Monday, January 7, 2013

Temperature Controller

I spoke previously on here about adding a temperature controller to my Black Garlic Oven design, and appreciated CubeConvict's recommendation of the STC-1000. I found this general use controller intuitive in ways, though the software interface is somewhat erratic in its utilization of its buttons.

To illustrate this, consider the hardware connections on the rear of the unit. The connections are all screw terminals, with pairs for power, sensors, cold and hot, in that order. I found this configuration straightforward and appropriate the the application. The software interface, however, offers challenges. The power button is labeled with a standby symbol, which alone is confusing. Furthermore, consider the way to change temperature. On the main screen, one holds the "S" key for 3 seconds, selects a menu item using "S" and then adjusts the setting by holding "S" and pressing "Up" or "Down". When the desired setting has been reached, one presses the Standby/Power button to commit the change.

Thankfully, the unit required very little adjustment. For housing, I purchased a PVC box (As pictured in this MakeProjects post) and added a power outlet and binding posts for the sensors. After splitting the plugs on the power outlet, the unit allows me to simply plug the oven into the "heat" plug.

The binding posts and banana jacks purchased from RadioShack, with the binding posts being advertised as "insulated" (though it would take a far stretch of the imagination to consider these meaningfully insulated). The binding posts are screw-on, and I drilled holes to attach the power outlet. The STC-1000 has mounting brackets included that secure it to the lid. I used disconnect terminals inside to attach the power cord to the controller and the outlet (the electrical tape wrapped bit connection the end of the power cord's sheathing), and spade terminals to provide power to the outlet.

Everything fits easily inside the 4"x4" PVC box that I purchased from my local hardware store. To secure the power cord inside the box, I put two zip ties on the cord and heat shrink wrapped them with a glob of glue inside the tube.

Part of the beauty of this controller is that, in an arrangement such as this one, it can be used to control both heating elements and cooling systems (such as an AC or a chest freezer), allowing it to be used for any application between -50°~90°C. I will likely use the STC-1000 for many other fermentation chambers in the future.

Update (2013-01-07) - Circuit Diagram:
A barebones illustration of the circuit with a heating incandescent and cooling appliance plugged in.

Saturday, January 5, 2013

Garlic Amino Salt

Taking a cue from Chalt, I decided that I should like to make an amino heavy salt. I have previously been led to believe that the flavor advantage of sea salt, particularly highly regarded sea salts such as sel gris, fleur de sel and varied other examples, is the mineral and amino content imparted by the brine from which it is collected. My intention in this case was to create a reduced salt with far-increased amino content, intended to be used in a similar way to soy sauce, but without the addition of liquid. I'm calling this salt "Garlic Amino Salt", as its ingredients are sea salt, alderwood smoked salt, black garlic powder and minced preserved garlic.

As this is a small-batch experimental recipe, I started by adding 250 mL of Spring Water to a medium saucepan over high heat. Once the water started boiling, I reduced the temperature to medium, and added 50g of an ordinary, mid-price Sea Salt.

I then began attempting to super-saturate the solution with sea salt. After adding 25g more salt, I discovered that the solution was too thick, and added 100mL more water. The solution at that point seemed too thin. I then added 3g of smoked salt and 5g of sea salt, and started adding water in 15mL increments. After 5 such increments, I decided that the solution was appropriately dilute as to be supersaturated at boiling. I then added the black garlic and minced garlic, boiled for 2 minutes more, and poured the mixture through a plastic filter I purchased online into a 2.2qt Pyrex baking dish. It was then placed in an oven at 275F, as shown.

I checked the solution at 15 minute intervals, observing the drying taking place from the outer rim of the dish inward, as illustrated in the following sequence. Note that significant precipitation happened in the first 15 minutes of the process.

After 90 minutes of such, I found that the solution had dried into a loose cake. I removed the dish from the oven and stirred it using a silicon spatula. The resulting aggregate was semi-moist, with pockets of completely dry salt interspersed. I decided that the mixture could use more drying and placed it back in the oven for another 30 minutes.

At this time, I removed the salt from the oven and stirred it up once again. It had become dry throughout, excepting a few small, moist clusters that nonetheless crumbled between my fingers. Tasting the new salt, it was intensely savory, with a significant but far-reduced saltiness from the original sea salt. I think it would work well as a salt replacement at anywhere from 1:1 to 1:2.5, for any recipe that the cook wanted to make more savory and wouldn't mind including black garlic flavor.

I believe this recipe would be helped by the inclusion of a vacuum hood for the reduction of the salt, coupled with a significant reduction in drying temperature. When using a vacuum hood, however, I would double the black garlic content and remove all minced garlic. The inclusion of some (5g on the light side to 15g on the heavy side) dried roasted garlic would be preferable to minced garlic in this case.

This experiment had an unexpected but not altogether unwelcome side effect. On a first attempt, I accidentally added the garlic and black garlic early, and decided I should start over. Not wanting to waste perfectly good black garlic, I put the failed recipe in a Pyrex loaf dish in the oven, without filtering, and the garlic mixture reduced down to a thick paste. I intend to put it in a yet undetermined amount of olive or canola oil, and use the result as a cooking paste or condiment.

Experimental data was transcribed to a text file, available on Google Drive.