The chamber temp: they do not record the temp of the meat (a common theme in these experiments, it turns out).