GroundLevelCoffee

My mind continues to ponder some form of Stir Crazy/Turbo Oven roasting. Turbo Ovens are available in Aus. Prices for new TO’s range from around $80 up to $300. What’s the difference in build, function or quality? No idea. Funnily enough the new ones I’ve seen for $80 (in a reputable whitegoods store) go on eBay.com.au for $120+. One sold yesterday for $150! Ahhh, the rigours of the open market.

And so half of the equation - the top half - is fine. A Turbo Oven capable of heating to around 250C can be had for $80. But the bottom half of the equation - even the denominator?

Stir Crazy’s aren’t currently distributed in Australia as far as I can tell. I’ve emailed West Bend enquiring about their availability and will report back in due course. In the interim my brain is cogitating on various means of stirring the beans. So far the ideas have included:

• Record turntable
• Microwave oven turntable
• Attaching a motor to the underside of a large saucepan or frying pan.
• A potters wheel
• Manual agitation (don’t think so!)

I’m not electrically or mechanically ’skilled’ and so anything that involves drilling, wiring, moulding, bending or attaching can be a challenge. A few challenges ahead.

Having completed nearly 380 roasts in a little over two years, I have a swag of statistics regarding batch sizes and roast costs. My two poppers were comparable in cost to the XU1 heat guns, but completed less roasts each and, at a smaller batch size, end up costing about three times as much per roast kilo. The stats are:

Poppers: 57 roasts for 4.6kg giving average batch size of 81 grams for a cost of $8.65/kilo of greens roasted.

XU1 Heat Guns: 77 roasts for 15.3kg giving average batch size of a little under 200 grams for a cost of about $2.60/kilo.

Ozito Heat Gun: 57 roasts for 15.1kg at an average batch size of 264 grams at a cost of $2.65/kilo.

Imex: 187 roasts totalling 28.5kg at an average batch of 152 grams and a cost of $7.00/kilo.

And so a Heat Gun is the cheapest per kilo of roasted greens (around $2.60), followed by a long way by the Imex ($7.00 and dropping with every roast); with the popper a short way back at $8.65.

As a rough estimate, assuming a roasting drum and BBQ is good for 10 years at one kilo per week (my standard usage plus additional gifts, etc), the numbers work out at around the same price as a Heat Gun per roast kilo. BBQ roast is, say, $750 up front for 500 roasts, then about $1/roast for gas equals $2.50/kilo. More roasts of smaller quantities mean the numbers wash out at around the same.

I haven’t crunched the numbers for a SC/TO setup, but would expect something around $1.50 to $2.00 per kilo. $200 setup good for 3 years at 1 kilo/week equals $1.33.

But it comes down to more than the numbers:

• Ease of use
• Ease of profiling
• Quality of the output
• How well the roaster’s standard output is matched to estimated or likely usage

All good fun.

My progression through various coffee roasting methods continues. My first roaster (well, first two actually due to a melt-down) was the popcorn popper. I suspect many people now into roasting started there. These days there are a number of low-cost, easy-to-learn, fairly easy-to-get-decent-results-from methods such that the popper may not be the roaster of choice for so many beginners.

After my second popper’s case started melting, I figured I needed something a little more durable. I opted for a Caffe Rosto or Imex CR-100 roaster. It’s a fluid-bed roaster (ie. hot air) with a batch size in an unmodified roaster of around 160 grams. My Imex has now down around 180 roasts and is starting to slow down a little. To get the roaster up to sufficient temperature to roast the beans it needs to spend part of its time in a cardboard box so it is recycling hot air. I’m guessing it will make it to around 250 roasts before ceasing.

Given the relatively small batch size of the Imex, I’ve also been down the Heat Gun method (usually referred to as HG/DB for Heat Gun/Dog Bowl). I don’t have a dog and so have used an aluminium steamer and a saucepan to roast in very successfully. The problem? I keep burning out heat guns. My first two were $20 XU1’s from Bunnings, but each only lasted around 40 roasts. Third time ’round I really splashed out on a $40 Ozito and it lasted about 60 roasts before it ceased running on its ‘high’ setting. Heat Gun roasting is good and easy, and cheap, and you get instantaneous feedback and good control over the roast. The downsides are turnover of equipment (!) and a very ‘hands-on’ approach meaning you are involved in every second of the roast (that can, of course, be good; but it means there is no flexibility).

I’m looking for something that allows reasonable control, good results and longevity of the equipment. Many are opting for drum roasting in a gas barbeque. That’s a reasonable commitment in dollar and space terms for me. Cost for an RK Drum is probably over $500 (USD350 plus freight for the drum and motor) plus the cost of the barbeque. And there’s the issue of the space for an additional barbeque… Batch capacity of the RK Drum is 4 pounds which is around 1.8 kg; but batches of over 1 kg seem to create some unevenness in the roast.

As an alternative (ie. cheaper, easier to hide in the garage, good roast control and ease of use) is the SC/TO - Stir Crazy/Turbo Oven - which is a turbo convection oven on top of a Stir Crazy popcorn popper base. The problem? There aren’t any Stir Crazy distributors in Aus.

[To be continued]

There are so many variables behind a cup of coffee:

• Beans - type, age, how processed, storage at every stage
• Roast - roast method, profile (temperature ramp and time at different temps), degree of roast, length of rest period
• Grind - fineness, consistency, how long ago, tamp & distribution (where applicable)
• Brew method - plunger, vac pot, moka pot, espresso machine, filter/chemex, other drip, etc.
• Water - temperature, water hardness, water pressure (espresso machine)

To name a few

Some are controllable, some are not. Some are significant, others not so much if at all.

One thing that is controllable and qualitatively discernible is the rest period. That refers to the time since the roast that the beans are ‘consumed’. Most beans I use are used between 1 and 10 days after roasting. Rarely less than 1 day, and I try to avoid beans as they close in on two weeks old.

Different roast methods and different beans benefit from differing rest periods. Last week I roasted some Jaque beans in an Imex. On day 3 they were a bit ‘bright’, but on day 4 they’d changed and become rounder and more complex.

I usually leave beans for my espresso machine to rest for 3 days before grinding. For plunging I’m not normally so fussed - but these Jaque beans at 4 days were noticeably better than at 3 days. Perhaps I’ll pay more attention to rest days in future.

What’s the point in creating this blog? Well, as a place to record and trace some small parts of my journey in coffee.

I’ve been homeroasting for a little over two years now and in that time my willingness to drink instant and percolated coffee has diminished almost to zero.