while roasting with wood may not be âsimple,â in a field with a larger than normal percentage of professional Luddit
Tending the
Firebox roasting with wood B Y m at t b o l i n d e r
I
t’s been 45 minutes, and I still have a strong hour to go. The pile of maple and ash doesn’t seem to have gotten any smaller. In fact,
it just seems to have expanded outward. It always surprises me how long it takes to move and stack a cord of wood a paltry 30 feet. I forgot my work gloves back at the shop, which has helped slow the process down further, but there have been only a couple of splinters, the rain has held off, and most of the sticks look relatively straight and knotfree. I’m also a little flush, with a few endorphins starting to kick in. I’m feeling pretty good. As Thoreau wrote in Walden, the beauty of firewood is that it warms you twice. continued on page 38
36
roast
Ma r c h | Ap r i l 2 0 13
37
Tending the Firebox | Roasting with Wood
(continued)
But while this wood will certainly warm me for a time, it isn’t
“But why roast with wood?” I’m frequently asked. It’s a question
adage that any roaster who uses wood for a heat
destined for a fireplace, or even a Jotul or Vermont Castings woodstove.
that’s a little more difficult to answer than it probably should be.
Instead, it will be torched off in the small firebox of a Petroncini
(And, truth be told, it’s a question I ask myself every once in a while—
roaster. Soon, I’ll have enough fuel stored in my roastery to turn
especially if the wood I’ve ordered is late to arrive, or the rain doesn’t
process. While there have been significant
30,000 pounds of green coffee brown.
hold off when I’m stacking it, or if I don’t particularly feel like splitting
advancements in roasting technology over the
C&C Co. Ltd. in Takasaki City, Japan, uses a Fuji Royal wood-fired roaster. | photo by Mark Shimahara
38
roast
source quickly learns to ignore or forget. And yet roasting is, ultimately, a simple
my delivery into various sizes on a given
years—thankfully, our roasteries don’t resemble
morning.) If I’m not in a chatty mood, I might
“labor in the lower range of Dante’s Inferno
just ask a customer what they think about
amidst smoke, stress and burned beans,” as
the pour-over in their hand or the espresso
Mark Pendergrast describes the earliest wood
on their tongue. “It’s great!” is an answer in
oven-based commercial operations in his book
itself. I know I can get good results with my
Uncommon Grounds—it’s still just the controlled
roaster—the only commercial roaster I’ve ever
application of heat to a bunch of seeds. And
operated—and that answer is good enough for
the drum roasters being used by many roasters
me. The longer response has to do with things
today do not look or operate very differently from
like market differentiation, or the fact that I’ve
those used in production 150 years ago. Indeed,
run woodstoves at various residences my entire
many of us prefer old machinery. Quality drum
life and feel comfortable with wood burning,
roasters with a century of service on them are
or that on an aesthetic level I actually get a kick
not liabilities, but precious commodities. So
out of handling and splitting cord wood. And,
while roasting with wood may not be “simple,”
if I’m honest, there’s probably a masochistic
in a field with a larger than normal percentage
tendency to make some things in my life more
of professional Luddites, preferring pour-over to push-button drip
roast with wood—tradition itself was always mentioned, and usually
difficult than they need to be: “Simplify,
and manual paddles to super automatics, roasting with wood in the
near the top of the list.
simplify, simplify” is a different Thoreauvian
21st century is not as anachronistic as it might seem.
The wood-fired roaster at C&C, Takasaki City, Japan. | photo by Mark Shimahara
When I asked fellow wood roasters the same question—why they
continued on page 40
Ma r c h | Ap r i l 2 0 13
39
Tending the Firebox | Roasting with Wood
(continued)
Joe Mancuso, general manager of Seattle’s Caffe D’arte—a roasting company whose founder is from Italy, and a company that uses a mixed fleet of gas and wood-fired roasters—says that
experiments they found that cedar in particular produced a roast that
it does is because of its “neutral” smoke character. Hausbrandt of
was “terrible.”
Antica also says that the beech wood purposefully chosen for their
But the consensus of the roasters I spoke with was that they
operation is a clean and complete burning fuel with little resin in it,
roasting with their 1949 Balestra “brings them back to their
were not attempting to add smoke flavor. In fact, DiRuocco of Mr.
producing minimal smoke and ash. Likewise, Bruce Karnes, owner
artisan roots.” Alessandro Hausbrandt of Antica Espresso in
Espresso notes that one of the reasons his business chooses the wood
of Summermoon Woodfired Coffee in Austin, Texas, says that while
Trieste, Italy, alludes to the use of wood as being not so much
he’s “thoughtful” about the mesquite and live
a choice but a simple historical fact, given his company’s
oak he uses, and refers to a “synergy” between
century-plus tradition of wood roasting. John DiRuocco, vice
wood and cup outcome, that ultimately “it’s
president of Oakland’s Mr. Espresso, another company with an
about the coffee,” rather than the wood.
Italian connection and decades of expertise, also alludes to the
It’s worth noting that the choice of clean-
attraction of wood roasting as a way of “maintaining the skill
burning wood also goes a long way to ensuring
and craftsmanship of coffee roasting.” To be sure, most of these
that the emissions from wood-fired roasters are
outfits have availed themselves of modern technologies, from
not nearly as heavy as one might expect. Wet
multiple thermocouples and computer logging, to aftermarket
wood is the primary contributor to creosote
modifications that allow for such things as variable airflow and
and soot, but the carefully selected and well-
drum speed. But the bottom line is that with a wood roaster, an
seasoned fuel used by most roasters burns hot
individual puts fuel to flame and monitors the progress of each
and produces little ash. Further, the amount
batch. As Tim Curry, owner of Wood-Fire Roasted Coffee in Reno,
of wood needed to roast coffee is relatively
Nev., explains it, “it’s more of an artisan process—you can never
small. Consider that even a little woodstove
walk away from the roaster.”
is expected to heat hundreds of square feet,
But tradition doesn’t pay the bills. Only coffee drinkers can
while a coffee roaster is designed to focus all
do that, and so the bottom line for wood roasters is that they, and their customers, like what results in the cup.
Smoke? Nope.
of the energy from a firebox into a very small At Antica Espresso, coffee is roasted with wood on a custom-designed, 120-kilo Petroncini. photo courtesy of Antica Espresso
and tight space. (My 30-kilo drum is about the continued on page 42
What is that result? It varies from company to company, but perhaps the biggest misconception of wood-roasted coffee is that the finished product is actually smoky. While the beans do in fact come into contact with wood smoke from the firebox during the entirety of the roast, as I tell my own customers, roasting coffee with wood has very little in common with letting a pork shoulder bathe in smoke overnight at low heat. Coffee roasting is a process timed in seconds, not hours. And so, while contact time with smoke certainly has some influence on how the coffee tastes, most roasters suggest that the wood-fired process adds a bit of nuance and subtle intrigue. The object for most companies is to unlock what’s in the bean, rather than to do something to it. Can smoke actually change the outcome of the roast? The answer is a qualified yes. Curry notes that it’s possible to get a smokier profile with extremely dark roasts, as any oil that emerges while the bean is still in the drum will readily absorb smoke with which it comes into contact. There are also companies that purposefully use aromatic woods for the effect they have on their coffee. Timothy Gikas of The Mesquite Roasted Company, based in Big Lake, Texas, outlines a process that involves roasting outside over a wood fire, in which 20-pound batches are hand-turned in a perforated stainless steel drum that sits above mesquite coals. But even in this case, the result is not a “smoked” coffee as much as it is a final flavor profile to which the chosen fuel source contributes in some way; Gikas calls the resulting characteristic “earthy.” On the other hand, Gikas also mentions the very real and powerful effect wood smoke can have on an outcome, noting that in their
40
roast
Ma r c h | Ap r i l 2 0 13
41
Tending the Firebox | Roasting with Wood
(continued)
size of a galvanized garbage barrel.) Of course, the roasters I spoke with
and that he is obligated and willing to meet the tight pollution and
who were operating in metropolitan areas were using afterburners
emissions standards of his city, but lamented—as many roasters
note that they draw out their profiles and roast times in order to create what
and abatement equipment, but they explained that this was for the
do—the expense (and the ironic carbon footprint) of the gas necessary
they believe to be a less angular and fuller bodied espresso. DiRuocco says the
emissions generated from the roasted coffee, and not the wood itself.
to power it.
difference in roast times between his company’s coffees meant for brewing
Hausbrandt notes that his own roasting plant employs an afterburner
Roundness in the Cup If there is a particular quality that wood heat seems to provide—or, at least, a quality that the various companies I spoke with used to describe their own coffees—it would be in the overall “roundness” of the cup. The roasters I spoke with used terms like “depth,” “balance” and “smooth character.” Hausbrandt likens the “impact” of roasting with wood to what takes place when a pizza is baked in a wood-fired oven or when beef is cooked on a charcoal grill. The difference is not so much in the addition of flavor, but in a resultant texture and completeness. As Karnes says, “When someone spends 25 bucks on a rib-eye, they’re not going to put it in a frying pan over an electric element.” It may be difficult to break down into discrete characteristics, but roasters using wood
Stoking the flames with fresh beech wood at Antica Espresso. | photo courtesy of Antica Espresso
Some roasters—especially those following in the Italian espresso tradition—
and designed for espresso can be up to 10 minutes, with the longer roast times “smoothing” out acidity while increasing sweetness and enhancing body. DiRuocco attributes this in part to a longer drying phase, as the natural moisture content of wood necessarily slows down the initial stages of the roast. Hausbrandt also notes that the fuel source itself seems naturally to lead to longer roast times, though those used by Antica are not markedly longer than those you might find utilized with gas-fired drum roasters, and that their coffees are dropped before the onset of second crack in order to preserve inherent bean characteristics. My own experience tells me that wood does take a little longer than those times used by my gas- and propane-fueled peers, and that while I can knock a minute or so off if I work at it, the wood just “wants” to go through my profile points a little more lazily. Whether this “roundness” and muted acidity is due to the wood itself or simply the product of drawn-out profiles is probably debatable. But Mancuso notes that the coffees dropped from his 63-year-old Balestra have more body and viscosity than those that come from Caffe D’arte’s small army of gas-fired roasters. And while these differences can in part be attributed to D’Arte’s using roast profiles customized for wood, he has experimented enough to know that the primary difference is the roaster, and heat source, itself. The same green roasted
know the overall effect is noteworthy.
continued on page 44
Antica Espresso has been roasting with wood for more than a century, starting with this old-school roaster. | photo courtesy of Antica Espresso
Daily news from throughout the web for coffee professionals.
www.dailycoffeenews.com
42
roast
Ma r c h | Ap r i l 2 0 13
43
Tending the Firebox | Roasting with Wood with identical profiles in wood- and gas-
no direct contact between flame and drum
The fact that experience carries
fired roasters has resulted in non-identical
wall—the bottom of the drum is insulated
such weight in wood roasting also poses
coffees.
with brick—and so the drum heat is even. It
certain challenges. Curry is still the only
takes a while for it to get up to temperature,
roaster in his operation, which means
roaster who’d identify himself as Third
as the brick mass acts as a heat sink for the
that he “hasn’t had a real vacation
Wave were the term not dated and a little
first half hour after I take a match to my
in years.” Mr. Espresso and D’arte,
obnoxious, I enjoy and am able to produce
kindling, but once it gets up to roasting
however, employ multiple roasters with
bright coffees that have plenty of snap.
temperature, it’s pretty stable.
decades of experience in the industry, all
On the other hand, as a contemporary
While I, too, like to think that the coffees
blessing and a little bit of a curse. On the
with wood. (At D’arte, a new guy on
the high-grown Centrals and East Africans
one hand, the persnickety nature of our heat
the block entering his ninth year was
that I put through the paces do not want for
source means that bringing an element of
just now being allowed to work with
acidity and liveliness.
predictability to the process is a good thing.
their wood roaster, Mancuso said with a
We cannot set gas jets to full at one moment,
laugh.)
How does roasting with wood work, and specifically, how is the application of heat controlled? There is no single technique. It depends upon the machine being used, and in this respect is no different from gas or propane drum roasters. Each machine has its own quirks and needs. Curry’s roaster, a 15-kilo Balestra, has direct contact between flame and drum wall, along with a blower that pulls hot air from the firebox through the drum and bean mass itself. He hits his profile targets by way of a combination of stoking the fire at various points and adjusting baffles and dampers. On the other hand, the batch sizes in the 240-kilo production machine used at Mr. Espresso cannot be quickly influenced by the addition of wood to the fire, and so DiRuocco notes that fuel, if it is added at all during a roast, is added only at the beginning stages. Instead, DiRuocco depends upon airflow and drum speed, as well as a damper that adds or restricts oxygen to the fire. And Summermoon’s roasting works—a custom-made brick oven with 8-foot-long steel tubes that are turned via large implement wheels and pedal power from an attached recumbent bicycle—is unique unto itself, operating by conductive heat from the brick and steel and convection from the draw of an actual chimney. Karnes likens figuring out how to best use his roaster after its design and installation to “building a giant violin and then learning how to play it.” My own experience is with a 30-kilo Petroncini with high airflow that roasts convectively and conductively. There is
roast
of whom are comfortable with roasting
Stability for the wood roaster is a
my roaster produces have a “round” quality,
The Wood-Roasting Process
44
(continued)
Sourcing wood can also be tricky.
and then cut back to quarter power the next. And no wood fire is ever exactly the same.
Mancuso calls finding the right wood
Not only do different sized pieces of wood
his “gray hair maker”—not too wet, not
burn differently, but different types and sizes
too dry, not too many knots. But other
of wood can dramatically affect the amount
roasters seem to have relationships with
and rate of heat that a fire throws. I like to
wood suppliers as a cabinet maker or
have a few different types of wood in varying
luthier might. Curry has been sourcing
sizes on hand. I’m particularly fond of white
his oak from the same supplier for a
ash, because of its ability to take off quickly.
decade, and DiRuocco treats his own
(It’s also fun to split.) I’ve also learned to
wood supply in an even more specialized
avoid certain types of wood, like red oak, that
way, using only blue oak from a
retain high moisture levels.
particular kind of sloped terrain that
What actually happens in the firebox
results in a moisture content a little
mirrors what happens to the beans in the
lower than your typical green might
drum. When wood is added to flame, for
have. I started by using wood that I cut
a very brief time the mass of combustible
and split myself, but have ended up
material is endothermic, but once a turning
buying local kiln-dried wood by species
point is reached, it begins to increase
and by the cord, for consistency’s sake.
temperature, and a roaster has to anticipate
Despite the challenges, roasters
how much heat and its rate of increase will
using wood are enthusiastic about their
result. As any roaster knows, large batch
chosen technique and wouldn’t have it
sizes of green can get away from you if you’re
any other way. If you’re going to work
not careful, and the same goes for wood fires. More importantly, too large a fire can mean difficulty in slowing down or halting
Tim Curry, owner of Wood-Fire Roasted Coffee Company in Reno, Nev., uses oak to fuel his 15-kilo Balestra. | photos courtesy of Digiman Studio
next to a wood fire for hours on end in Texas in August, Karnes jokes, you really have to love what you do. And enjoy a challenge. “It helps to be as stubborn
the overall rise in temperature needed for roast development. I’ve found that it’s best to
significant challenge, but one that he seems
as I am,” Curry laughs, “but I’m happy
use gentle curves that work with the wood,
to relish. The folks at Antica also mentioned
I’ve chosen this path.” I always smile a
instead of trying to fight it.
similar issues, but noted that modern
little when I read Christopher Schooley’s
Agtron equipment, along with the fact that
Firestarters interviews. A fire in my
seems to be batch consistency. Mancuso
the company has an institutional roasting
roastery does not mean something
notes that it’s “not easy to control all
memory of generations—Hausbrandt’s great
has gone horribly wrong, but just as
the variables—flame, wood, barometric
grandfather started roasting in Trieste at the
planned.
pressure, whether it’s the first or ninth
end of the 20th century—assists in achieving
batch” (and the resultant change in heat
as consistent a result as possible from
transfer), and that it takes a specific skill set
their 120-kilo custom-designed Petroncini.
to do so. Curry states flatly that wood roasters
And Karnes says that his roaster produces
roaster at Matt’s Wood Roasted Organic Coffee
are “dealing with an inconsistent heat
consistent roasts after its oven has been
in Pownal, Maine. In 2012 he opened the Speckled
source” while at the same time “trying to
brought up to temperature over the course of
Ax coffeehouse in Portland, Maine. E-mail him at
achieve a consistent product,” making for a
two hours.
[email protected].
The biggest challenge across the board
Matt Bolinder is the owner and
Ma r c h | Ap r i l 2 0 13
45
