The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Simple Baker Trick: Proofing Box

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BobS's picture
BobS

Simple Baker Trick: Proofing Box

Flour, water, salt, time, and temperature. The right combinations of those variables, plus technique, make good bread.

Along with a few simple tricks.

I've learned how to make pretty good bread from this forum. This is the first of a set of posts describing a few of the things I've learned. Maybe they will help somebody new.

Here in New Hampshire temperature can be a problem. Like this week when the overnight low was -6F and the temperature in our kitchen was 55F. Yeast growth is really dependent on temperature and there is a happy zone in the 70-80F range. A proofing box gives me the control over temperature. There are several threads on proofing boxes on TFL. and there are commercial products. I made one, mostly with stuff I had around the house.  It was one of the things that made a big difference in my ability to make consistent bread. Here it is in pictures.

I started with a cooler we had in the basement:

Any size will do, as long as it is 'big enough'. Then I added a 15W light bulb and socket, and a thermostat. Nothing fancy, just shoved it all in there. The extension cord coming out of the box is flat, rather than round, so it is not too badly squished. The light bulb could probably be smaller wattage. You do want it some distance away from the thermostat.

That's Earlene, my starter Fred's love child, bubbling in the middle after a warm and pleasant overnight stay. The thermostat is a Lux Pro PSP300. I got mine from Amazon:http://www.amazon.com/LuxPro-PSP300-Programmable-Digital-Thermostat/dp/B0032JUG46/ref=sr_1_2?ie=UTF8&qid=1359256101&sr=8-2&keywords=lux+pro+psp300.It's a little expensive, but it works well. I think their WIN100 model, which is a little cheaper, would work too.

I can also fit a proofing bucket for bulk fermentation in there:

Cambro buckets work very well for bulk fermentation. Make sure you get yours from a local restaurant supply rather than a 'bread enthusiast' web site: mine cost $6.

That's Hamelman's Five-Grain Levain, more or less, in there.

I usually retard my sourdoughs, for better flavor and scheduling. But sometimes I do the final proofing in the box. For that I built a little stand that lets me stack bread pans or bannetons.

The box is tight enough and the loaves are wet enough to create a nice humid atmosphere inside without the need to introduce additional humidity.

The thermostat works for both heating and cooling. Sometimes I use it to control a little portable electric cooler (which doesn't have a thermostat) when the fridge is full and I need to retard some dough.

Bread runs on its own schedule. A proofing box help it conform, to some extent, with yours.

 

Comments

cranbo's picture
cranbo

Nice job on the DIY. 

I'd been eyeing one of those thermostats for a while. 

 

Janetcook's picture
Janetcook

Great proofing box. I made one last year when our temps. got too low and my halogen lamp couldn't keep up.  Made a big difference and I love it.  

Janet

isand66's picture
isand66

Great job and thanks for sharing.

One question; how long does it take to get up to 70 - 80 degrees in your proofing box?

I'm curious as I have 2 coolers I could use but I think they are both bigger than yours.

Also, what kind of make and model cooling fan did you buy?

Thanks,
Ian

BobS's picture
BobS

I've never measured how long it takes to warm up. Of course it depends on how cold it was to start. I would guess maybe 30-40 minutes to come from the 55-60 it is in the basement right now to 78 or so. Once it gets up to temperature it stays there. If I'm using it for bulk ferment or final prooving loaves (and I have enough presence of mind) I might turn it on an hour before I need it. When bulding a levain for 12-14 hours overnight I often put the newly-mixed levain in the cold proofing box, turn it on, and go to bed. The electic consumption (15 W with a low duty cycle) is minimal.

By 'cooling fan' I assume you are referring to my comment about using the thermostat to control an electric cooler.  I had an earlier version of a cooler like this one: http://www.amazon.com/Igloo-Thermoelectric-Cooler-Mercury-40-Quart/dp/B001JT5QAK/ref=sr_1_2?ie=UTF8&qid=1359294365&sr=8-2&keywords=igloo+electric+cooler (I don't recall paying nearly that much, but it was a long time ago.) These 'electronic' coolers use a semiconductor material rather than a compressor to cool; they will cool to a fixed offset from the outside temperature - typically 40 degrees or so. That means they can get too cold for retarding dough, so I use the thermostat in cool mode to cycle the cooler in the same was as I cycle the light bulb in the proofing box.

isand66's picture
isand66

Thanks for the info Bob.  I might just have to put one of these together.  I usually bulk ferment my doughs but once in a while like now I'm doing some English muffins so I'm letting it sit at room temperature.  It's about 65 degrees in my kitchen so I moved it to a bedroom where it's warmer. 

Regards,
Ian

homebythelake's picture
homebythelake

Hi Bob,

               Thank you for sharing.  I am a lurker at this site for a long time.  After reading your post, i think it's about time that I should start to share, too.......
Here is my DIY dual temp controller . 

This is my Proofing  box, very simlar to yours.  It really helps me a lot in fermentation , specially at the cold winter in WI.

and this is my second try of this 100% WW desem bread. With the help of the proofing box, I am able to control the final proofing temp for this bread at 95F (I also add a cup of hot water, and put it on the top of my heading pad to increase the humidity)

From the crumb shot, you can see I still need to work on my shaping skill (a big air bubble at the bottom of this bread  :(. ) .....  but overall, my family really liked this bread.

BobS's picture
BobS

Nice.

As an engineer I'm intrigued by your controller. Can you provide details?

Thanks

b

BobS's picture
BobS
carblicious's picture
carblicious

Thanks for sharing in detail. Very helpful for those who want to build proofing box.

varda's picture
varda

I think that's the simplest design I've seen and with parts reusable for other things.   That one is even simple enough that I could put it together.   -Varda

homebythelake's picture
homebythelake

Hi Bob   :

   I am glad that you had found the STC_1000 from Amazon. I purchased mine via Ebay with a better price. 

Hi Varda: 

Since I had "zero" knowledge about wiring and how to assemble all the things together, I got the help from internet and decide to be a 100% copycat, so I just simplely copied the list which I need from his site (http://imgur.com/a/5i3Lm) and purchaed all of them from local hardware store. With the help from youtube (http://www.youtube.com/watch?v=30TvX1Zz1-Y ), I learned how to wire STC_1000 with my hot/cold devices. 

H