12. Science and barbecue
--------------------
[Is it dangerous to your health to eat barbecue due to the presence of carcinogens in
the meat caused by the wood fire?]
Smoky Hale--
Found this on the Kansas City BBQ Forum and it seems to answer your question.
Nitrosomines, which may be produced in charred fat of certain animals, has tentatively
and tenuously been linked to cancer in humans. In order for nitrosamines to be created,
there must be very high temperatures (500F+) and charring. Minute quantities may,
therefore, be created by careless trimming of the fat on steaks to be broiled (500-700F)
and overcooked or flamed. The risk of getting cancer from this is less than drowning in
the shower, IMHO.
Barbecuing is, by definition, cooked at temperatures around the boiling point of water
and no competent barbecuer is likely to willingly let his meat reach the point of
charring. The 'burnt ends' served by some commercial establishments are not barbecued and
are more of an affront to good taste than a threat to health. If cooking meat over hot
coals were a hazard to human health, the species would have starved or died out a couple
million years ago. I think this is a rumor started by a vegetarian who used to be a
Women's Magazine Food Editor and therefore knew nothing about barbecue. Cook slow, relax,
have fun, and don't worry.
-------------------
[There was a long discussion on the List about "Fluid's Affects On Heat
Transfer" in a barbecue smoker. It was way over my head. Can somebody summarize this
for me?]
Jim Prather--
I wrote that post. Let's review heat transfer.
When you hold your hand close to a light bulb, you can feel heat being transferred to
your hand. This is RADIATION.
Guys, when your sweet thing blows her hot breath into your ear, you feel heat being
transferred to your ear. This is CONVECTION.
When you put your cold feet against that sweet thing's warm body, you feel heat being
transferred to your feet. This is CONDUCTION.
Here is a simplified version of the Fluid's Affects On Heat Transfer dissertation. In
it was compared a cooker to a glass of Scotch with an ice cube in it. What happens is that
the surrounding Scotch transfers heat to the ice cube. This can be compared to the air in
a cooker transferring heat to the enclosed meat.
The ice cube's outside surface undergoes a change of state. It is from a Solid to a
Liquid. In a comparable way, in our cooker, meat loses moisture by evaporation. Also a
change of state. It is from a Liquid to a Gas.
This takes place slowly in a cooker. Heat transfer to meat is by CONVECTION in a
cooker. The air is cooled by the meat as the air passes by and exits the cooker. The meat
receives BTUs from the passing air and its temperature rises.
The outer surface of the meat is hotter than the inside of the meat. The heat transfer
inside the meat is by CONDUCTION. To reduce somewhat the higher temperature of the outside
of the meat, moisture can be added to the outside by the chef person. This cools the
outside by evaporation, which is still hotter than the inside of the meat. The inside of
the meat continues to cook.
This adding moisture to the outside of the meat by the chef person does not add
moisture to the inside of the meat, it slows the loss of moisture from the meat by
temporarily cooling somewhat the outside of the meat. The outside of the meat is always
hotter than the inside of the meat while the meat is in the cooker.
Occasionally, the chef person might choose to lower somewhat the temperature of the
outside of the meat. Conduction will continue from the outside of the meat to the inside
of the meat even as the mop is used and evaporation cools the outside of the meat. The
outside of the meat will still be hotter than the inside of the meat. The inside of the
meat will still continue to cook.
-------------------
[I read a series of posts by an engineer on the thermodynamics of barbecuing. Is
knowing any of this stuff useful in turning out a better product?]
Danny Gaulden--
I have been reading all the posts on "fluid effects on heat transfer", and
enjoyed it immensely. Also learned a thing or two on the "science" of heat
transfer--whether it be dry or wet heat--that's all nice, but will most likely not help
you much on making good barbecue. The design and function of your smoker, and how the heat
travels will have the greatest effect on how your product turns out, if you are cooking at
the correct temperatures, keeping the fire right, and know when to take the meat off.
I have been lucky enough in my life to have owned a great many different smokers. Redi
Smoke and Cook Shack electric, Weber, Sunbeam, Holland, and Char-Broil gas grills,
Char-Broil and Weber charcoal smokers, Brinkmann, Coleman, and Mr. Meat Smoker bullet
water smokers, Klose and Kingfisher big time home smokers, a couple of home made 55 gallon
oil drums, and my J& R Mfg. professional rig.
I have found this to be true--after you are the best you can be in knowing how to
barbecue, and really know the smoker you are cooking on, the smoker you are cooking on
WILL make a difference. Some pits do a better job than others, and this is simply a fact
of life. The least of your worries is about how much humidity is in the air, water pans in
the smoker, and if a water smoker will cook faster than a dry smoker. If you are cooking
on a first-class smoker, and have your act together, all this is irrelevant to the
finished product. I do think a little moisture induced into the smoker is good, but not
critical.
-------------------
[Does somebody have a scientific theory for why brining poultry makes the meat more
tender and moist? It can't be osmotic forces because the meat is dead.]
Bill Wight--
First of all, the membranes in dead meat cells can and do continue to conduct osmosis.
In fact, several entire industries are based on the osmotic properties of semipermeable
plastic membranes.
On the theory of brining, I wrote to an expert in the field, Professor Alan Sams, at
Texas A & M University and asked him what the mechanism was. He sent me two reprints
of scientific papers, one of his and one from Professor Jansky at the University of
Florida. The papers mainly dealt with various methods of chill-brining commercial poultry
but summarized the mechanism of how it works as follows: Brining makes the poultry more
tender and moist because the muscle tissues take up more water. The mechanism for this was
not stated in the articles. I would surmise it is a combination of simple diffusion and
osmotic pressures that ends up getting more water into the muscle cells and intracellular
fluids. The article stated that in the late 70's, several researchers, (Professors Hamm,
Arafa, and Jansky) determined that it was this added water within the muscle tissue that
made the meat more tender. And it's obvious that the added water makes the meat more moist
also.
On the added saltiness of the poultry after brining, Professor Jansky states, "The
average person might not increase his sodium intake substantially by consuming chicken
meat from brine chilled broilers; however, this product might not be suitable for persons
on sodium restricted diets." So if you are on a low sodium diet, don't brine your
birds with sodium chloride.
--------------------
[Can you tell me about what happens to meat while you slow cook it?]
Kit Anderson--
Meats are made of muscle, connective tissue, fat and bone. Muscle contains proteins and
glycogen. As the temperature of the meat increases, glycogen, a long chain sugar, is
reduced to simple sugars. This caramelizes and is responsible for one of the flavor
components.
Proteins (flavorless) are denatured to amino acids, which not only have flavors
themselves, but also undergo Maillard browning reactions, which adds another flavor
component.
While bone adds no flavor itself, the marrow is rich in methyglobulin and other
proteins. This reacts with smoke nitrites to give us the smoke ring. You may have heard
that "the sweetest meat is next to the bone". The proteins are reduced to amino
acids. Nutrasweet is an amino acid.
Fat is a very simple molecule that fills the fat cells in muscle tissue. Fat breaks
down to sugars, fatty acids, and triglycerides at low temperatures.
Collagen is proteins that have lots of side chain bonds. This makes them elastic. It
takes more energy to denature them than the simpler proteins of muscle tissue. Energy in
the form of heat will denature these proteins into the flavorful amino acids.
If the temperature is too high, the water in the muscle cells and the fat is rendered
out before the collagen melts. This results in dry, tough meat. Too low a temperature and
you risk bacterial activity.
Tough cuts of meat like brisket and pork butts benefit from low temperature cooking as
the collagen adds flavor to the meat. Less tough, more expensive cuts do not need this
phase and can be cooked at high temperatures for shorter periods. That is why ribs take
only a few hours and briskets take up to 20 hours.
-------------------
[I thought that the reason to raise the meat to room temperature for a wood burner was
to avoid condensation of undesirables in the smoke on the meat. For this reason, I bring
the meat to room temperature, put it into my electric bullet smoker, then wait a little
while before I add the wood chunks. Lately I've read that experienced List members put
cold meat into their smokers to get a better smoke ring and more smoke flavor. What's
going on?]
Danny Gaulden--
For 22 years I have taken the day's cooking straight from the walk in refrigerator in
my restaurant and into the cool smoker. The temperature in the pit will usually be around
125 to 140F. I have always felt if one wanted more smoke flavor and a deeper smoke ring,
this was the way to do it. My reasoning behind this is that I feel the meat is more
relaxed, and the pores are more open when the meat is cold. The smoke draws to it like a
magnet. Just like creosote does to a cold chimney until it gets heated up.
Now, here is where some of our novice smokers can get into trouble. If your fire isn't
established, and is in a high burn when you put on the meat, and you close the fire damper
down too much to try to keep the temperature down in your smoker for awhile, you will get
even more creosote on the cold meat than if you had let the meat reach room temperature
first. Not only will the 'good smoke' draw to the meat, the 'bad smoke' will also. That's
why I have stated in some of my earlier post to let the meat rest out of the refrigerator
for a bit before placing it in the heated smoker. It was less of a risk for a lot of you
and simply safer. However, it seems that some of the ones who have been smoking meat for a
few months are becoming good pitmasters, and we can discuss things at a more advanced
level. My problem with some of the things I do is that I don't know how to explain them, I
just know that they work. I guess that's why we have Kit around to help explain the
science behind what we're doing. From him, I have learned a lot about why what I do works
and can talk to people on a more intellectual level about it. It's always better to
understand why something works, not just that it works.
If you are using a water smoker, be it an electric, gas, or charcoal burner, this cold
meat technique shouldn't be much of a problem. Nor should it be with the Cookshack, etc.
However, doing this with a straight wood burners can be more challenging. You must know
how to start out with a low-heat fire, fairly smoky, and slowly bring the heat up without
causing a great commotion. It may be easier for you to go ahead and make a larger fire,
let it burn down to mostly coals, then throw in one piece of greener wood for smoke in the
early stages. That way, you can go ahead and close down your firebox damper a bit without
the problem of creosote, and maintain a lower heat in the cooking chamber for awhile.
Notice I said just for awhile. It's much easier to have a good bed of coals in the
firebox, and just add a log here and there to maintain and increase the heat, than to have
too few coals and have to chuck in a bunch of wood to bring the temperature up. I do not
maintain this low temperature cooking for a long time. I am continually slowly bringing up
the temperature until I reach about 240F in the cooking chamber. With the cold meat placed
in the cool smoker, and starting out with a cool, but clean-burning fire that I slowly
bring up, the meat turns out nice and smoky and with a great smoke ring every time.
==============
Kit Anderson--
I just got a copy of 'Professional Charcuterie' on Bill Ackerman's recommendation. It
is a great book on sausage making. One particular point of interest is the smoking
technique. Most of the recipes involving smoking call for putting the meat in at 135F for
a hour, going up to 155F, then higher until the internal temp reaches 160F.
This is not cold smoking, which is done at 80F. The purpose is to get the smoke ring
and its associated flavor to form at a maximum depth. The reaction stops when the meat
gets over 120F, or so. This makes a lot of sense when looking for 'bacon-on-a-stick' ribs.
I have advocated putting the cold ribs in a cold smoker and then starting the fire to
achieve this. It gives a smoke ring all the way through on baby backs but not all the way
through on spareribs.
This past weekend, I was visiting a friend that has a SnP Pro. He was cooking spares
and had lowered the grill in the cooking chamber to fit 6 full racks. He said he liked to
smoke at 200F but was having trouble with the ribs being tough. I saw that he was
monitoring temperatures on the lid which meant the temperature at grill level was probably
no higher than 135-150F. He is Polder challenged. The ribs had been on for 3 hours when I
got there.
So, I boosted the temperature up to 300F for two hours until dry bone started to show
on the ends. I could easily pull the ribs apart and found that the smoke ring went all the
way through. Bacon-on-a-stick spares, tender and moist. Try the initial low temperature
for a few hours next time you do ribs.
I did some research and found these Web sites on the smoking reactions in meat.
Click here to visit the first Web site.
Click here to visit the second Web site.
65C (149F) but most proteins start to denature at 120F. I think this is the temperature
when the enzymes are denatured and there is only heat affecting the myoglobin. Note
lines 4,5,6 in the table. They are the curing or smoke ring reactions. Reactions 7 and
above are the heat reactions because the myoglobin begins to denature.
What I learned and didn't know before was that bacteria are involved in changing sodium
nitrate to nitric oxide which bonds to the myoglobin at the site where oxygen would
normally occupy. Since these bacteria die at 140 and are very active at 120, that accounts
for smoke ring depth. Also, that there are three different smoke ring reactions giving
different colors based on the amount of oxidation the meat had before it started cooking.
There are three types of those reactions. That's why there are pink, red and purple smoke
rings.
-------------------
[Does the smoke ring have a taste?]
Kit Anderson--
Yes. The reaction of nitrates and nitrites in smoke, or chemical cures, with
methyglobin in meat results in the typical color we see in ham and other processed meats.
This also has a distinctive flavor. For instance, if you brine a brisket, it will taste
more like ham than beef. This is how turkey ham is made.
While the smoke ring does not show the total penetration of the smoke, its color and
size are an indication of the activity of the smoke when cooking.
So, you can produce thinner cuts of meat with a smoke ring all the way through and
things like baby back ribs will taste like 'bacon on a stick'. This reaction takes place
below 120F. So, in order to do this, you must put the ribs on when they are cold rather
than letting them come to room temperature. The smoker should not be too hot, 225F is
good. You should not use a ton of smoke. It will condense out causing the meat to be
bitter.
This is not the only way to barbecue ribs. It is only one way to get a very unique
flavor.
Editor--
I think in light of the many question asked (and some answered by Kit and Danny) about
the subject of barbecue smoke, smoke rings, smoke flavor and creosote, it might be helpful
if we take a look at this from a physical chemical point of view.
-------------------
[What is barbecue smoke?]
Bill Wight--
Barbecue smoke is a complex combination of particulates and gases that results from the
burning of wood. When wood burns, many different kinds of combustion by-products are
produced--this is a very complicated process and is affected by many variables, such as
temperature of the fire, the amount of oxygen available, the humidity, the type of wood,
the age of wood, etc.
Particulates--
What you see in smoke are actually the particulates, tiny bits of matter, from white
ash, to black carbon and many other materials. The sizes of these particles range from
about 10 microns down to less than 1 micron. A micron is one millionth of a
meter--bacteria are in this size range. In addition to the carbon and ash, there are also
some inorganic chemicals that are carried on the smoke particles, such as nitrates and
nitrites, usually as salts of sodium and calcium. The type of particulates that a
wood-burning fire produces is dependent on how clean, or complete, the combustion process
is, what kind of wood was burned, the age of the wood, etc. A clean-burning fire, one that
has all the oxygen it needs, will produce few particulates and a dirty fire, or one that
is starved for oxygen, will produce heavy particulates--including ash and soot. John
Willingham calls these smoke particulates 'dirt' and says that they are undesirable in the
smoking process. The particulate solids in the smoke cannot diffuse into the meat--they
are much too big to do that. The particulates stay on the surface of the meat. When we get
a dirty fire that generates lots of particulates, these materials do collect onto the
surface of the meat. This is why the meat turns black, from the soot that is generated by
a poorly-managed fire. The meat will also get black from the burning of sugars in the rubs
or sauces that are put on the meat, but that is another process.
An experienced wood-burning barbecuer will manage his fire in a way that very few
particulates are ever produced. His end product will come out of the cooking chamber a
beautiful deep, reddish-brown color. It will be free of any black sooty look. He has
managed during the entire course of the smoking process to keep his fire at the correct
level of fuel, air and heat, so that at no point during the smoking process did he let the
fire produce any soot or ash. The wood-burning beginner, however, will have periods during
the smoking process when the fire is well-managed and periods when the fire is
poorly-managed. During these poorly-managed periods, the fire will produce soot, ash and
creosote, all of which are detrimental to the finished barbecue product. At the end of the
smoking process, the meat may look black and sooty, and will probably have a bitter, or
'over-smoked' taste. As the beginner gains experience with fire management, the periods
when the fire is 'out of control' will occur less and less. After a year or so of smoking,
the beginner now finds that his meat is coming out of the smoker looking and tasting like
something that could win grand prize at the state barbecue championship.
Gases--
The gases in wood smoke are invisible, like air, and cannot be seen. These gases
contain carbon dioxide, carbon monoxide, water vapor, and many other chemicals. Wood is a
complex material, containing solids, liquids and gases. As the wood seasons, the gases
leave quickly and the liquids leave over a period of months and years. The complex organic
chemicals within wood are termed 'secondary metabolites'. These chemicals are produced by
the living cells of the tree and are important for the tree's growth, maintenance and
protection. These chemicals are classified by wood chemists into the following categories:
volatile oils, resins, fats and waxes, lignans, and simple and complex carbohydrates. A
typical tree may produce and store about a hundred of these organic chemicals within its
cells and bark. When these chemicals burn, by-product gases are given off in the smoke.
There is a big difference in the composition of the gases that come off a clean-burning
wood fire and those that come off a smoldering wood fire. One class of chemicals that
comes off a smoldering fire are called polycyclic aromatic hydrocarbons and contain some
really nasty stuff, some of them known to be carcinogenic.
It is beyond our interests to go any deeper into the chemistry of burning wood, but we
can simplify all this by saying that when barbecuers talk about 'good smoke' they are
really talking about not the particulates we can see, or the carbon dioxide or water vapor
gases, but a class of chemicals we will call 'smoke flavoring gases'. From my reading, I
do not believe that this class of chemicals is at all well understood.
Only the gases that result from the burning of the wood can get past the surface and
into the depths of the meat.
Creosote--
The term 'creosote' refers to a group of oily, bitter-tasting organic chemicals that
are produced during the fractional distillation of wood and coal. When creosote is
produced commercially, freshly cut wood is put into a distillation tower and heated with
very little oxygen present. The gases produced by this distillation process are condensed
on cooling coils in the top of the tower. In a smoker, we can get similar conditions--an
oxygen-starved fire, with the meat and the walls of the smoker becoming the condensation
surfaces. If your fire is well managed and you are using seasoned wood, you will not have
a problem with creosote forming and condensing on the meat. If your fire is starved for
oxygen and maybe some of your wood is a bit green, then it is very likely that creosote
will be produced and will find its way into your meat. Creosote in the smoke is a gas and
not a particulate. It condenses out of the gas as a sticky liquid. This creosote liquid
can get into the cells of the meat, so it is not just on the outside of the meat.
-------------------
[How does the smoke get into the meat?]
Bill Wight--
So now that we have a little more information on what smoke is, we can understand that
smoke absorption and adsorption by the meat is a complicated and highly variable process.
There are several physical processes that are taking place within your smoker.
Adsorption--
A process where the smoke particulates and gases are deposited onto the outside surface
of the meat.
Absorption--
A process where the smoke gases are transported into the cellular fluids within the
meat.
Diffusion--
The term diffusion in non-technical language refers to the process whereby liquids and
gases go from an area of higher concentration to an area of lower concentration. In
barbecue, the gases produced by the wood-burning fire are more concentrated in the smoke
surrounding the meat and less concentrated in the liquids of the cells within the meat. So
there is a 'driving force' that works to push the smoke gases into the meat.
Solution--
This is a term that refers to a liquid, a solid or a gas dissolving into another
liquid. When you make a brine, you put salt into water. The salt goes into solution in the
water. Gases also go into solution in liquids, as in carbonated sodas. Here, the gas
carbon dioxide goes into solution in the sugar-flavored water. Liquids can go into liquids
as when you add molasses to water.
Solution-Diffusion--
This is the process that describes how a liquid, a solid or gas goes into another
liquid and moves into and mixes throughout the liquid. In the example of carbonated soda,
the carbon dioxide gas is applied to the surface of the sugar water and the carbon dioxide
gas goes into all the liquid by the process of solution diffusion. It first goes into
solution at the surface and then diffuses throughout the liquid. If you place a spoonful
of salt in a glass of water and leave it undisturbed, in a few hours or days, the salt
will have gone into solution and the salt ions will have diffused throughout the liquid.
Saturation--
The term saturation means that a fluid cannot dissolve and hold any more solids or
gases, it has become saturated. In the soda example, only so much sugar can be added to
the water. When the water is saturated with sugar, no more sugar crystals will dissolve
into the liquid. When carbon dioxide gas is added to the soda, only so much will go into
solution. When the soda is saturated with carbon dioxide, then no more of that gas can be
dissolved in the sugar water. Temperature affects the saturation point. With warmer
liquids usually being able to hold more solids than cooler liquids (we warm a brine to
help the salt dissolve) and cooler liquids being able to hold more gases than warmer
liquids (when we warm a soda, the carbon dioxide gas comes off as bubbles). In barbecue,
there will come a point where the fluids within the muscle tissue will become saturated in
the smoke flavoring gases and liquids and no more gases and liquids can be added to the
cellular fluid. This may be one reason why putting cold meat into the smoker may increase
the smoky flavor, as the cold fluids in the muscle cells will take-up the smoke flavoring
gases and liquids faster than hot fluids.
-------------------
[What does this solution-diffusion process have to do with making good barbecue?]
Bill Wight--
Meat is really muscle tissue that basically consists of cell membranes, a combination
of many types of proteins and cellular fluids, containing water and dissolved solids (for
example salts and sugars) and gases and liquids (oxygen and carbon dioxide). When we smoke
a piece of meat, what is happening is that the smoke flavoring gases and liquids are
coming from the wood burning process into the cooking chamber and into contact with the
cell membranes of the outer muscle tissue. The smoke gases and liquids diffuse across the
muscle cell membranes and go into solution in the cellular fluids. The driving force here
is that the gases and liquids are soluble in the cellular fluids and are in a higher
concentration in the atmosphere of the cooking chamber than they are in the cellular
fluids. So the process of diffusion drives these gases and liquids into the cellular
fluids. Once across the cell membrane, the gases and liquids go into solution in the
cellular fluids and then diffuse throughout the cell. The gases and liquids then diffuse
out of the first cell and into the next cell in contact with the first and the process
starts again in that cell. This is how the smoke flavoring gases and liquids get deep
inside the meat, as much as a an inch in longer smoking sessions. Some of the smoke
flavoring gases condense out as liquids on the surface of the meat. These liquids then
begin to diffuse across the cell membrane into the cells and cellular liquids of the
muscle tissue. So we have some of the flavoring agents from the smoke diffusing into the
meat as gases and some diffusing into the meat as liquids.
-------------------
[Is this solution-diffusion a steady process?]
Bill Wight--
The cells within the meat accept these smoke flavoring gases and liquids more readily
when it is raw and cool and first put into the smoker and gradually accept less and less
of these smoke flavoring gases and liquids as the cooking process continues. There is
probably no absolute cutoff point, like after 2 hours, where the meat stops accepting
these smoke flavoring gases and liquids. As the smoking process continues several
conditions are changing. The meat is shrinking and it's surface and texture are becoming
less permeable as it cooks and browns (the bark is forming) and this makes it more
difficult for the smoke flavoring gases and liquids to diffuse into the meat.
Now we need to also know a little more about diffusion, the process that gets the smoke
flavoring gases and liquids into the meat. When we speak of diffusion, we are talking
about a process that wants to equalize itself, to attain a state of equilibrium. For
example, when someone is in a room and smoking a cigarette, the smoke and gases of the
combustion of the tobacco begin immediately to diffuse out into the air of the room. If
the person has only one cigarette and then stops smoking, the diffusion process continues
until every part of the room air has the same concentration of smoke, until the smoke in
the room has attained a 'state of equilibrium'. Now, if we were to start with a clean room
and erect a barrier across the middle of it that is made of paper, and this paper barrier
is taped to the walls and floor and ceiling so that the only way for the smoke to get into
the part of the room on the other side of the barrier is to go through the pores of the
paper. Now when the person smokes one cigarette the smoke will diffuse throughout their
side of the room but the smoke but will have trouble, or be impeded from diffusing, into
the other side of the room because of the paper barrier. Eventually, the smoke will
diffuse through the paper barrier until the smoke concentration is the same on both sides
of the paper barrier. The process of diffusion is driven by an unequal amount of smoke on
each side of the paper barrier. When we start out, the smoke is more concentrated on one
side of the paper barrier and less concentrated on the other side of the barrier. As time
goes on, the smoke gradually becomes equal on both sides. The smoke will never be in a
higher concentration on the other side of the barrier, as there is no force that will make
smoke concentrate on the far side of the paper barrier. The smoke must eventually come to
a state of equilibrium in both parts of the room.
Now let's imagine that the paper barrier across the room represents the surface of the
meat and the cell membranes of the muscle tissues within the meat. Let's make this example
more like smoking meat and say that when the smoking process first starts, the pores in
the paper barrier are large, and smoke will diffuse through the paper at a fast rate and
as the smoking process continues the pores in the paper 'clog up' and get smaller and the
smoke diffuses through the pores at a slower rate. As we smoke a piece of meat, several
things are happening. First the 'pores' of the meat are more open and the smoke flavoring
gases and liquids can go through these bigger holes at a faster rate. Also, when we start
the smoking process, the meat has no smoke flavoring gases and liquids dissolved in the
fluids of the muscle cells of the meat and therefore there is a higher driving force
available to drive the flavoring gases and liquids into the fluids within the cells. As
the smoking process continues, the pores of the meat get smaller and the 'skin' on outside
of the meat gets thicker. So the overall effect is that the smoke flavoring gases and
liquids cannot go into the meat as fast as they did at the start. As the smoking process
goes on, less and less of these gases and liquids can get into the meat. Also, as the
smoking process continues, the fluids with the cells get closer to the point of saturation
of the smoke flavoring gases and liquids. At some point in the smoking process, no
additional smoke flavoring gases and liquids can be absorbed or taken into the fluids of
the cells.
-------------------
[OK, I understand that it is getting harder for the gases and liquids to get inside the
meat as the smoking process continues, but is there a point where no more smoke flavor is
imparted to the meat?]
Danny Gaulden--
Even though the smoke flavoring gases and liquids may not penetrate the meat nearly as
deep after a few hours of smoking, I feel they still continue to be adsorbed on the outer
surface of the meat. The smoke flavor can become quite strong and bitter if the fire is
not managed correctly, or it can be a positive addition to the flavor if the fire is
well-managed. Smoking beyond the 2-6 hour period definitely adds more 'smoke flavor' to
the meat, and there is a great distinction in flavor between 'smoked until done' meats,
and meats that were smoked for a few hours, then finished off with just heat, by being
wrapped in foil and left in the smoker or put into an oven.
When one takes a bite and starts to chew, the eater doesn't know if the smoke flavor is
coming from the center of the meat, the outer third, or the outside surface. He just knows
it tastes smoky. So, I feel that the 'continue smoking until done' process does add flavor
all the way through the cooking process. To what degree this is attained depends on how
smoky one wants their meat to be, and how well they manage their fire.
-------------------
[Why can't we wash off the creosote taste once it gets on the meat?]
Bill Wight--
The creosotes that form from a poorly-managed fire are gases and these gases condense
on the surface of the meat. Once on the surface, they diffuse into the interior of the
meat. So a piece of meat that has been subjected to creosote conditions for a long period
of time cannot be rescued by washing it off, as the bitter-tasting chemicals have
penetrated into the meat. If the creosote condition lasts only a few minutes, then it may
be possible to wash off the meat, or cut off the bark, and remove the bitter tasting layer
and save the meat. But if the creosote conditions remain in the smoker for a longer time,
then you have almost surly ruined the meat as the bitter taste will have gone too deeply
into the meat to be removed. Danny Gaulden has testified to this in his early days of
smoking. He's had a few pieces of meat that were totally ruined because his fire got out
of control and produced some nasty creosote that went so deeply into the meat that the
bitter parts could not be trimmed off.
-------------------
[Does the smoke ring continue to grow as long as the meat is in the smoker and there is
smoke?]
Kit Anderson--
The smoke ring reaction stops when the meat gets to about 120F. The smoke ring is only
one of the reactions taking place in the meat and has its own associated flavor but smoke
penetration is temperature dependent.
-------------------
[How do you suppose that the nitrate and nitrite salts get onto the meat from the fire?
Are they carried aloft as salts attached to the particulates in the smoke?]
Kit--
The ash is loaded with potassium and sodium nitrates. That's why you need wood smoke to
get a smoke ring.
-------------------
[So you need some particulates in your smoke too, not just the gases?]
Kit--
Right. With charcoal, you get no smoke. With lump, you get a little. With lump and wood
you get more, with just wood you get the most. With each, an increase in smoke ring depth.
Nitrates are organic salts and cannot by themselves be gases.
