How to build your own curing chamber
2019 Kjell
If you are interested in dry-aging meat or the making of Italian and Spanish charcuterie then having access to a curing chamber should be a top priority.
There are many ways you can build a curing/aging chamber. I will describe what I have done and what works for me. My setup is primarily used for whole muscle type of charcuterie, salumi and secondary for wild game aging. The chamber is used year-round but in the fall the focus is shifting at times towards aging wild game.
The downside to my setup is that it’s too small to dry age a whole elk or moose. For elk, I would have to make space and still only have room to dry age the hind legs. The rest would be wet-aged in vacuum-packed bags.
Two deer hind legs that are aging together with salumi that are dry curing: big salamis and two coppas. The salamis are huge which tricks the eyes in this picture to believe the hindquarters are small … they are not :)
The Curing Chamber
My preference is to use an upright, frost-free freezer. A frost-free freezer has a few advantages to other fridges/freezer options.
The frost-free freezer will be better insulated than a frost-free fridge. Better insulation means fewer compression cycles to keep the temperature range and less strain on the compressor.
The frost-free freezer is using extremely cold air-flow, not a cold plate, to cool down the chamber space.
Don’t use a chamber with a cold plate. A cold plate cooling system will create condensation, up to the point where it might “rain” on the products.
The circulation fan that is pushing the cold air will also work as a dehumidifier so that excess humidity is avoided. I have a dehumidifier installed in the chamber but it’s rarely used.
Using a freezer instead of a fridge comes with the benefit that it can act within the 3 roles of a curing chamber, fridge, and freezer. Using an external temperature control that turns on and off the freezer can with a couple of button clicks transform the unit to what best suits your needs at the moment.
If the external temperature control unit breaks and the charcuterie is frozen then do not despair. Just replace the controller and go about your business. Salumi is resilient towards being frozen. You can resume the curing from a previously frozen piece even if it is not ideal as it will slow down the process.
Do use a temperature warning system. Even if you check on your charcuterie daily the audible alarm for a too warm or too cold chamber can save you time, money and worry.
Do you see that tiny device hanging next to the deer quarter on the picture above? It measures and estimates the aging of meat according to the C-Day Grade formula. We import and sell it here at TasteOfTheWoods.com, You can check it out here
TEMPERATURE AND HUMIDITY CONTROL
The desired temperature range is best achieved with a temperature controller. It is a unit that measures the temperature using a sensor inside the chamber and which can turn on and off the power to the freezer. I am using the Inkbird ITC-308 which I’m very happy with but there are other options available.
The Inkbird is connected to a power outlet and the freezer is connected to the Inkbird. When the temperature in the chamber hits an upper threshold the power to the freezer comes on. The power stays until the temperature has dropped past a lower threshold. To avoid having the compressor running too many cycles the Inkbird can be adjusted with a compressor delay. I keep the compressor delay to 10 minutes. The controller setup is very easy and after checking the manual for a few seconds you will feel comfortable using it.
The desired humidity range is also best achieved with a humidity controller. The humidity sensor will be inside the curing chamber. A good humidity controller will have both a dehumidifier and a humidifier electric outlets. When the humidity is too high the dehumidifier will turn on and vice versa. I am using the Inkbird IHC-200 and it is so far more reliable and long-lived than another model that I tried.
TEMPERATURE
Curing: For curing meats and salamis I keep the temperature at 46.5F (8C). Many keep the temperature at 50F (10C). My choice of slightly colder temperature makes the drying a little bit slower but I hope it develops flavors better.
Dry-Aging: I both dry and wet age meat. Meat that you can find in my curing / dry-aging chamber in the fall is from deer, elk, rabbit, ducks, and squirrel. My recommendation is to keep the temperature between 37.4F - 41F (3-5C). This range will give good progress on the aging progress with very slow bacterial growth. For aging meat it is temperature AND time that matters. Just “time” in cool temperatures gives wildly varying results. Please check out a previous article regarding how to measure aging so you can tell when it is done or extend the day grades when needed.
You can go colder or warmer but you should avoid having it reach as low as 32F (0C) or higher than 50F (10C). Remember that it is temperature and time that are the main factors for aging meat.
Avoid having the animal’s core temperature go below 50F during the first 24h when rigor mortis sets in and is released. If it gets too cold you will get muscle cold shortening and end up with drier and tougher meat.
HUMIDITY
Curing: For curing meat and salamis I prefer 75% relative humidity.
Avoid too high humidity as that will cause excessive mold, maybe even unwanted mold types, and even sticky yeast buildup on the surface.
To keep in mind: You want the charcuterie to dry slowly and without risking case hardening. Case hardening is when the outside dries too quickly and forms a hard shell. The case hardening will block moisture to escape and can spoil the product. Case hardening is caused by too low humidity or too much airflow.
Dry-Aging: I consider the sweet spot to be 75% relative humidity.
To keep in mind: At a higher range (85 - 95%) you risk microbial growth and spoiling the meat. At lower range (55% - 70%) you risk losing too much weight and will have to trim excessive amounts off. I believe you can also get case hardening (see below) which can ruin your meat. Please note that the hard “leather skin” trim does not have to be discarded. I have used it for chilies and slow cooks with excellent results. Keep in mind that the trim will be “thirsty” as it will rehydrate.
Duct tape for the cables and command adhesive strips for the humidity, temperature controllers and power outlets.
CALIBRATION
Every 6 months or so I make sure to calibrate the humidity and temperature sensors.
The humidity sensor can be calibrated in a jar with water saturated salt - the humidity should read 75% relative humidity.
The temperature sensor can be calibrated in an ice water bath. Put the sensor in a sealed plastic bag as it isn’t to be in direct contact with water and then submerge it. After a few minutes it should read 32C.
If the humidity is off the expected 75% or the temperature off the expected 32C then calibrate your inkbird or sensor-of-choice according to the manual.
A video that shows these steps can be found here: https://youtu.be/AI9jC_wXd1k
Installation
With my choice of the upright, frost-free, freezer there was no need to drill through any wall or any such permanent damage to the freezer. The power cables fit nicely at the bottom of the door, near the hinges.
The smaller sensor cables could probably fit anywhere but I wanted them a bit high to avoid the airflow from the freezer. To further decrease funky sensor readings I placed a paper above the humidity sensor. This seems to decrease weirdness as it blocks some of the airflows that can mess with both the temperature and the humidity readings.
The sensor cables are taped and almost ready. Later a thick paper got placed above the sensors to stabilize sensor readings.
Easy to clean Humidifier a Dehumidifier and a quiet low, power fan is all that you need for good air flow and controlled humidity level.