Saturday, January 21, 2012

Bean Temp. Rate of Rise **BT RoR** an approach to roasting and analysis

I've been interested in BT RoR for several years. First, to consider a different way to drive a roast and second, having something more detailed for post roast analysis.
Through the efforts of the amateur/home roaster community, various types of monitoring and also controlling systems have been developed over the past couple years. (see posts below for more info.)

As amateur home roasters we tend to play with small amounts of various lots of different beans. Our stash is not a "production" stash. It's collection of a couple/few lbs of various great coffees. We can't mess around with several roasts of a bean trying to nail the preferred roast profile. But instead buy known great lots and learn as much as we can about them before we roast.  Then create a profile and try to nail it the first time. If we spend big bucks on a couple batches worth of a Gesha coffee to roast, the pressure is on. Beans I get from Sweet Marias have Tom's very detailed descriptions and info. Pretty much all a roaster needs to know about a lot to develop a good approach to the roast.

Having an approach and driving dead center with how the beans are actually reacting on the first roast is the next trick. This is where the addition of live BT RoR readings are useful. The trend of the bean temp rate of rise allows a quicker heads up that changes need to be made(factoring in ET/MET,Time). RoR allows easy calculations of upcoming arrival times for key points during the roast. The focus needs to be on the senses sight, smell and sounds.  With quick glances at BT RoR needed changes can be considered and made faster to be keep that focus on sensory monitoring. If the beans are telling you they could stand more heat transfer and your looking for speed in that segment for hoped cup results, than the quicker you can realize that and make adjustments the better.
green line is BT RoR (vertical readings without the 0 = degrees rise f/min.)
Red-BT f
Yellow-ET f
Tan -Voltage to electric element (juice)
The list on right are most recent readings per 5 sec.
.csv file per sec. of readings saved

BT RoR graphing substantially adds detail to post roast analysis. It is basically what I try to gather together in my mind by looking at a typical time/temp ET and BT graph. Instead the BT RoR line becomes the focus graph showing how the beans reacted to the other conditions shown. It's what completes this different approach to roasting. It's been an enlightening experience that does take some time to get used to.  Adding  BT RoR can also really help when wanting to communicate a roast profile and to transfer profiles between 2 different roasters.

 BT RoR readings have been used in various ways in the recent past. It's when combined with the graphing ability that a complete approach shift can be considered. ET RoC monitoring ET rate of change may be useful for high heat mass roasters with a proper TC placement.

If the 1st. World Roasting Championship could add BT RoR graphing of the roasts it sure would make it more interesting in analysis.

Monday, May 30, 2011

New monitoring system for my homebuilt coffee roaster

This system was designed by a group effort of Homeroasters. It uses a customized Arduino and a custom "Juice box"(to measure voltage off the variac).  It monitors Time, ET(environmental temperature in the roaster), BT(surface bean temperature), RoR(rate of BT rise/min.) and Juice(voltage from the variac to the main heating element). It uses the custom designed pGesha software program. Here is a link to the hardware and software, tc4
I can hook up to a computer through USB or view on the LCD display.
I'm about to mount the monitoring hardware in a project box.
This was a roast of Ethiopian with an extended
finish for espresso.

Saturday, May 07, 2011

George Howell, Terroir Coffee: "How to" Videos

George Howell  has put together some new informative videos. George is a leading authority in specialty coffee.
Coffee bean fundamentals
Coffee brewing principles
Coffee freshness and storage
Drip coffee brewing
Manual coffee brewing
George's "How To" videos

Sunday, March 06, 2011

Home Coffee Roasting Competition: Judging Videos

A fun event! My entry was in the Single Origin category. Tom Owen Judge
The top video is the single origin roasts
The below video is the blends

Saturday, September 25, 2010

DreamRoast, Driving with Bean Temp. RoR

The Dreamroast now has a bean temp. RoR(rate of rise) meter. The datalogger in the back left displays the ET (environmental temp.)in the roasting pot. And the BT (bean temp.). The DMM displays the rate of rise of the bean temp/min. A Homeroaster made the circuit board to connect between the thermocouple and the DMM.
The live numerical RoR works really well with manual control roasting.
***A new control system is arriving soon***

Wednesday, May 12, 2010

Books: Scott Rao books on Espresso and Coffee Brewing

Scott Rao has many years of experience in the world of coffee. He has in the recent past written 2 books, the first being "
The Professional Barista's Handbook" about espresso and his newest, "Everything But Espresso" about brewing techniques.
These books are well written and helpful for professionals as well as anyone who wants to better understand the art, science and best techniques for coffee preparation.
Scott Rao's Books

Sunday, September 27, 2009

Darker vs. Lighter Roasted Coffee

There a several differences between a darker roast and a lighter one. I divide the taste in the cup into the flavors in the coffee and the roast flavor(similar to the char taste of BBQ or broiling, producing carbonic acid). The darker the roast the more "roast" flavor will be in the cup. There are also various flavors in the coffee that will be stronger or more subdued depending on the degree of roast. Coffees that have fruited
(berry, stone fruit, apple, lemon, ginger and or nutty flavors (depending on the origin and varietal and type to processing)will shine at a lighter roast while chocolates will stand out more at medium to slightly darker levels. Vienna and French roast levels will be dominated by "roast" tastes. The quality of the coffee beans is much more important in light roasts. The growing conditions, care in picking and sorting, insect damage, molds, care in processing, handling, shipping, storage etc. will all effect the final quality. These are called defects in green coffee beans. Many beans are only dark roasted to cover up the defects in the beans. Light roasting quality beans takes much skill but when done properly yields a fantastic cup. I highly recommend trying lighter roasts from a quality Roaster.
check out this related post: "Fresh" Roasted Coffee Beans

Monday, May 25, 2009

Sweet Maria's launch a New Web Home Coffee Roasting Forum

Sweet Maria's, The best dedicated online vendor of green coffee beans for homeroasters has just launched a new web forum site. Tom and Maria Owens have one of the finest online businesses on the web. They provide a wealth of information for the homeroaster including other coffee related resources. Tom travels the world to find the finest farm grown coffees. Many of the coffees are bought directly from the farmer or cooperative who are paid well for them (farm gate™ direct trade). The coffees are often specially packaged at source to maintain quality and freshness. Tom provides detailed descriptions and cupping notes on all the beans offered. New Forum
Sweet Maria's also offers a weblog, a Roasted weblog, a email discussion list, and a Coffee image gallery

Thursday, April 30, 2009

"Kick It Up for Coffee Kids" Benefit Auction, during May at

Lots of great items for homeroasters and more!!!
Throughout the month of May 2009, is conducting
auctions on a wide variety of items, many of which the specialty
coffee industry donated with jubilation. Items up for bid range from
assortments of top-quality green coffee, to magazine subscriptions,
grinders, brewers, roasters and much, much more; all proceeds going
directly to Coffee Kids.

Coffee Kids® Grounds for Hope was born out of the specialty coffee
industry by Bill Fishbein in 1988. Coffee Kids® has distributed over
$4 million dollars in funds “to help coffee-farming families improve
the quality of their lives.” With four distinct areas of focus, Latin
American countries have realized improvements in healthcare, education
for children, community-based projects and micro-credit loans that have
enabled over 4,000 women to own their own businesses and support their families.

If you would like to bid on an item, please register as a member of and enjoy the auction.
Kick It Up for Coffee Kids Auction link

Friday, April 24, 2009

"Terroir Coffee" say's it all

George Howell of Terroir Coffee Co. introduced me to the word "Terroir" a few years ago. A word I wish had it's equivalent in English. It's a term not simply explained or understood. In fact it may take a lifetime journey. For coffee it's the "all" that's in your cup. The rains, winds, sun, soil life, stewardship, processing, handling, transport care, storage, roasting just being a few. How important is "Terroir" in our coffee and in all our foods and fiber we consume? It is the most important concept we need to understand. Terroir coffee does not just quench our thirst or perk our day. Terroir coffee fulfills all. Here's a link to George Howell's Terroir story. Story