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Tuesday, 27 August 2013

Coffee Roasting Notes on Turning Point in a roast

Examining our own preconceived ideas on roasting?

We at Quaffee are forever testing our own roasting knowledge boundaries, we love roasting coffee and love looking at ways to improve and or understand how we can improve our roasts. With the change in temperature and weather recently we have been looking at charge and turn around temperature of a each of our roasts.

The charge temperature (or starting temperature) is the temperature you want the air in the roaster to be when you drop the coffee into the roaster (at that point the coffee is at room temperature). At the point that the coffee is introduced to the roaster the air temperature in the roaster drops and equalizes with the temperature of the beans. When it has equalized the temperature again starts increasing. This point this happens is called the delta point or turning point of the roast.

And so the games begin

So we started play with these turning and charging temperatures trying to see what the results were. What we found was that it affected the way you kick started and controlled the roast from there, but we were looking for a point at which the coffee may change in taste.

So off we went to do some research to see what others had found and discovered that there has been quite a lot of debate regarding this issue however there are also some commonalities:
  • Charge and turning point are roaster specific
  • Flame level at drop is coffee and roaster specific
That said there seems to be an agreement that most important consideration is what happens after chemical change starts. This is when the beans change from green to yellow and then onto brown. roasting profiles linked at yellow browning
Roasting Profiles linked at Yellow Browing


What tends to be the agreement is that if you roasted the coffee so that the roast profile from the yellowing stage is more or less the same, than no matter what the charge temperature is and the turnaround temperature is it is difficult to distinguish the difference when the coffee is tasted afterwards. A sample of the graph showing these differences is above.

The forum post that I found worthwhile is:

You can a summary of this discussion on youtube, where we got the original image:

Thursday, 15 August 2013

Traditional Coffee Roasting in Indonesia

The Dutch bought coffee to the Indonesian islands. At one stage it was very sought after, especially the coffees shipped from Java. A lot of the best coffees where destroyed in the coffee rust epidemic in the late 1800's and now 70 percent of Indonesian coffee is Robusta. There are still a collection of Arabica farms, and the most popular Quaffee has sold is the Mandheling. My sister was recently travelling there and was lucky enough to see some traditional open pan coffee roasting. She sent us the pictures and thought perhaps this would be interesting. The coffee is roasted and "ground" the way it was traditional done, and is still done in many places in the world, especially the cradle of coffee Ethiopia.

Open Pan Roasting

Here a lady is roasting here is using a fire and open pan. These to pictures show you her roasting on the open pan, then increasing the heat by blowing on the fire.
Roasting in an open Pan
increasing heat to the roast
Adding heat to the roast

"Grinding" / Preparing the grinds

Once the coffee is roasted it has to be "ground" this is the method that has been used for hundreds of years. A standard method of crushing the beans so that when added to liquid it can expose the coffee.
Indonsian grinder
A traditional "grinder"

Thursday, 1 August 2013

Quaffee Newsletter Vol 2 Issue 5 - Aug 2013


A year of roasting out of Buitenverwachting is behind us. This newsletter is mainly about landed and anticipated coffees.

Coffee News

In the last 6 weeks we have been assessing a number of new harvests, and some other offerings we have had.


We finally got our Yirgacheffe, which we ordered November last year through Kiama. Kiama found us the Kenyan coffees we do, which we are happy with. The Yirgacheffe comes from a processing plant in the Yirgacheffe town of Ethiopia. Even though it costs us a little more than the previous Yirgacheffe, which we got from a bulk importer, we have kept our price the same.

Most Ethiopian coffees are actually sourced through the Ethiopian Coffee Exchange and there have been rumours for a while that are they are watering down the classic coffees like Limu and Yirgacheffe with other coffees. We have suspected that the Yirgacheffe was not quite Lemony enough for a few years and hence where excited to get involved with Kiama in sourcing Yirgacheffe from Yirgacheffe. You can read more about Yirgacheffe here:

Coffees on the Sea

We have also secured three additional coffees from Café Imports, who are American based agents that work direct with the coffee farms buying lots that they like. We have learnt from experience that we can get great coffees from agents like these and they end up being a reasonable price. When we have gone direct to the farms the transport cost has represented up to 40% of the coffee landed price. So some of the farmers are now referring us to these types of agents.

The coffees we have on the water that we liked of these are:

Guatemalan Huehuetenango

This is a coffee from about 350 small-holding farmers, that are part of the Highland Coffee Presidium Slow Food consortium. The coffee is balanced, juicy and tangy with chocolate, cranberry and lime. The Limited Edition Cup of Excellence winner we are selling, is from the same Huehuetenango region of Guatemala. We selected this coffee from 4 other Guatemalans we tasted.
PulpNatural Process
Pulp natural process

Brazilian Pulped Natural Yellow Bourbon

We must admit that we have been bursting to do a Yellow Bourbon. The Bourbon varietal is named after the Bourbon Island, where the horticulturists developed it by letting an Arabica typica plant pollinate itself. This varietal of Arabica is very popular in South America, and it has a two sub species that produce a yellow and orange cherry when ripe rather that the classic red cherry. We first heard about these varietals in 2008, and have not been able to source any yet. When we got our samples from Café Imports (which we taste blind, not knowing their origin at all), the Yellow Bourbon stood out without us even knowing that, that was what we were tasting. The pulped natural process means that the coffee is dried on the cherry and then either de-pulped manually or semi automatically using a depulper. The result is when it is done properly there is a distinct body to the coffee, and strong fruit. In this case the coffee is citric and heavy with fruit tones.

Mexican El Triunfo Biosphere Reserve

As much as we believe there is a place for the Fairtrade and organic movement, we try purchase as many coffees in a way that the farmer benefits most. We want to be the change we would like all to adopt. It is for this reason that our packaging is fully recyclable and locally made.

Last year we imported 2 Mexican coffees and they were very popular. This year after tasting a few we selected the one from the El Triunfo Biosphere reserve, not knowing that this coffee is a Fairtrade and organic certified coffee, so that is a bonus. The coffee is rich, with caramel, raisin and sage, and we loved it.

More coffee things

If you are a regular visitor to, you will see a few new coffees, and some are gone. Some have sold out, but we have also removed 2 regulars Excelso and Sul da Minas. We have remvoed these two since we have decided the quality of these products is unpredictable and since we only sell what we can drink we have removed these coffees. We have added and good El Salvador (which we are receiving positive feedback) and the Nicaraguan Tesoro is doing well too.

We participated in the Mexican Cup of Excellence auction partnering with an Australian and South American company trying to win lot 15. The cost of the auction is USD1 per pound, and then the actually price of the coffee is what the farmer gets. We will only get this coffee near the end of the year, and will release it under our limited edition range. Once we know all the costs on this coffee, we will be posting all of the costs on our blog, and will welcome any comments on how much people believe we should sell it for.

Machine News

There are a number of new machines in the Jura range, you can view an updated summary here: There is also a special where the Baby Jura Ena1 is now coming free with its own standalone frother. Not a bad offer for those that drink no more than 5 cups a day at home.