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.

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.

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

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

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***

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

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

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

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

Lots of great items for homeroasters and more!!!
Throughout the month of May 2009, Homeroasters.org 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 Homeroasters.org and enjoy the auction.
Kick It Up for Coffee Kids Auction Homeroasters.org link
cheers,
farmroast

"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

Hand Coffee Mills-Coffee Grinders-Manual for Brewed and Espresso

To brew great coffee or espresso the quality of the grind is extremely important. The grind must be even with just the right amount of fines for espresso for the proper bind of the puck. Too many fines will produce a bitterness to the cup along with sediment. The rest of the grind particles need to be consistent with good surface area.

Coffee is best ground rather than chopped/diced. The whirly blade grinders are not really coffee grinders in the traditional sense because they chop/dice the beans and produce a poor result. Coffee grinders use hardened steel burrs either flat or conical for grinding. The quality of the grind will depend on the the quality of the grinder. Electric grinders can be bought for $50.- $2000+. More money will get you a better grind and better durability. The quality of the grinder is most important when producing espresso. A decent home espresso grinder is $200+. Many will buy a used commercial grinder such as the Mazzer mini or super jolly for $200-$400 as they are built for years of trouble free grinding. The problem with these commercial grinders is they are quite large and heavy and expensive.
So what if you want a quality grind from a durable and smaller grinder for less than $100. Consider A Hand Coffee Mill! A good quality hand mill can produce a grind on par with top commercial grinders. They can be adjusted for fineness of grind. The best co. still producing these mills is Zassenhaus and can be found on the Sweet Marias coffee site. I find the old grinders by Zassenhaus, Dienes and KYM are the most beautiful in design and the highest quality build. You just have to find one in good condition that spent more time on display than it did grinding coffee! New no-name replica box hand mills have poor quality burr sets and should be avoided.
There is a family owned site that refurbishes old mills and offers them for sale. They do great work. www.orphanespresso.com

A forum thread with lots of pictures and info on hand mills.
Shown are a few pictures from my collection of old coffee mill. between the 1920s and 1950s.
Hand Mill disassembled Wall mounted model

Buying Green Coffee Beans

There are an increasing amount of vendors of green beans for home-roasters. "Information" is what I look for.
Freshness- Do they list the crop year or do they say that all of their beans are recent crop unless identified as aged. Do they state when they received the beans, because this will help you know how long you might be able to continue to store some at home. Do they tell you anything about how they store their beans?
Bean Details- I need more than the word "Colombian". Farm or Cooperative name, region, elevation, soil type, varietal, how processed, bean size or mixed sizes, chemical usage and amount of defect beans are all very useful bits of information.
Cupping Notes- Every coffee is unique and cupping notes can describe the individual characteristics of each coffee.
As stated by the SCAA (Specialty Coffee Assoc. of America):

"Cupping is a method of systematically evaluating the aroma and taste of coffee beans. It is often used by growers, buyers and roasters to assess the quality of a particular coffee sample. Proper cupping requires the adherence to an exacting set of brewing standards and a formal step-by-step evaluation process. A trained cupper generally looks at six characteristics:

• Fragrance - the smell of beans after grinding
• Aroma - the smell of ground-up beans after being steeped in water
• Taste - the flavor of the coffee
• Nose - the vapors released by the coffee in the mouth
• Aftertaste - the vapors and flavors that remain after swallowing
• Body - the feel of the coffee in the mouth"

Some local roasters will sell you green beans and should be willing to answer questions. Email on-line vendors if needed information is not on their site.
www.sweetmarias.com(see "links") is an example of a *great* green coffee bean online vendor! Detailed information, quality and integrity.

Updated: DreamRoast - Home Coffee Roasting Roaster

A few updates, Added a custom rim for the Turbo Oven top to sit in using bands of aluminum and a ring of high temp. food safe silicone tubing for a gasket. The convection top is a stock Galloping Gourmet Turbo Oven. The heating element and the convection fan have been wired directly to the toggle switches marked "F" and "H" on the front of the turbo oven top. The heater line goes down through my controls and variac. The left thermocouple reads bean temp. and the right measures air temp. as it hits the beans. The bean bats in the roasting pot are variable speed from 0-240 rpm. I cut the roasting pot down to 4"deep. I can easily roast between 1/2lb and 3lbs with an almost infinite amount of possible roast profiles. The whole roaster tip dumps into the cooling drawer that cools with a fan pulling air through the beans. Most of the chaff ends up in the chaff canister.

DreamRoast Coffee Roaster

roaster
A) Variable speed convection fan 0-5600rpm
B) High/Low range convection fan toggle
C) Main heater On/Off toggle
D) Beanbats speed control
E) Chaff canister
F) Roasting pot
G) Boost heater control
H) Main heater and fan
I) Tilt dump
J) Bean temp. thermocouple
K) Air temp.
L) Volt/Watt digital display "Kill A Watt" meter
M) Variac 0-140v for main heater
N) Timer
O) PID
P) Cooling drawer- removable cooling tray
Q) Base with Beanbat speed control gearhead motor 0-330rpm
R) Dumping handle in back

First Look-1930s Reneka Type 50 espresso/coffee machine rebuild

Yes this thing makes coffee. Built in the 1930s in France. It's about 48"x 24" in size and is made to be wall mounted. One of the first commercial automatic coffee machines! I will be rebuilding this creature over the winter. More posts to come.

"Fresh" Roasted Coffee Beans

"Fresh brewed coffee" is a commonly used and understood term. We have all experienced the results of a pot of brewed coffee that has been on the warmer too long. But what about "fresh" roasted coffee. As with all natural foods, roasted coffee beans spoil with time. It is the spoiling of the oils in the beans that most effect the flavor of the brew. The oils with time and exposure to oxygen become rancid. Before coffee beans are roasted(known as green coffee beans) the oils in the beans are naturally protected(won't get into the science of it in this post) for up to a year with proper storage. But once roasted the oils become extremely vulnerable to deterioration. The fresh flavors only last for about 10 to 20 days!!! After that the stale tastes begin to show up. Think of the difference in the taste of "fresh milk" compared to what it tastes like just as it turns a little sour a couple days after the "use by" date. It is the most protected secret in the coffee industry. Yes!!! that means you have been drinking stale/rancid coffee for years and probably weren't even aware of it. You have probably never experienced the sweet and incredible flavors in fresh coffee. The good thing is you now know better. And yes you can buy "fresh" roasted coffee or even learn to roast your own as many homeroasters now do. Some local roasters or coffee shops will sell you fresh roasted beans and will indicate the date roasted(if they can't tell you the roast date don't buy them. Or there are a number of online roasters that can have fresh beans on your doorstep within 3 days of roasting giving you a couple weeks to truly enjoy. Always grind just before brewing(ground coffee becomes stale much faster). And store your beans in a airtight container or in a one way valve coffee bag in a cool dry place. The fridge or freezer is not recommended(future post). Warning! once you've experienced fresh roasted coffee you will not want to drink anything but.

"DreamRoast" New Homebuilt Coffee Roaster for Roasting Beans

This is my newest 1kg electric coffee roaster.
Click on the title of this post to link to more pics and descriptions

Jacu

Jacu coffee
Please don't ask me to explain more.

Colombian Micro-Lot Super Vacuumed Packed Green Coffee For Roasting

This superb Colombian was super vacuum packed in country in 5 kg wafers. Due to recent port delays with warm and humid conditions a few of the best coffee buyers in the US started having their micro-lots shipped this way to ensure freshness and quality. This lot was grown by Reynel Perez -Finca La Circasia Farm, Planadas, Tolima Colombia. The Farm elevation is about 5,500 ft. in the south central part of Colombia. This coffee lot of less than 1000 lbs was recently purchased by Paradise Roasters of MN and scored 96points!!!! in a recent Coffeereview.com cupping.
Click on the title of this post to read the full review of this exceptional coffee.

Coffee Bean Pictorial Roaster Roasting

1 Dried whole cherry
2 Bean with hull-parchment
3 Hull-parchment
4 De-hulled green bean with
silver skin
5 Polished green bean
6 Roasted Bean