Welcome to Roasting Experiences

by Michael de Renouard

Convection heatFlow of heat by air using ventilator on cyclone and maybe on exit on stack.

Heat conductionDirect contact (drum, beans)Vibration between atoms/molecules (heat exchange)

Radiation heatElectro magnetic radiation, infrared radiation (IR). The more heat the more the human eye can perceive it.

Some difficult words

Endothermic reaction Heating from the outside of beans

Maillard reaction is a browning reaction of Amino acids and reducing sugars, (lactose, glucose, fructose etc.) Not to compare with caramelization. Starts at around 150-160

degrees celsius.

Exothermic reactionChemical process that releases heat from with-in! from around 180 degrees.

Once carmelization of beans begins, it is very important that the coffee mass does not lose heat so the exotherm reaction stops, or the coffee will taste "baked" in the

cup.

Pyrolysisis a thermochemical dekomposition of organic material at high temperatures in the

absence of oxygen.Coffees roasted at temperatures below pyrolysis will taste baked. After roasting, if the coffee beans are not cooled quickly, heat from pyrolysis will bake, or even start

self-igniting the coffee.

Welcome to this lecture, Roasting Experiences. In this lecture, I’m going to tell you a little about how we roast the coffee at Solberg & Hansen and our experiences with a old Probat 120kg roaster

and the fairly new Smart Loring 35 kg roaster.

This lecture is based on observations visually, by taste, trial and error and a desire to succeed. It is not a Scientific lecture, we’re not scientists, we’re craftsmen who try to get the full potential out of the beans. As roasters we work with the coffees as they change in freshness and humidity during the seasons and the only thing that really matters is the taste in the cup. Our profiles are always up for evaluation.

We’re the second last link in the quality chain of coffee and we have a huge responsibility towards those who trust us making a great product, buying our coffee.

I used to work in the wine tradeimporting wine on pallets, handing bottles out of a box to those willing to buy. In the coffee trade, I’m part of the process, bringing my coffee skills to good use. I’m a craftsman, I’m creating something wonderful.I’m a demigod, I’m a creator, let there be good coffee.

Craftsmen need tools to perform and we decided to try out a Loring Smart Roaster that could eventually replace our old Probat UG 22. We got it delivered in connection with the NBC last year, held in Oslo. Estimed companys like Da Matteo and Terroir coffee spoke in high regard

about their new money maker.

As mentioned in New York Times Style Magazine by columnist Oliver Strand, Oslo is the place for light roast coffees, juicy, naked and elegant in the expression. To reach these characteristics, we need good coffee, good machinery and good routines and a strict policy to discard or demote even the most exclusive coffees if they are not not up to our standard, within a narrow tolerance.

As we don’t really know anything else other than what our taste buds tells us, we can only find the better roast and try to replicate that and do it consistently.

With the Probat as the reference, the Smart Roast blew our minds about a cleaner cup and we fell in love with it right away.

The lighter roasts we like are very well executed on our Smart roast. Both for filter and espresso.

The roasts are crisper, more forgiving and with a wider sweet spot. Go a little dark or light, the coffee is still drinkable.

The transparency is very convincing, on the roasted coffee from Smart.

Maybe the combustion from the flame from the gas-, oil-fired roaster is adding something slightly unpleasant, that will slowly diminish over time, but never disappear all the way. The coffees from the Smart roast appears more naked, fresher, and with a fuller sweetness. This taste is not necessarily for everybody, as some people might prefer something else as our taste palette make you comprehend and taste according to experience, sensitivity, physical state etc.

Because S&H roasts relatively fast with higher temps, promoting the brightness in the coffee and the lively fruit acids and we can perform a very effective cool down of beans on all our roasters, we get rid of a lot unpleasant bitterness and lingering burnt/ashy taste, something some people confuse with strength, body and quality, the quintessence of a good cup of coffee.