by Ken Fox on Mon Jun 08, 2009 8:29 pm noah wrote:Well, variacs are not quite straightfoward, at least on ebay. Jim, I read your review of a 5 amp variac on coffeegeek, which you stated was sufficient at that time, do you still think that 5 amps is sufficient, say, for a Poppery I? (or II, I suppose) Also, any issues with buying Chinese made? Ken, I know you said generic will do, but will it do for a unit whose amperage is technically too low?
Plus, any general buying advice or sources that anyone can offer would be of great assistance to this blind buyer!
Hi Noah,
I used to have a smaller Variac I used for coffee roasting and I believe it was a 5amp model. I must have gotten rid of it somewhere along the line and the one I have left is a 15 amp model.
I don't think that using a Variac with a Freshroast is very complicated, so I guess I differ with Jim on that point. All you have to do is to reduce the output voltage (which you can see on the dial of the Variac) to a bit less than your normal voltage, which is probably around 115. So, you'd be turning the dial so that it reads maybe 105v, just after first crack begins, in order to extend the interval between the onset of first crack and the end of the roast. After doing a couple of batches without the Variac, then a couple with the Variac, you'd figure out how to do that. A cheap stopwatch or kitchen timer would let you see what you were doing and what impact it was having on the roast. I don't think you would ever need or want to go below 100v, so the range is pretty small.
A Chinese Variac would be fine and would not cost very much; I'm sure mine came from China. They are heavy so shipping could be expensive if it comes from very far away. If you live in a big city you might be able to find one locally.
What Jim has done with his popper (PID'd, etc.) is really not something you should even think about attempting; it's basically a nerd modification.
Another possibility other than the Variac, is to try what we used to call "roastus interruptus." This would be to use the air roaster until you start into first crack, then to either unplug the roaster or unswitch it in some way for short periods of time so that you slow down the temperature rise. By doing this you could easily add another minute, maybe two, to the interval between the onset of 1st crack and the end of roast. I used to pick the roaster up with a couple of insulated gloves (like what you'd use in the oven) and shake it a bit during the time where the roaster was turned off, to continue agitating the beans. You need to be careful because the roaster will be hot!! But, it is small so it is not heavy. You don't want to do this for too long or you will "stall out" the roast which will then worsen the results. The major advantage of this technique over using a Variac is that it is free.
On balance I'd probably buy a popcorn popper over a FR, if you can find one cheaply. That way, if you don't like air roasting you won't have invested much, and no matter what you will learn a bit about roasting in the process.
Good luck,
ken
