High altitude corrections?

travelerjjm · May 27, 2005, 04:29:30 PM

I've seen a few of Andy's comments on high altitude smoking, but I have some questions:

- How do I correct time and temperature for altitude? Jerky seems to go very fast, unless I slice it much thicker than recipes recommend. Pork butts seem to be firm as Andy pointed out.

- Do I need to change rubs or brines for altitude? I haven't but maybe I should.

- Should I adjust the smoke/no-smoke time ratio?

Thanks,
john
["long time reader; first time poster" [:)]]

manxman · May 27, 2005, 05:10:16 PM

Hi travelerjjm:

<blockquote id="quote">quote:<hr height="1" noshade id="quote">How do I correct time and temperature for altitude? <hr height="1" noshade id="quote"></blockquote id="quote">

The link below provides information on temperature variation with altitude and should make it possible to work out if any change is required for your local situation.

I would imagine you would have to be at quite an altitude for it to make a significant difference.

To me if you do have to adjust the temperature from what is quoted in a cook book or forum because of altitude you would not have to adjust the times as well,the other variables should broadly be the same if you have aligned temperature.

Conversely, if you don't adjust the temperature then the cooking times may need altering, although the temps. must still meet minimum food safety levels.

http://www.bradleysmoker.com/forum/topic.asp?TOPIC_ID=1399&SearchTerms=thermometer,checking

Not sure about the other bits you questioned? Sure there is someone with first hand knowledge who can help.

Manxman.

travelerjjm · May 27, 2005, 05:29:08 PM

Thanks, Manxman. I'm at 8500ft. Water does boil at a lower temp here and I have calibrated my thermometers for it. One factor might be that as air insulates, less air (due to altitude) might mean less insulation. Dunno.

JJC · May 30, 2005, 06:35:59 AM

Hi John,

Welcome to the Forum! I'm sure there are cookbooks that deal with cooking at altitude, and Manxman's advice is generally applicable. At 8500ft, water is boiling at around 196F, rather 212F like here in Boston or on the Isle of Man. Without getting into the technical detalis, the problems of water boining at such a low temp means you are also losing moisure from your meat that much more quickly, so you need to compensate for that is some way. You might want to consider changing brine/rub recipes, even though theoretical considerations might suggest a reduction in salt or sugar content in the brine might be helpful, but that's the last think I wold do if you are using the brine as a way of curing the meat. Injecting meat may be a good way to get more moisture in before starting the cooking process. The final consideration would be to increase the cooking/smoking temp, which might seem counter-intuitive but should result in faster coagulation of proteins (cooking) and rendering of the fat and conversion of collagen into gelatin.

However, please keep in mind this is based on my theoretical knowledge, and I'm sure thee are specific cookbooks available on cooking/grilling/smoking at high altitudes. Let us know what you find out!

John
Newton MA

Habanero Smoker · May 30, 2005, 08:12:58 AM

The boiling point of water is related to the barometric pressure. At higher altitudes the barometric pressure drops, as the barometric pressure drops, so does the boiling point of water. This site has one of the best charts I have ever come across http://www.biggreenegg.com/boilingPoint.htm .

I have read references that some like to bring their brisket up to 200 degrees. One thing you need to consider - never bring your internal meat temperatures at or above the boiling point of your area, this will dry you meat out completely.

JJC · May 31, 2005, 04:36:35 AM

Hi Hab,

Your point about never bringing the cooking temp above the water boiling temp makes a lot of sense if there is no added moisture (either by injection of the meat or by placing water in the water bowl). On the other hand, water will evaporate at any temperature, it just happens faster as the temperature rises (or the atmospheric pressure decreases). Meanwhile, the denaturing/coagulation of proteins is required for meat to be properly cooked, and the higher the temp the faster the proteins denature. So my question is: Are you better off increasing the available moisture and cooking the proteins a bit faster (ie, higher temp, shorter time), or is is still low and slow even at the high altitudes (with at least some added moisture, of course)?

John
Newton MA

Habanero Smoker · May 31, 2005, 06:08:50 AM

My response was to travelerjjm statement on what causes the lowering of the boiling point. So I didn't have much time to give thought to your theory, at the time.

I Googled "high altitude cooking". Most sources that mentioned cooking meat stated that the only consideration to take into account is when you are deep frying (lower the oil temperature), pressure cooking (increase pressure and time) or when braising or stewing meats (increase water amounts and cooking time). Any reference to roasting stated that there should be no adjustment made.

Harold McGee states that at high altitudes, such as in Denver the meat cooking process will be gentler (due to the lower boiling point), but more time consuming.

My take on this is either smoke low and slow, knowing that it will take longer to cook. Or increase you temperature to the high end of "hot smoking" temperatures, to keep your cooking times more reasonable. My guess would be brining and/or adding more moisture will have little effect when cooking with hot air at higher altitudes.

JJC · May 31, 2005, 06:23:09 AM

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Habanero Smoker
 My response was to travelerjjm statement on what causes the lowering of the boiling point. So I didn't have much time to give thought to your theory, at the time.

I Googled "high altitude cooking". Most sources that mentioned cooking meat stated that the only consideration to take into account is when you are deep frying (lower the oil temperature), pressure cooking (increase pressure and time) or when braising or stewing meats (increase water amounts and cooking time). Any reference to roasting stated that there should be no adjustment made.

Harold McGee states that at high altitudes, such as in Denver the meat cooking process will be gentler (due to the lower boiling point), but more time consuming.

My take on this is either smoke low and slow, knowing that it will take longer to cook. Or increase you temperature to the high end of "hot smoking" temperatures, to keep your cooking times more reasonable. My guess would be brining and/or adding more moisture will have little effect when cooking with hot air at higher altitudes.

<hr height="1" noshade id="quote"></blockquote id="quote">
Thanks for the info, Hab. Does the brining comment apply to injection brining as well? I would thnk that it might provide a reservoir of extra internal moisture that might help counteract the faster evaporation rate . . . [?]

John
Newton MA

Habanero Smoker · May 31, 2005, 07:06:36 AM

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JJC
Thanks for the info, Hab. Does the brining comment apply to injection brining as well? I would thnk that it might provide a reservoir of extra internal moisture that might help counteract the faster evaporation rate . . . [?]

John
Newton MA
<hr height="1" noshade id="quote"></blockquote id="quote">
This is only a guess, because I could not find any definite information about roasting meats at high altitudes. From what I was able to find; my take would be if you are cooking with hot air brining or injecting brines would have the same effect in Boston as it does in Denver. It appears that the problems of cooking meat at higher altitudes only occurs when you reach the boiling point, such as braising or stewing. If you cook meat to internal temperatures under 185 degree F, there should not be any significant difference of loss of moisture at higher temperatures; just longer cooking times.

travelerjjm;
I also seen many references that one should contact their local county cooperative extension office for more information about high altitude cooking. If you obtain any information, can you please share with the group.

travelerjjm · May 31, 2005, 02:42:42 PM

Thanks everyone, especially Habanero.

I understand the lower boiling temperatures well and have lots of experience with high altitude cooking. It never occurred to me, though, that the boiling point would impact smoking. I did some beef jerky and checked it at what would have been half way through the recipe and discovered that it was very dry. Likewise a pork butt I did (with a dry rub plus mustard) tasted great, but was dry and not even moist enough to pull apart.

I will try adding moisture and some temperature experiments and report back.

Andy · May 31, 2005, 05:19:39 PM

My experience so far...about 20 to 25 smokes...is that my butts are never dry and my chicken q's is never dry...but neither is going to go much above 180 internal.

Plus, it takes a significant longer time to get the temp up to 200 when the bradley is full.

I also find that when I do ribs...they are done in about 4 hours.

So I think stuff cooks quicker..but you will never see the high temps that you would at lower altitudes.

As far as high altitude cook books....forget about them....they are all calibrated for 5k...and at 8500 ft...that is a significant difference to 5k. Figure 14k is considered the death zone...that means you are less then 1/2 the normal oxigen in the air as at sea level. The average person breaths in 21% oxygen..at 5k you breath in 14%...at 14K you breath in about 5%...the amount you need to live...that is why it is called the death zone for climbers. My guess is at 8500 you are at about 11 or 10%. The the air pressure and boiling point of stuff is much different them the 5k the cook books say is high altitude.

So you got to play it by ear and experiment. I screwed up a few things....but have found that most meat after being cooked can be chopped up finely for nachos...bbq nachos are awesome and no one can tell the difference.

bsolomon · June 03, 2005, 08:14:47 PM

My smoker's at 8000 ft and I haven't noticed any distinct difference in time resulting from the use of the recommended heating temperatures. Of course, I always base by timing on the internal temperature of the meat, but the rough rules of thumb seem to apply (i.e., 1 1-1/2 hrs/lb for brisket, etc...)