July 31, 2009 - 5:55pm
proofing box
I've read several places on TFL about hooking in an inline voltage thermostat to get the right temperature for proofing. Has anyone actually done this and if so how was it done? What i'm finding is that a heat (resistance) source has to be at least 2.0 amps. Is it any different than hooking in a light switch and is there a certain kind of digital thermostat.
Herb
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I bought one of these http://www.amazon.com/WIN100-Heating-Cooling-Programmable-Thermostat/dp/B000E7NYY8/ref=pd_cp_hi_2/178-2215542-8984221 and wired it to a socket with a 15W bulb. Then I place the bulb and thermostat on opposite sides of a cooler. I use different coolers, depending what size I need. Works great
Herb, I suspect you may have your electrical theory confused. If P=IE, then 2 amps of current on a 120 volt circuit would mean a 240 Watt lamp. That's far more wattage than you'd need for a proofing box. You could probably bake the bread with that much heat. The idea offered by BobS (I really like the thermostat he selected) works great. If you don't want to use a picnic cooler type of container you could build a plywood box (double walled and insulated if you want to go that far) but it's not at all difficult to achieve the goal of buiilding a proof box yourself.
So you don't have to cut and paste the link, here it is in a form you can just click:
http://www.amazon.com/WIN100-Heating-Cooling-Programmable-Thermostat/dp/B000E7NYY8/ref=pd_cp_hi_2/178-2215542-8984221
Thanks for the reply. I picked up a thermostat, installed it in a styrofoam box as mentioned in the site here from some time ago with a light socket and a low wattage bulb. The thermostat didn't function so I looked more carefully at the instructions where it said there had to a minimum of 2.0 amps. So I tried a 240 watt bulb and the instrument registered that it was functioning but the light did not go on. Instructions stated it was for baseboard heating. Looking at the site you sent me the type of thermostat is quite different. Not being all that knowledgeable about this stuff I guess I just picked up the wrong kinds.
Thanksfor the link. I guess I just blew a chunk of money.
Herb
Any cool, easy, cheap ideas for a proofing box that would be a little cooler than the environment? Say maintain ~60F?
:-Paul
Use BobS's idea but instead of a light bulb, cut a hole in the side of the box near the top and install a muffin fan in the hole, Control it with the thermostat and cut small holes on the opposite side (also near the top) of the box. Connect a funnel the exterior of the box, where the muffin fan is mounted, and link that by ducting to a bucket of ice cubes so the fan pulls in cooler air when the temperature goes above 60 degrees and stops pulling in air when it reaches that temperature.
For the technically inclined:
http://www.electronickits.com/kit/complete/peltier/ck500.pdf
SteveB
http://www.breadetera.com
I was thinking of trying out my cooler with an ice pack in it. Slightly different subject, but I was also thinking of using a wide-mouth thermos to keep my starter at 70 degrees.
--Pamela
My Cuisinart wine fridge turned out to be kind of a dud for wine since it really struggles to keep temps in the 50's F, but is great for SD starter control. It happily keeps 68F which is perfect for my stiff starter. If I were you I'd look into inexpensive wine fridges but stay away from Cuisinart (which was NOT inexpensive).
Summer
p=ie is for dc voltages and current. Here we're talking about AC, which alternates direction and isn't constant, so the formula doesn't work out to 240W as you might suspect. The actual voltage needs to be multiplied by .707 to account for the sinusoidal varitions, so 84V times 2amps gives you 168Watts.
You're absolutely right, doc; I forgot about the RMS .707 element for AC. But I'm pretty sure you'd agree that 168 watts is still far more wattage than you'd need to maintain the temperature for a good proof box.
done that. In the winter, my kitchen is a bit on the cool side, so I made my own proofing box.
I got a large old Coleman cooler, fitted it with a line voltage thermostat that's made for greenhouses (look here: http://kkontrols.com/ ) and use a heating pad for the heat source. I place the heating pad on the bottom of the cooler and put a shallow pan of warm water over it. I built a shelf to sit a few inches above the pan, and I proof the dough in a container on the shelf.
It works really well for a Rube Goldberg appliance.
Can anyone clarify the apparent discrepancy between the thermostat that BobS used and the one that Caviar bought? I ordered the one from the link that was posted and it appears I am in Caviar's situation. The thermostat won't plug into a "standard" receptacle. The ground prong is round and the outlet for the ground prong is flat on one side, so it doesn't fit. I would appreciate and additional information.
Thanks
Hi TomH,
I'm not sure I understand your question, but let me explain a little about thermostat types and perhaps that will help. I should note that I am in the US, so this discussions uses US voltages for example. YYMV outside the US.
There is a lot of confusion because there are two types of thermostats that appear to be similar (and are sometimes called the same things in listings and at the store) but are quite different.
One type, often called a Line Voltage Thermostat, is used to control electric heat and is usually (but not always) wired in place. In a house, sometimes these appear on the electric baseboard, and sometimes on the wall. These thermostats have two important characteristics:
These Line Voltage Thermostats do not work for controlling light bulbs, fans and small heaters. It is often hard to figure out exactly what the thermostat is from the description. Here's a line voltage thermostat:
http://www.amazon.com/Honeywell-TL7235A1003-LineVoltPRO-Non-Programmable-Temperature/dp/B000GGPMZ6
Note that the detailed electrical parameters of the thermostat are not listed - you have to read the back of the package.
A good clue to finding a thermostat that will control a light bulb is to look for one that has an electrical plug that fits in your wall outlet and a jack into which you can plug the light bulb. There are a couple of types in this area:
Here's the link to what I bought again for reference:
http://www.amazon.com/WIN100-Heating-Cooling-Programmable-Thermostat/dp/B000E7NYY8/ref=pd_cp_hi_2/178-2215542-8984221
I hope that helps. I don't quite understand your comments about plug, etc. If you elaborate I may be able to help.
Bob
Bob,
Thanks for your very complete answer, and sorry for my very vague question.
I had ordered the thermostat that you reference in your post. When I went to plug the unit into the outlet I was using to power my proofing box it didn't appear to fit. I assumed that it was because the third "prong" on the back of the unit, the ground "prong", was round, while the ground socket on the outlet was more U shaped, that is, flat on one side. It turned out that it was just a very, very tight fit and I had to push very hard to get it in, but in it did go. Color my face red.
Thanks again for your suggestion on the thermostat, I'm looking forward to using the proofing box this week-end.
Tom
Cool. Sometimes, in life, you just have to push a little harder.
It's normal for the ground socket has that flat side and the plug to be round. Maybe it's to give it a little wiggle room for removal.
I did have one of those thermostats fail within the warranty period. I looked up the manufacturer on the web, exchanged a couple of emails, and had another one by second-day Fedex.
My sourdough life greatly improved after I built that box. I live in the Northeast, and the house is never warm enough for my starter a lot of the year. The box, combined with overnight retardation,has allowed me to make consistently good (maybe even excellent) bread on my schedule.
b
I can relate to the too cool conditions, living here in Minnesota. I'm excited about how this will change my life.
Tom
Can't tell from the Amazon listing. Is the temperature sensor built into the unit or is it wired so it can be separated?
Looking for something to control a refrigerator to use as a retarder.
thx
dan
It can be separated, but only by maybe an inch or two.
So I am currently using a plastic filing box. I have a 40 wat light bulb hanging down. It is very clumsy to use. I am constantly knocking the bulb trying to put my bulk proofing bins. These bins go in and out 3 times during a normal bake. Here is the concept for the 2.0
I want to use White sheathed Melamine. I want to build the box to take advange of the height under the cabinets (One reason why its clumsy is because I cannot raise the lid all the way open). This way the cabinet will look like it belongs in the kitchen.
So using the the new wood box I would like to find a low profile heating source. I would prefer a flat radiating heating source. Has any one used a Terarium Heat source like the ones on this list
http://www.amazon.com/s/?ie=UTF8&keywords=terrarium+heater&tag=googhydr-20&index=aps&hvadid=4031764601&ref=pd_sl_6sh95b0cdp_e
Does any one else have a recomendation for a good blanket stle of heat source.
So to finish my plan I am going to use cooling racks as shelves when I want to proof dough and then remove 1 of them when I am profing my starter. I will also be making tight fitting doors with weather seals to keep draft out and warmth in.
If any one has any good suggestions I would appreciate it.
Proof boxes that provide humidity control, is covering the bread during the proofing stage necessary?
I assume the answer is no since the humid environment, with the addition of the air flow, will not dry the bread's surface area. Is this correct?
Here's what I had ordered for my original proofing box design. It's a bit pricey, but will control both heat and humidity sources with a combined output of up to 1000W. It will also display heat and humidity. After I ended up buying a used professional proofing cabinet, I use this unit to control the accuracy of that cabinet while using it (it only has a 1-10 dil to regulate temp and humidity).
It looks like it's sold out right now at the source I linked to, but a search for "Zoo Med HygroTherm" might deliver additional sources.
Stephan
Ted,
it totally depends on your doughs and how serious you are:)
A bowl of boiling water will give you plenty of humidity - I actually use the "microwave and bowl of hot water" method when I make just one loaf.
If you have a larger proof box or need to proof your breads longer, it might be nice to be able to monitor the humidity.
Like I said, it's not necessary, but definitely nice to have.
Stephan
This Goodwill bought $5 invention keeps my oven set at any temp between 90* and 150*F.
http://www.youtube.com/watch?v=ToneZn4Lhyc
Enjoy,
stU
Mozart, mine is just a wine cooler, with a heating pad in it, so I don't think pictures would help much. Is general, if you want to increase the humidity, put in a cup of boiling water, put a sponge in the water if you want the humidity even higher. Some of the posters above try to avoid excess humidity, so they might use a smaller glass of water. I am usually proofing my starter to get it going, so it isn't there long enough to make much difference in humidity.