School of Sourdough

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Reinventing the Reinvented

So here I was, camped on the farm in my caravan, waiting for things to happen with the dairy shed, which will become my classroom and bakery when it’s finished. I had all my bakery gear packed up. I didn’t have a bakery to put it in, but I did have the trailer, and a space in the shed where I could temporarily set up some of my equipment - the mixer, a fridge, a bench, and some ingredient storage shelves.

All I had to do, I figured, was to permanently install the traveling oven I took with me on the Tour Down South into the trailer, get the Coolgardie Cooler working better, and create a proofer on the trailer. Then I could bake at least a few dozen loaves at a time. This would be enough to make ‘a bit of dough’ while I was waiting for my new home to be built.

So I’m reinventing the reinvented, repurposed and recycled trailer. First it was a six by four, then it became my bakery shop and bread transporter, and then it became a mobile classroom and boudoir while I traveled the country, and now it was to become my semi mobile temporary bakery. I’m calling it the Bush Bakery II.1.

Getting the Cooler cooler

I figured that the issue with the Coolgardie Cooler was ventilation - it simply didn’t move air around inside enough for there to be any evaporative cooling effect. I decided to improve the ‘Coolgardie Coolroom’ by adding solar driven frictionless computer fans to the coolgardie screens, so that air would circulate quickly and constantly through them, and then inside the box. I installed a couple of vents to the outside of the trailer to assist with taking in air.

I had used a similar fan system in the Bush Bakery Mk I, which was adequate for holding dough cool for a day or so. Tried and tested technology, even less than perfect technology, is always a good option for me.

I purchased a 5V battery which could invert to 12 volts, and a solar panel which could be attached to the roof. I was aware that I was moving away from my ‘third world simple’ approach, which had guided me throughout the build of the Bush Bakery Mk II. Frankly, this approach had failed me with regard to the Coolgardie Cooler, so it was time to enlist some slightly more sophisticated solutions. Despite my extremely limited ability with regard to electrical wiring, the fans work very well. They will run for about 3 days without wearing out the battery. When the battery is plugged into the solar panel, running the fans rarely lowers the charge of the battery. It can be raining and cloudy for days on end and there will be no interruption to the ventilation inside the cooler.

Putting some vents into the Coolgardie Cooler

The screens in the side of the cooler were made from recycled exploded clay pellets wrapped in shade cloth, chicken mesh and hessian. I ran bleeder hoses through them so the clay could be moistened. There are hose outlets fitted so I can just plug in a regular garden hose to refill the screens with moisture. Once the screens are moistened, the fans can achieve about 5 degrees cooler than the outside ambient temperature. This isn’t enough to keep dough cool, but it shows there is an evaporative cooling effect. In future possible versions of this technology, I think I would make a lot more air move through the screens, as well as create a better plumbing system to hold water evenly through the vertical surface of the screen. For now, I have to add ice to the system to really make it work properly, particularly in summer. When there is ice in the cooler, as well as moisture in the screens, the Coolgardie Coolroom can bring the ambient temperature down by as much as 20 degrees below ambient. This is enough to keep dough cool for many hours at a time. I use repurposed plastic bottles filled with water and frozen as my ice supply. As long as there is a freezer to supply ice, I can run the cooler continuously.

Interestingly, making ice uses very little energy. If you have a domestic fridge and fill the freezer section with bottles of water, the thermal mass created as the bottles freeze actually reduces the amount of time the motor needs to run to keep it cool. I wonder if fridges harvest the cold from the freezer section to cool the fridge section - and if they don’t, why don’t they?

I gotta say, I reckon I’ve now got a ‘cool’ cooler. I’d given up on it during the Tour Down South, but with this new tweak it has become a useful piece of equipment. I can see myself modifying it a bit more down the track with the addition of more fans and more fins (timber fins to rest transit boards full of dough). Its capacity is currently just a trifle small, but I have plenty of space which I can use.

The Bush Oven installed on the trailer.

The Bush Oven becomes a weapon

Setting the oven up on the trailer in a permanent fashion was something I had been wanting to do since I was in WA on the Tour Down South. On the road, despite having all my tools on board at the time, it was just too difficult to do from a practical perspective. Now I was parked here in a paddock, it was easier. I designed the space for the oven to be postioned on the trailer to have an adjoining insulated box, similar in shape and size to the Coolgardie Cooler on the other side of the trailer. This would be warmed to become a proofer via a galvanised sheet of steel attached to the side of the oven.

The oven itself became wrapped in brick on five sides when I put it on the trailer. This was about a 400% improvement on the level of insulation I had when I set the oven up on its stand. This was the primary reason for putting it on the trailer. Theoretically, the oven would now become a very fast, well insulated baking weapon.

The first attempt at mounting the oven on the trailer was partially successful - it certainly baked a whole lot better than it did when I used it on the Tour Down South. The adjoining proofer was also a success. While it couldn’t create moisture within the box, it heated it very gently as the oven warmed up. I soon added a spirit burner stove with a saucepan of water to create steam. The proofer was very well insulated, and one load of water boiled at the start of a bake was enough to keep the proofer moist for a whole bake.

A Woodfired trailer?

My first serious bake using this setup was for a massive 90 loaves, which was during a 300 series workshop. While the oven held up to a continuous bake environment, a few hours after the bake was done I noticed a bit of smoke coming out of the trailer. The trailer actually had caught fire, and was well alight by the time I could get a hose to it!

Fortunately, I was able to put the fire out (thankfully I had a student, Jerome, hanging around after the workshop, who had a lot of patience and common sense - without him being around, I reckon I would have lost the trailer to that fire. Thanks Jerome!). It took a few hours of hose work to get to the seat of the fire, and to totally drench the trailer so it wouldn’t start again.

Adding a bit of fire blanket…

The next day I took the oven out of the trailer, and found that it had burned through the timber ‘floor’ below it. There was already 3 inches of brick under the oven, so I wasn’t expecting this brick to get so hot! I re installed the oven, this time with lots of fireproof insulation and more brick.

At the time of writing, I have re installed the oven a few more times, as I’ve built up my baking practice again. Each time I’ve refined the thermal setup. It’s now wrapped in lightweight concrete, brick and thermal blanket. And it is truly a baking weapon. It holds six loaves at a time, and can pretty much continuously bake an average of ten loaves per hour for as long as there is dough to bake. I rate this oven highly in my history of bakers’ ovens. I’ve probably baked in a dozen different types of oven over the years, and while this one doesn’t have the capacity of some others, it is great fun to use. The baker is working pretty constantly while using it, but for some reason it’s just very pleasant work. I’ve worked bigger ovens with much bigger throughput, and sometimes these ovens seem sluggish by comparison. This one is a little racing car! It requires constant attention, and can easily burn off the track, but if you keep an eye on things it goes very fast. It’s my pocket rocket.

The entire setup, the Bush Bakery Mk II.1, is also a baking weapon now. It’s very easy to control the bake, with a solar coolroom, a proofer powered by the oven, a dough area and ingredient storage all on board. I haven’t mentioned my new dough box, which is finally finished as well. It’s only used in classes, but it’s a great tool for making up to ten kilos of dough at a time. This piece of kit qualifies for another blog post! I truly now have an off grid bakery.

And now?

I’m currently in the process of doubling the output of the Bread Subscription Service. The subscription model is great because I can control growth. I take on new subscribers in a fairly planned way, in lockstep with the production capability of the bakery. The Bush Bakery Mk II.1 can comfortably bake 60 or so loaves in a session. This will be enough to keep things cashflow positive while my proper oven, Luna, gets refurbished.

My aim is to have a comfortable capacity of 100 loaves a day when the Steady State Bakery (see previous blog post) is properly functioning. This will be once again utilising my big girl, Luna. She’s currently having a rebuild by my erstwhile oven collaborator, Craig Miller of Aromatic Embers. Our expectation is that Luna will be a faster, steadier oven than she was. We’re adding a lot more thermal mass to her, as well as redoing the baffle system, the doors, and we are installing a bunch of cleaning access tubes to easily de soot her. I’m pretty excited about all this, and getting more excited as she nears completion.

As I write this entry, the dairy shed has internal walls built, some of the new ceiling done, a couple of doorways ready to have big glass doors put in, a new verandah roof over the back. The plumbing is half done, the wiring in place, and some of the insulation installed. There are soon to be two tradies working on the job, so it’s expected progress will hasten.

I do look forward to having my proper oven back, when the classroom and bakery in the dairy shed is finished. My life has felt like it’s on pause for the past six months, if I’m honest. The classroom section is getting done first, so should at least be ready in time for the next pro Sourdough 300 series workshops in May.

Subscribe, survive and thrive!

For now, I’m quite happy to bake a little bread each week for subscribers. The number of loaves baked and sold holds nice and steady. There is very little wastage. There will be growth, but in a very controlled way. Eventually 100 subscribers will be on board, as I believe the Steady State Bakery can handle these people’s total bread requirements fairly easily when it is finished. Currently I’m baking once a week, but I believe there could well be demand for another baking session or two in the schedule in the not too distant future.

Beyond this, I’m anticipating the dairy shed will be workable. Hopefully the growth of the subscription system will coincide with the work on the bakery and classroom here.

Watch this space for more about the new dairy shed, which will soon by my bakery and classroom, as it develops.

If you live in the Newcastle/lower Hunter region and would like to learn more about the subscription service I’ve now set up, here’s the link!