30-40 degree temp difference????

Started by NYFrank, July 20, 2013, 08:33:25 AM

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NYFrank

Hi all. I recently started smoking so I'm not sure if this is the issue or not as far as temp swings go. When I set the oven temp to 160 it will climb up to 170-180 even with the damper half open. I also put a 2nd temp probe in the oven and that one reads about 15 degrees lower then the one built into the unit. I did set the 2nd prob mid way in the unit. The 2nd part of that question is I just did a batch of sausage (about 5 lbs) in 3" casing. I dried it at 130? At least that what the Bradley unit said. Now I think it was much hotter then that. Raised the temp to 140 and then to 160. The meat in the end had good flavor but was kinda mealy (cracked in half) I used 3lbs of eye round, 1lb pork butt with fat, and 1.25 lbs of pork fat.

I read up on a PID controller, I just would hate to spend another $170 when I expected this one to work correctly. I would have bought a non- digital unit. Does anyone know any reason the Bradley unit is so off as far as the temps go.

Any feed back would be great.

Thanks Frank

TedEbear

The Bradley temp control has a wide temp swing.  For smoking most things it doesn't matter.  In my case, even though it doesn't matter, I like precision.  Thus, I purchased an Auber PID controller and now the temp stays within 1-2 degrees of what I have it set at.

You don't have to spend $170 for a PID controller.  A basic single probe unit that you install in either the SG or a project box costs around $45.  The total cost would be around $70-$80, depending on how many things you can scrounge up for free (you can get a heat sink out of an old computer) and how many you have to purchase.  There's the K-type thermocouple, 25A solid state relay, a project box (if you're not installing it in the SG), some wire, a heat sink, off/on switch, terminal strip and maybe a few miscellaneous parts.

Most people just purchase one of the plug and play versions, although I like to tinker plus save a few dollars along the way.  Here's my setup:





NYFrank

Looks very nice and rather easy to build. Something I will look into, thanks. Its just too bad the built in one isnt designed to be accurate. I wounder if you can modify where the temp sensor is and just add a temp probe to it so that is is more centered in the unit.

NYFrank

So I bent up the back drip tray vents and filled the space between the drip tray and the back wall with foil. I also closed the top vent to that it is only open 1/8 of the way. This seems to help with the big temp difference so not its down to less then 10 degrees and at times the two probes were only 6 degrees off. I only was able to leave it like this for less then an hour cause I had to got to work. If anyone tries this please post your results

frank

KyNola

Frank, trust me on this.  Open your vent.  How much space do you have between the drip tray and back wall?  Mine is pretty much flush with the back wall and can't imagine having enough room to fill the space with foil.

Do yourself a favor.  Get used to how your Bradley cooks before you start stressing over temp swings.  If you're smoking/cooking ribs, brisket, butts and many other cuts of meats the temp swings aren't critical.  As the meat comes up to temp you will see the swings lessen and lessen.  If you're smoking sausages that you stuffed or certain recipes for fish the temp swings are a bit more of an issue.

Check your house oven.  You'll find temp swings there too.

tskeeter

Frank, some observations about temperature control in a Bradley.  First, fairly wide temperature swings are normal.  In the range of set point +/- 15 - 20 degrees.  As others have said, these swings aren't a problem when smoking many products.  And similar temperature swings are common to household ovens.  Some of the more temperature sensitive products are sausage and fish.  Second, the Bradley temp sensor is mounted directly above the heating element.  Because of the location, it tends to read a temp that is higher than the area of the smoker where the product you are smoking is located.  Third, the temperature distribution in a Bradley tends to be hottest in the back at the bottom, above the heater element, and coolest at the top close to the door.  About a year ago a forum member did a temperature distribution analysis that you might find helpful.  Many another member remembers this thread and can provide a link?  Many forum member use this heat distribution pattern to their advantage.  Putting smaller cuts of meat on the upper racks and larger cuts on the lower racks.  Or using the upper racks to smoke items where you want to keep the temperature down, such as cheese.

If you are going to be doing a lot of sausage, a PID might be a worthwhile investment.  Another alternative would be to do more of a cold smoke.  And then bring your sausage to their finished IT using a hot water bath.  Many threads on the sausage forum discuss using this technique.

By the way, I, too, crimped the vents on the back half of my v-tray to even out the front to back heat distribution in my 6 rack.  Don't know if it makes much difference, but it was so easy to do and a no cost modification, so why not? 

TedEbear

Quote from: tskeeter on July 20, 2013, 08:15:17 PMAbout a year ago a forum member did a temperature distribution analysis that you might find helpful.  Many another member remembers this thread and can provide a link?

I think this is it:  Couple of Dual Element Questions

Being of a curious bent I have started some testing of the 6-rack temperature distribution.

I set the PID to 150 F for all of the tests.  I am only part way through but what I have found so dar has surmised me.

I had assumed that having the PID probe at the center of the cabinet would give the most even results so that is where I placed if for the first set of tests.  I use an Iregon Scientific wireless thermometer for checking the temps.

With the OS probe next to the PID probe there was no difference in temps.
The right front st the same level read 13 degrees higher.
The left front read the same as the PID.
The left and right rear read 8 degrees higher.
Moving the OS probe to the top rack center I got a +2 degree reading.

Now for what I suspected:
Moving the OS probe to the center of the bottom rack read 192 degrees when element was on.  It only dropped a couple of degrees when the element was off.

At this point I was curious as to how the PID would react to the element heat when coming up to temp.  This is where I was surprised.  I moved both probes to the bottom rack center.  I ran auto-tune on the PID because I was getting 8 - 10 degree swings on the PID.

After auto tuning the PID it would go to 150 and sometimes 151 degrees. The OS read 151 all the time.

Heating to et point was a little slower but it was smoother.  Took me a while of thinking but I think I know why it worked this way.

As soon as the temp would hit 150 degrees from the element the PID would turn it off.  When it would drop below 150 it would come back on.  The temp at the bottom would be kept at 150 - without the higher temps seen when the probe was higher in the cabinet.  I got a reading of 168 at the top of the cabinet.

I have a bunch more testing to do - ran out of daylight.


NYFrank

Thanks for all the great feedback. I will look more into what some have suggested. Yes I do mainly sausage so this is why I am concerned about the temp getting to high. We live in the North Country of NY so in winter it gets too cold to run the smoker, at least I couldnt do it with the wood/dome one I had. I would like to try and get a bunch done before its gets cold. Which up here is only 5 weeks away  :(  The ribs and chicken we made came out just fine. The sausage I did I feel have too much fat melt and this is what is causing the cracking when I slice them.

KyNola-- I have enough space on the back wall to be able to fold a piece of foil several times and fit it between the wall and tray. I would say maybe the space equal to a nickle.

TedEbear

Quote from: NYFrank on July 21, 2013, 05:56:38 AMWe live in the North Country of NY so in winter it gets too cold to run the smoker, at least I couldnt do it with the wood/dome one I had.

Some of the year-round smoker diehards put some type of insulation on the outside walls of their Bradley, which they say greatly helps in cold weather.  Others have built or purchased small shelters to shield their Bradley from the elements, whether it is rain or cold.

Underwear for My Smoker


GusRobin

Quote from: TedEbear on July 21, 2013, 08:02:51 AM
Quote from: NYFrank on July 21, 2013, 05:56:38 AMWe live in the North Country of NY so in winter it gets too cold to run the smoker, at least I couldnt do it with the wood/dome one I had.

Some of the year-round smoker diehards put some type of insulation on the outside walls of their Bradley, which they say greatly helps in cold weather.  Others have built or purchased small shelters to shield their Bradley from the elements, whether it is rain or cold.

What he said -- also there are folks on here that live in Canada and Alaska that smoke in the middle of winter so you should be okay in NY if you use something to shield it.
"It ain't worth missing someone from your past- there is a reason they didn't make it to your future."

"Life is tough, it is even tougher when you are stupid"

Don't curse the storm, learn to dance in the rain.

tskeeter

 We live in the North Country of NY so in winter it gets too cold to run the smoker

In my area in the winter time, it's not the smoking that becomes a challenge.  I can always smoke.  It's the cooking part of the process that can become difficult because of the temperatures required.  My alternative --  smoke in the Bradley.  When the smoking is complete, move everything to the house oven for the cooking.  A minor inconvenience, but keeps me going year round.

RAF128

I smoke year around but my smoker is set up in my heated garage and vented to the outside.

Habanero Smoker

NYFrank;

I know what you mean about the cold. I use to know a friend who lived in the Adirondack area, and he would say; "There are only three seasons. July, August and winter". :)

Some of the areas in the Adirondacks, such as Old Forge and other areas are particularly cold, and you may as well as live in Alaska. I don't live that far north, and the winters in my area have been getting milder each year, for some time. So I don't face the same issues you have. Though if you follow TedEBear's suggestion and link, keep the smoker out of the wind, you may be able to get your smoker up to a set temperature, and sustain that temperature with a small load during the winter.

But I would do a test run this winter before actually attempting to cook something in the winter. This winter fill a disposable foil pan with about 4 pounds of sand, and mix in 1 pound of water (2 cups). This sand/water mixture is to simulate 5 pounds of meat. Leave the pan uncovered, and place it in the Bradley and record how it performs. I would record hourly, and use Bradley Smoker Log as a guideline.



     I
         don't
                   inhale.
  ::)

rveal23

I'm lucky, I live in Warm Weather LA. I don't know what I would do if I would live in cold temp. Everyone here is in heavy coats and beanies when the temp reaches 65.. AngeleƱos are weirdos.
* DBS w/ 900watt Mod
* Webber Kettle Grill
* Hybrid Grill

Saber 4

I have more issues with heat here in Texas, I want to do some cold smoking but I'm figuring I'll have to wait for winter when we get back down under 80.