eBlog Cafe: Amateur Home Coffee Roasting-Home Built Roasters

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

2012-01-21T14:56:00.033-05:00

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. My stash is not a "production" stash. It's collection of a couple/few lbs of this or that. 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

2011-05-30T20:25:00.001-04:00

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

2011-05-07T14:57:00.001-04:00

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

2011-03-06T00:10:00.005-05:00

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

2010-09-25T23:15:00.004-04:00

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***

Super Modified Behmor Coffee Roaster

2010-09-20T12:15:00.011-04:00

This is my Super Modified Behmor coffee roaster.

All circuit boards and thermostats have been removed and each component is now directly connected to power and an on/off toggle switch. The 2 main heating elements are now running through a variac with a Kill-A-Watt meter to monitor voltage. The drum motor has been upgraded to a 50rpm motor. A BT bean temp probe and an ET environmental temp. thermocouple have been added and a custom circuit board/ DMM meter giving BT RoR (bean temp. rate of rise)

Bean temp. probe.

I had a slightly larger drum hub made and drilled for the bean temp probe to slide through. It is lined with a teflon tube to avoid wear on the probe.

These are the bean temp. probe feed troughs. The probe tip lines up in the middle of the bean flow through the troughs. The probe is then removed to remove the drum.

****Warning***** These modifications can be hazardous. All built-in safety features are no longer functional. The warranty void. Any modifications should not be considered without a true understanding of what your doing and risks involved. Anything done to a Behmor is at your own risk. Your insurance may not cover any accidents.

Books: Scott Rao books on Espresso and Coffee Brewing

2010-05-12T12:39:00.005-04:00

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

Request for Topic Suggestions

2010-04-18T13:54:00.003-04:00

Please suggest topics for new posts here.

Darker vs. Lighter Roasted Coffee

2009-09-27T11:00:00.007-04:00

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

Home Coffee Roasting Index

2009-06-11T23:29:00.045-04:00

Home Coffee Roasting Index
Continually Updated

Home Roasters -off the shelf

Quest M3

Hottop USA

Behmor 1600

Gene Cafe

i-Roast

Home Built DIY Roasters

Modified West Bend Poppery 1

BBQ roaster RK

"Corretto"- heat gun/bread machine

Articles

Buying green beans

Storage of greens

Glossary of coffee terms

General roasting info

Willam Boot articles

Roasting Stefan Schenker

Sensory evaluation

All About Coffee, William Ukers 1922

Good coffee roasting forum threads
General roasting

General principles

1. Understanding your roaster:
heat application/transfer rates
temp. adjustments
air flow
monitoring the roast, capabilities (visual/smells/sounds, BT,ET,MET,time)
identifying and working with/around shortcomings
why, what and how to modify

2. Bean basics:
what will cause different beans to roast differently
bean density and size W. Boot article
moisture content
measuring moisture content
considerations due to processing (WP, various DP, decaf)-processing
identifying and culling defects pre and/or post roast- defects-Quaker defect-defects

3. Roasting chemistry and reactions
chemistry-Carl Staub article , coffee chemistry , Maillard reaction, Strecker degredation and caramelisation-Jim Hoffmann

reactions,
Maillard reactions-Maillard

4. Sample roasting
what is it
when to consider doing a sample roast and when to just go for it
developing a sample roast profile
how to cup a sample roast
what is the cup telling me
useful sample roast info. to use for the main event

5. Roast Profiling
breaking down the roast profile Ruling the roast,article,W. Boot
choosing a final roast level
Using the above info. from(1,2,3,4)
building a roast profile

6. The Roast
batch size
pre-heat
using the profile
data collection
monitoring the roast
adjusting on the fly.
cooling

7.Post roast analysis
visual
time after roast, when can I learn what
defect beans
cupping and identifying roasting related problems-cupping guide
adjusting the profile

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

2009-05-25T13:58:00.007-04:00

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

2009-04-30T18:28:00.001-04:00

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

2009-04-24T14:18:00.007-04:00

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

2008-12-08T23:57:00.021-05:00

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

CoffeeSnobs.com.au Celebrating 5000th Member!!!

2008-05-12T11:24:00.007-04:00

Our friends "down under" at CoffeeSnobs.com.au Coffee forum are about to register their 5000th member!!! The site is a great resource for everything about Coffee. Their membership covers the globe! I have enjoyed being a member of this group and really appreciate the dedication of those administrating this great site. I hope you take the time to visit them and possibly become their 5000th member! Congratulations Andy and all CoffeeSnobs!!!
They are helping to change the world one great cup at a time!

Buying Green Coffee Beans

2008-01-06T13:45:00.000-05:00

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

2007-11-29T21:21:00.000-05:00

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

2007-11-07T01:39:00.001-05:00

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

2007-09-29T00:48:00.000-04:00

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

2007-08-09T20:11:00.000-04:00

"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

2007-07-28T22:13:00.000-04:00

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

Jacu

2007-05-21T01:00:00.001-04:00

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

Colombian Micro-Lot Super Vacuumed Packed Green Coffee For Roasting

2007-02-16T20:36:00.000-05:00

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

2007-01-18T10:57:00.000-05:00

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

Storing Green Coffee Beans for roasting roaster

2007-01-15T16:25:00.006-05:00

I use wide mouth canning jars and a Foodsaver vacuum packer to store and keep the green beans fresh. Qt jars hold 1 1/2 pounds of green beans. When packed the jars are labeled and dated. The jars are then stored in a cool dark place. I use a dead freezer. Keeps a good stable environment. For small amounts a dead mini-fridge would work well too.

HV's pages..." Incredible Coffee Directory"!!!

2007-01-09T23:25:00.000-05:00

Directory of All things coffee worldwide. Over 1300 Listings! *Click on title above to go to site and Directory* Thanks Robert (from the Netherlands) for the use of your list.

BM/TO Coffee Roasting Roaster

2007-01-07T20:03:00.000-05:00

BM/TO Roaster
Roaster Tips To Dump Beans into Cooling Tray
Chaff Canister
Aroma Vent
Bean Temp Probe
Fan Powered Cooling Box
Sliding and Removable Cooling Tray
Turbo/Convection Oven Heater
Modified Bread Machine
Microwave cart
Roasts 1/2-2 pounds green beans
13-16 min average roast time

Cooling Box, Fan and Tray

2007-01-07T19:58:00.000-05:00

Fan pulls air through beans. Slide shelf out to fill and in to cool. (roaster and top board removed to take pic).

Beans in motion

2006-10-22T11:06:00.000-04:00

Here are the beans in motion(about a pound and a half in this batch). They are whirled around the outside of the pot. The heat from the convection oven is able to easily penetrate.

Coffee Roaster Stir Rod Drive Shaft

2006-08-28T16:58:00.000-04:00

The BM drive shaft is offset from the motor. I extended the shaft up to the roast pot with a hollow rod as shown. note (since this pic was taken; the screw at the bottom of the extension shaft has been drilled through with a bolt and nut)

Coffee Roasting Pot -Inside View

2006-08-27T00:42:00.000-04:00

Single stir rod that really gets those beans spinning like a tornado around the sides of the pot, plenty of motor power. thermometer sensor(bottom of pic).

Homemade BM/TO Roaster Coffee Roasting

2006-08-27T00:27:00.001-04:00

Home coffee roaster. Roast is very even. Made with these used parts,Welbilt model amd600 bread machine($8 thrift shop), Galloping Gourmet model 707a convection oven 1440 watts(ebay), S.S. Pot 12" diameter 6" tall(cut down from 10"), Deep pizza pan, TIF 7000 digital thermometer. Note I'm going to cut down my pot size to a height of 5" to gain more heat for larger roasts (to yeild 2# roasted/patch)