Dedicated refridgerator for dry aging Beef.. That's my project this weekend!

[slief]

There doesn't seem to be a good place here to start this thread so I figured this would be the best place to put this topic. Especially since this endeavor is primarily for the beef. I looked at the drying section and it seemed to be more about drying foods as opposed to dry aging. Mod's, if this doesn't belong here, sorry and please feel free to move it accordingly.

I have been reading and salivating over all the "Dry Aged" success stories here and love dry aged steak. I have done a ton of reading here as well as elsewhere on-line and decided to make a dedicated compact fridge for dry aging. This is design is based on information I have found on-line with a bit of my own variations.  

The idea is that the fridge will be set to maintain a 35*-37* temp while the humidity controller/humidifier will maintain a constant a humidity of between 75% and 80% humidity. I should have this completed by end of this weekend if not tomorrow. The intent will be to test it out beginning next week with a 16-21 day aged prime rib. I plan on doing dry run tests over the coming days. Any feedback is welcomed.  

I plan on documenting this in enough detail so that any of you can replicate this with ease. This of course assuming that it works as I expect it should. Bare with me over the next couple days as I put all the details together. I will edit the list below with links to the parts I used for this build. This will also serve as a how to for those interested.

The list of parts includes:

4.4 Cubic Ft Danby Fridge without icebox

Humidifier

Humidity controller

Wireless humidity temp/monitor

GFCI power outlet

Exterior rated 110V receptacle

12V blower fan

12V AC Adapter (for fan)

*Misc. Parts.

Here is the pile of parts.

First thing was to drill a hole in the fridge to accommodate the power for the outlet that will be permanently mounted in the fridge. Stay tuned. More on that tomorrow..I opted to run the wire for the power outlet though the bottom of the fridge as it was the most convenient.

 

[sausageboy]

I use a small fridge.

No fans, controllers or humidifiers.

Beef is wrapped in several layers of cheesecloth that's been treated with boiling water and then dried.

If humidity needs adjusting I place a damp kitchen towel in the fridge, but there's rarely a need.

The most important thing is to keep the fridge immaculately clean and sanitized.

 

[SmokinAl]

Looking forward to seeing the progress on your project. I've been wanting to build a similar setup for some time.

 

[slief]

Its done! I need to let it sit for the day as I laid the fridge down to get the bottom and the coolant will need time to settle back down. More pics to come tomorrow when I do a test run.

First I added a small power plug on the side of the power outlet box so that the AC adapter for the fan can be kept outside the fridge. I also added a small plug to the exterior so that the AC adapter isn't hard wired to the fridge. Instead, it plugs into a plug on the outside which in turn powers the plug for the fan. 

I then sealed up the hole that the wires run through with some silicone.

The power box  was then mounted and a good bead of silicone was run around it to insure that moisture doesn't get caught behind or below the outlet.

Next the power outlet was installed inside the box. This outlet is an exterior water resistant outlet so it should handle the humidity.

Last was sealing the hole in the bottom of the fridge and soldering on the external power connection for the fans AC Adapter.

Here you can see the AC adapter plugged in to the exterior fan plug.

Fan and Humidity controller plugged in.  

 A shot of the humidifier with the power contraption.. I forgot to plug the fan in for this shot.

 

[slief]

Here is a shot with everything in the fridge. I also plan on making a sausage hanging rack which will be very simple.

 

[chef jimmyj]

Looks Really Good!...Like SausageBoy said keeping it Clean can't be over stated and Staying out of it, is one of the best ways to keep bacteria and mold at bay. Every time you open the door you suck a whole bunch of Bacteria and Mold Spores in with the air...Have fun, I got my eye on this because after my Cheffie Daughter graduates from the CIA , I get her Dorm Refrigerator...JJ

 

[woundedyak]

Nice work! I really dig it! I'm a Danby dealer and in my experience, The Danby has a really hard time maintaining anything under 40 degrees. If you give it plenty of breathing room (1-2 feet off the wall) it will have a better chance of making it under 40. Keep the updates rolling

 

[slief]

Nice work! I really dig it! I'm a Danby dealer and in my experience, The Danby has a really hard time maintaining anything under 40 degrees. If you give it plenty of breathing room (1-2 feet off the wall) it will have a better chance of making it under 40. Keep the updates rolling

That's great to know! Hopefully that won't be an issue as I drilled my warranty away! I will probably put it in the garage where it's a bit cooler.

I decided to fire it all up so it will certainly be interesting to see if it can hold 35*.. I have to admit that I am a bit concerned after you mentioning that.

I will continue to update this thread while I test as well as when I try my hand at aging meat. That should commence Monday if all goes well with my testing.

 

[rbranstner]

Wow. All of that is WAY over my head.

 

[slief]

So far so good!

 

[slief]

It seems as though I have encountered a minor issue. This refrigerator is an auto defrost model. The temp swings on this refrigerator are upwards of 6* or more depending on the ambient temperature outside of the fridge. . Once the compressor turns off, the compressor stays off for a certain amount of time until the cooling plate inside the refrigerator has thawed and is ice free. During that period the temp will rise several degrees until the compressor turns back on.. The thawing process creates another issue. The humidity skyrockets. Note to self: Find a fridge that is not auto defrost. There is a good solution though.

I am very big into salt water aquariums. It's been a passion of mine for more than 20 years. I use a chiller on my tank and the chillers controller (Ranco ETC-111000) is an external digital thermostat that the compressor plugs into. The controller can maintain preset temp within 1 degree. You can actually program what temp the compressor turns on and what temp it turns off. Tomorrow my plan is to re-wire the refrigerators compressor so its controlled by one of the Ranco units. I happen to have a spare. It should be simple and hopefully it will solve that problem and also give me a level of temperature control that would be impossible with a typical refrigerator thermostat. I also think I will end up adding some bottles full of water to the door shelf's to give me a little more cooling surface inside the fridge which should reduce the compressors run intervals.

Here is a picture of what the proposed thermostat looks like... This controller will plug into the wall outlet. The compressor which is also 110V will plug directly into this device. I will need to rig a plug connection to the compressor but that is simple.  The controller has its own temp probe which I will route into the fridge through the drain hole below the cooling plate. This drain hole is where the melted ice drains through during the auto defrost cycle. I will be able to position the temp probe where ever I want which will help me get more accurate temps where ever the meat is positioned on the fridge. More to come tomorrow when I rig this thing up and test it.

 

[chef jimmyj]

It will be some more work and cutting but if you add an Exhaust fan to suck out the humidity controlled by the humidity upper set point, you will need a small Fresh air intake hole also opposite corner, then you have more options...This can be used as a Dry Aging Refer in cool months when it can do 38*F and a Dry Curing Cabinet in warm months when you can run it at 55*F with ease...JJ

 

[sausageboy]

! think that you're over-thinking this.

As long as the average temp is good, some fluctuation is not a big deal.

I would take (and I do) a calibrated instant read pocket thermometer and place it in a cup of water...a travel mug works good...that'll give you an average running temperature.

I also use a hydrometer (cigar humidor type) that can be calibrated.

I've been doing it this way for over 20 years without serious problems.

The extra bottles of water for a bank are probably a good idea.

 

[slief]

! think that you're over-thinking this.

As long as the average temp is good, some fluctuation is not a big deal.

I would take (and I do) a calibrated instant read pocket thermometer and place it in a cup of water...a travel mug works good...that'll give you an average running temperature.

I also use a hydrometer (cigar humidor type) that can be calibrated.

I've been doing it this way for over 20 years without serious problems.

The extra bottles of water for a bank are probably a good idea.

Perhaps you are right. My concern is that if I want to keep the cooler set to 35* and it jumps to 41-42* during the defrost cycle, that 42* will have an affect on the aging process and cause the aging to accelerate or worse induce premature spoilage. On a warmer day, the temp may rise beyond what I have seen which has be even more concerned.

Also, I was seeing 90%+ humidity during the defrost cycle which also isn't ideal. The controller I was going to switch to will allow my greater temp control while eliminating the additional humidity from the defrost cycle. 

Is your fridge an auto defrost model??

On the subject of humidors, what model are you using for your humidity? After reading your post I looked up some cigar humidor humidifiers and they look much more practical and efficient than the humidifier/controller combo that I am currently using and price wise, they are not out of line with my current combo.  

 

[sausageboy]

The fridge that I have is a GE, no auto-defrost.

Just to clarify, I use a cigar humidor hygrometer that can be calibrated.and not a humidifier.

HygroSet II Hygrometer..... 
http://tinyurl.com/6o4ffs8  

You can calibrate it with some salt saturated water inside a small container. 

Calibrating a hygrometer..... 
 

 

[slief]

The fridge that I have is a GE, no auto-defrost.

Just to clarify, I use a cigar humidor hygrometer that can be calibrated.and not a humidifier.

HygroSet II Hygrometer..... 
http://tinyurl.com/6o4ffs8  

You can calibrate it with some salt saturated water inside a small container. 

Calibrating a hygrometer..... 
 

Thanks for the clarification. I have rewired the refridgerator and bypassed the thermostat. I still have power to the fridge light but the compressor can now be controlled through an external thermostat like the one I mentioned above. I have the fridge in a cooling cycle right now. Once it hits 35*, I will shut the power off and let it sit until the temp hits 37* at which point I will apply power again and see how long it takes for the compressor to kick back on. If it turns back on within a a few minutes, I will hook up the new thermostat and route the new temp probe and give it a whirl. I will update this thread in a couple hours with the results. Hopefully the thermal overload switch on the compressor isn't the control point for the auto defrost. If it is, this might just be an effort in futility. Either way, this is pretty simple and would only take a couple minutes to return the refridgerator back to normal operations.

 

[slief]

The new thermostat is connected & the fridge is cooling. I have it programmed to chill to 34* with a 2* differential. If all goes as planned, it will cool until 34 then turn off and back on when them temp hits 36* & cool back down to 34*. My fingers are crossed!

 

[slief]

It looks like it's going to work. The fridge shut off at the preset temp. Once the temp rose a couple degrees, the compressor turned back on. I just fired the humidifier up and the fan and will let it cycle for a hile and see what happens. Hopefully the temps will remain stable to a degree or 2 and the humidity will be consistant. Update to follow shortly.

 

[slief]

It seems to be working great. Its been running for a couple hours now. Temps are stable with only 2* of swing between compressor runs and humidity is holding steady at a preset of 73%. Gone are the several degree temp swings and elevated humidity from the auto defrost cycles. I will continue to run it today and into tomorrow noting temp and humidity changes after which point I will make a Costco run to grab a prime rib. This got a little more complicated than I had expected however its great to be able to set a fridge temp with the push of a button and know that it is spot on as opposed to turning a knob that doesn't decipher the preset temp.   

It will be some more work and cutting but if you add an Exhaust fan to suck out the humidity controlled by the humidity upper set point, you will need a small Fresh air intake hole also opposite corner, then you have more options...This can be used as a Dry Aging Refer in cool months when it can do 38*F and a Dry Curing Cabinet in warm months when you can run it at 55*F with ease...JJ

Chef Jimmy,

Interesting idea! I am not sure I am ready to start cutting holes in this thing yet.It would however be kind of cool to have electric controlled dampers on the intake and exhaust that would open and close via a humidity controller so that cooling isn't as impacted as much from the vents. Being that this is a smaller refrigerator, I would imaging it will be much more sensitive to that kind of ventilation than would a large refrigerator. Then there would also be the concern of contamination entering from the vents as it would no longer be a sealed environment.  

Here is a shot of my 'Franken Fridge' with its new controller mounted.

Here is a shot of the inside with the new temp probe run into the fridge through the drain hole. I mounted it using an extra Maverick grill probe holder that I had. I can move the probe around as needed as there is plenty of slack between the controller and the fridge. All I need to do is pull some more length through the hole it comes through.   

 

[slief]

Prime rib is in! I couldn't wait! I had to run out yesterday and stopped by the butcher to look at Prime Ribs. I ended up bring home a 6 pounder and prepping it last night. I wrapped it in cheese cloth and put it in the fridge. I change the cheese cloth daily for the next few days. The plan is to let it stay in the fridge for 3 weeks. . Temps have been rock solid at 34-36* and humidity hasn't budged from 75%. It couldn't be working better. I will continue to update this thread as things progress. Dinner will be around February 7th!