I’ve been interest in curing and dry-aging meats for a while, but until I saw a recipe for duck prosciutto that could be prepared in a household fridge I had never considered the possibility of curing meat in my apartment.
I’ve got a separate post in the works for the specifics of curing meat, but for now I’ll just focus on the curing chamber I built over the weekend.
Mini Fridge, Big Potential
So I picked up this 2.7 cu ft mini fridge from Facebook marketplace for $40. I was going to go a size smaller, but this one ending up being perfect. It’s got plenty of space for me to hang larger charcuterie in the future, including lonzino and salami. I’m fairly certain I could fit a decent pancetta in there as well. I don’t think the smaller 1.6 cu ft fridges would have enough space after taking into account the additional electronics needed and unmovable freezer section.
So one of my main concerns with this fridge was the freezer section in the top right. With this type of fridge, the chamber is cooled by the freezer. This leads to two issues: the freezer can’t really be moved, and condensation.
Most meat requires curing conditions of 55-65F, with a relative humidity of 60-75% and circulating air.
Since the fridge will be cycling on and off at a much higher temperature than it was intended to hold, condensation will build up on the freezer box which increases the overall humidity inside the chamber. This ended up not being a huge problem, but I was worried I was going to have to add a dehumidifier.
I haven’t found a safe way to move or bend the freezer box yet without causing damage, so I’m missing out on that extra real estate for now.
If you get a frostless fridge (without a freezer box, cooled externally) for this purpose, you may need a humidifier to keep the internal humidity in the appropriate range for drying meat.
Taking apart the fridge really helped while cleaning. I used a 50-50 mix of vinegar and water in a spray bottle, and later went back over everything with all-purpose cleaner. The rubber seal around the door was the hardest to clean, and was not removable with this model. There was still some discoloration of the rubber by the end, but I was able to remove any mold that had been growing while the fridge sat in storage. Everything is very clean and smelling fresh now.
I removed the internal thermostat module and soldered some wires together so that the fridge would always turn on when connected to power. The fridge needs to be “always-on” so that the new digital temperature controller I added can do it’s job properly.
I also bought a wireless indoor/outdoor thermometer with a sensor that is kept in the fridge. With this I have an additional source to confirm that the internal temperature matches up with the settings of the temperature controller. They were within ~0.2F of each other, which works perfectly for this setup. The thermometer I bought also measures humidity, which is crucial to preventing bad mold from growing on the meat.
For now I’m just using my earlier sous vide temperature controller as a temporary setup until I get some other electronics wired up for a more permanent solution. I plan on adding a BME280 temp/humidity sensor (although I have a K-type thermocouple sitting around that could work too) with an ESP8266 for wireless monitoring and control. This will all be integrated in the back of the fridge, alongside the compressor and other electronics.
So far everything is working well! I’ve got some duck curing in there at the moment as a test. As I mentioned earlier, I was worried about the condensation from the freezer increasing the humidity too much, but so far the chamber hasn’t gone over 78% and typically stays at around 66% RH. I added a computer fan to keep air flowing inside as well.
In part 2 I’ll get more into the electronics and other modifications with some better pictures and lighting. Stay tuned!
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