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tips - cheap unit to measure voltage/current/kilowatts used by roaster
Hey all,

I've been roasting on my I-roast 2 for about 3 months and loving the coffee. (Favorite so far is shown at the bottom of this post)

buy an energy meter. I have one because its a great way to measure the electricity users in your house, like old fridges, leaving stereos or computers in standby, etc which can suck energy.

The reason I think it is worth mentioning is I kept reading about VOLTAGE and how it is different for everyone... changes the roast times, blah blah, big variable in the roast, etc.

Well, I wanted to throw that idea out there, for anyone on a crappy power system who might experience voltage swings.. I use the SAME PLUG everytime.. Because what I found is the LENGTH OF WIRE TO THE PLUG changes the voltage.. think of it like a water hose. the more water hose you have, the less pressure at the end of the hose.

With my system I get the following readings:
Not operating: 122 volts, 0 amps
At startup (full speed on fan): 116.5-117 volts, 12.38-12.4 amps
During roast (fan at reduced speed): 116.5-117 volts, 12.1 amps

I have found the VOLTAGE DOES NOT VARY, and so I've eliminated it as a variable. I also suspect that this should not be an issue for ANYONE, because it seems to the me that the power drawn by the unit does not change.. If voltage is lower, it pulls more amps, but the kilowatts, or power (volts x amps) will stay the same.

If someone finds that it DOES affect their roast, then I hope this unit can help them get a handle on their roasts.

Happy roasting!

Nashville, TN

Well, now that I posted my voltage does not change.. my voltage CHANGED. weird.. What happened is usually roast at night, and appliances and AC are off.

For whatever reason, the dry running on high heat drops the RESTING voltage at my plug a FULL VOLT. With one of my A/C units on is another 0.5 or so. I DID NOTICE A LONGER ROAST TIME.. And more importantly, the amps while roasting went down. and usually the onboard temp is already reading close to 450, but it was having a hard time getting over 410F until it slowed way down on airflow..

Roast No: 7
Coffee Name: Peru Norte
Coffee Notes: Shade grown. This coffee is very high grown in northern Peru, where many of the the organic coffee growers have been certified organic for over 2 decades. Grown from heirloom arabica typica cultivars which require a heavy shade cover to thrive. This area is also home to many rare birds such as the critically endangered White-winged Guan and the Peruvian Plantcutter. Bird guano is used in the coffee plantation as organic fertilizer. A wonderful South American coffee: a soft acidity, a very smooth medium body, a pleasing sweetness, and finishing with a subtle smokey flavor. Well suited to medium and dark roasts.

Certifications: Certified Organic & Fair Trade
Transfair Profile: no CO-OP listed by bean supplier (
Temp Profile: memory profile no. 3:
340 F, 2 min
390 F, 3 min
450 F, 4:45 min
[note: profile 3 has 6 min @ 450F. Stopped at 1:15 left]

Weight (pre) 140 g
Weight (post) not observed
Roasting observ.: 1st crack from 6:15 to 7:30 min roasting time (started 1:15 min into 450 F roast temp). 2nd crack not distinct or observed. Evenly oily surface, but not extremely oily. Dark chocolate color.

Cupping notes: Complex cinnamon/choclate flavor and smokey aromatics.
General notes:
Edited by craftbrewer on 10/01/2006 5:55 PM
This Kill A Watt meter, last time I looked I believe radio shack sells them too. I have seen them on E bay as well. yes they are a very nice little meter which will let you see how much your voltage and amperes are when roasting. I also seen these in Ace hardware stores, and don't quote me but I believe it was Home Depot who occasionally has them too.

I am using a different meter which has a bit more data on it and logs to my computer in one second intervals if I wish in case I want to get really geeky with it. That meter is usually on my inverter and while I normally do not have voltage issues, if I need, I plug into the inverter and it will automatically adjust the voltage as the load swings.

Yes a few volts can make a big difference in some instances.

Thanks for posting this info ..

Bean there Done that, donated the T-shirt to the Church of the Second crack.... St Beanyface
craft, one thing you have to remember is. your plug is brass, and probably a bit tarnished. the plug receptacle is mostlikely brass, it slides in between the connections in your plug and then several amperes are flowing through it to your roaster. Believe it or not your results can change a bit from each time you plug or unplug it depending on how well the connection is made, how much surface area, how tight the leads are being held to each other etc etc... a slightly loose connection can easily drop a few volts.. especially with that kind of amperage flowing through it.

Edited by Ascholten on 10/01/2006 10:05 PM
Bean there Done that, donated the T-shirt to the Church of the Second crack.... St Beanyface
for real control with voltage shop ebay for used multi-meters and variacs to control the voltage manually. You can really follow heat profile with the right toys. gerry
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