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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => EQUIPMENT - Aging Cheese, Caves => Topic started by: Jearil on August 23, 2012, 05:11:33 PM

Title: My new custom controlled cave
Post by: Jearil on August 23, 2012, 05:11:33 PM
I've been reading this forum for a while now but haven't posted anything because I'm just starting to get into Cheese Making. I've made a few soft cheeses, but I really wanted to get into hard cheese. I knew that I would need to have a cave for this, so I decided to build one.

I'm a programmer by trade so while I could have just bought a regular temperature controller, I decided to build one instead for fun. I used an arduino as my microcontroller, and then a DHT22 temperature/humidity sensor to track temperature and humidity along with a PowerSwitch Tail 2 (a very fancy relay) for turning my cave on and off. For the cave itself I used a fairly standard chest freezer.

I put in some buttons for controlling the target temperature (and target humidity, but that's not hooked up yet). There's a 16x2 LCD that displays the current temperature and humidity along with the target temperature and status on if the cave is being cooled right then or not. I used 3.5mm audio ports on the box to plug in the sensor and control the power to the freezer. I designed an enclosure for the box using a combination of AutoCAD and DraftSight and cut some 3mm birch plywood on a laser cutter to make the box. The enclosure files took the longest of this whole thing.

The system is set to 55F with a 2.5 degree buffer. So when it gets above 57.5F the freezer turns on. It stays on until the temp drops to 52.5. The control box then won't allow the freezer to turn on again for at least 10 minutes (which shouldn't happen anyway). I may end up tightening the range. The trade off ends up being between consistent temperature and burning out the freezer.

So far humidity is staying pretty low. This morning it was 60% with just a bowl of water at the bottom. I'll try adding some cheese cloth draped in it tonight to try to increase it. There's only a single 2lb cheese in it so far, though I have plans later this week to try making a 6lb or so one.

This has been a really fun project for me. I know in the end it cost more than going with a commercial solution, but I learned a lot and made something quite neat. My plans later are to upgrade it to something where I can get statistical data logged to see how the temperature changes over time and how long the freezer is on/off for. I also want to use a lot of the same techniques to make a cheese vat/Sous Vide machine in the future.

(Oh, and the LCD screen is upside down in the one pic because I had first put it together wrong and thought it was funny so I took a pic. The final piece has it turned right side up I just don't have a pic of it right now)

Title: Re: My new custom controlled cave
Post by: bbracken677 on August 23, 2012, 05:18:32 PM
wow!  Very impressive! 

Nice job!

a cheese for you for technical creativity!  lol
Title: Re: My new custom controlled cave
Post by: BobE102330 on August 23, 2012, 05:49:42 PM
Nice.  I am not microprocessor literate, but appreciate the effort.

I use a microfiber cloth held up by bamboo skewers.  In my 3.5 cubic foot cave it keeps the humidity up to around 80%.  Cheesecloth didn't work nearly as well.  I've seen someone here using a humidity sensor controlled fan to increase the effectiveness.  Since you already have the sensor and microprocessor it should be trivial to add fan control to actively manage your humidity. 
Title: Re: My new custom controlled cave
Post by: Mike Richards on August 23, 2012, 08:00:21 PM
You've got a pretty cool setup.  I considered using an arduino to control my cheese cave, as well, but decided to see if I could just trick a window a/c unit first.  Since I was able to do that, I've stuck with it.  I'll have to move at some point, and leave the cave behind.  At that point, I will probably do something similar to what you've done.  I particularly like the idea of being able to program in specific temperature profiles I'd like to follow.  Not sure how much utility that will ever actually have, but I like the idea.

I mentioned this in another post, but I'll put it here for your consumption, as well.  If you fill your cave with bottles of water (or some other thermal mass), you shouldn't need the 10 minute minimum compressor rest constraint.  The compressor will run for longer periods of time (which is actually better for efficiency) because it has so much thermal mass to cool.  It will, however, also rest for longer periods of time because there is so much more mass to absorb the energy that causes the temperature to raise.  This will lead to slower temperature rise and drop.  I'm not sure how this affects affinage, but I presume slowly changing temperatures within a given range are better than rapidly varying temperatures within the same range.
Title: Re: My new custom controlled cave
Post by: BobE102330 on August 23, 2012, 09:26:54 PM
Hey Mike, did you notice the water bottles in my cave following your suggestion in the other thread?  Thanks. Works like a champ.
Title: Re: My new custom controlled cave
Post by: Mike Richards on August 23, 2012, 09:42:24 PM
I didn't notice before, but I see them now.  Nice work!  I'm glad they helped. 
Title: Re: My new custom controlled cave
Post by: Boofer on August 24, 2012, 12:21:16 AM
What, it doesn't talk?  ;)

Nice project, Colin. There aren't enough nerds on the forum. Welcome aboard!

Title: Re: My new custom controlled cave
Post by: Jearil on August 24, 2012, 01:19:41 PM
Ok, I have to try that water bottle trick this weekend. I only have a measly single cheese right now and the ranges are varying wildly. I noticed this morning that it was up to 62F for some reason. I don't think the freezer likes being empty.

I'll report back on if that helps my problem. Thanks for the tip.
Title: Re: My new custom controlled cave
Post by: vertlook on August 24, 2012, 06:30:03 PM
Nice setup, I am playing with Arduino myself.
What T/H sensor are you using? Any problem with the cable length?
Title: Re: My new custom controlled cave
Post by: Jearil on August 25, 2012, 11:43:09 AM
I'm using a DHT22 temperature/humidity sensor. You can get one at adafruit ( ( For cable length it's pretty easy. Since I wanted the unit to be detachable so I could leave the sensor in the freezer even when I took the box to update the software, I used 3.5mm audio jacks and just cut one end off an audio cable and soldered the wires to the sensor's wires. I would imagine you wouldn't want it to be too long in case the signal drops off, but my 6' cable works well enough.

So I'm having problems with my cave though. The control box seems to be working fine, but the freezer, which is brand new, isn't turning on the compressor and cooling down. It was at 75F last night. I had to put my cheese in a fridge. I unfortunately know a lot more about microprocessors than I do about freezers. Even just having the thing plugged in normally, not via my control box, doesn't work. It did work for about a day or two, but now it just gets slightly chilled near the top of the chest freezer but no where else. I have no clue what's going on with this thing but I might have to call to have it serviced or returned. A real bummer.

Otherwise the humidity has been fairly stable. I've even had to raise it a bit. I'm pretty happy about this because I had read a lot of people with chest freezers having issues with too much humidity. It might help that I'm in the California Bay area and our humidity is naturally in the 40-50%.

I put some water bottles into the freezer. But unfortunately until I get the compressor to work or get a replacement freezer I am once again without a cheese cave. Ah well.
Title: Re: My new custom controlled cave
Post by: Mike Richards on August 25, 2012, 09:37:59 PM
That's a bummer.  I hope you can get it up and  running (or get a new one...) without too much work or expense.
Title: Re: My new custom controlled cave
Post by: Jearil on August 27, 2012, 11:01:45 AM
Lowes came and took my freezer away and replaced it. So far the replacement is working just fine. Here's some updated pics of the control box and what's in the cave currently. I also made my first Cheddar over the weekend; Cheddaring process and all. Man that was a lot of work. It's still being pressed until tomorrow morning. I'm hoping to be able to crack it open sometime after January for a taste. I hope it comes out ok.
Title: Re: My new custom controlled cave
Post by: Boofer on August 28, 2012, 08:32:15 AM
Hey, I've got a Dutch oven just like that!  Same color! :)

Interesting choice for a pressing weight.

Thanks for posting about the Arduino controller. I was totally unaware. Back in the day I've crafted controllers using discrete CPUs (loved the Z-80) & ICs and burning fusible-link PLAs and Eproms. They've made it so much cleaner, almost a commodity, to put together a project. Sweet.