Helping for Cold Weather Conditions

[Copyright_47]

So I have been meaning to write this for 2 month now. Sorry to those who could use this as just ONE point or place to start getting/keeping your profiles on track.

Many roasters like myself do not have the privilege of roasting in a climate controlled facility nor in tempered climate. Talking with several unnamed fellow roaster about how things were going, a few were noticing cup profile shifting while they have adjusted the heat/air application to compensate for ambient temperatures.

Something that may seem so basic to some folks, be it that they learned it on their own via cupping roast, adjusting one thing at a time, or from a fellow roaster. Be it that there are many things to keep in mind in order to stay ahead of the roast in changing weather conditions which influence how heat and air application need to be assessed and applied, the one thing I am touching on here, from talking to those who have had such large shifts, is not taking into account that is the indoor ambient tempurature will effect post roast- the time it takes to cool the beans once discharged into the cooling tray. Beans in a 60 degree warehouse in the winter cool much more quickly than in the summer when it is 100+. Post development time, understanding that the beans are still roasting/developing after they are discharged. Example, if you, by profile, discharge normally at say 407 degrees to the profile you follow that may have been created in warmer conditions where your cooling time is 3 minutes, in cooler conditions, depending on how cold it is you may want to drop that a degree or more further, OR extend you development time during the roast either pre or post crack. Every bean (origin/lot) may prefer using a different method mentioned above or a combination of either. The main controlling factor you the compensation to your roast and or profile should be to your roasting/tasting/quality control/company preference/profile wants or needs.

Now always keep in the back of your head that there are many many more things to take account when firing up you roaster for your first batch of the day, humidity, outside temp, wind, barometric, raw bean temp, music playing in the back ground, ect. The intent was not to teach nor preach all roasting here, just one thing, a big thing for cold roasting, to help ANYONE who this may reach that did not take this into consideration, or for those who do not have the ability to just play with coffee, roasting, experimenting on their own time and with their employers raw product.

-Mike / Bean Slave

[PrescottCR]

In case this helps anyone- on the spreadsheet where I keep my roaster time on log I have a column for green bean temp for this very reason.

I bought an inexpensive indoor / outdoor digital thermometer that has a probe for the outside temp. Instead of putting it outside I stick it in one of my bins of green coffee. Since it's immersed in the green coffee I get a good estimation of the temp. The one I found also displays the relative humidity. At 5000' elevation in Arizona it's always LOW. So all my green gets put in grainpro bags or bins on arrival.

I don't do any math with this temp number, but it does remind me where the green is so I can adjust accordingly which means more of a gut instinct change in charge temps or flame. Oddly enough the beans will warm up during the winter once the heater starts running as it's in the same corner of the warehouse.

As for the summer- when I was at a RG retreat a few years ago some Roasters there mentioned using a room A/C unit for cooling beans claiming it increased sweetness. Once things get warm enough in the warehouse I use just such a device with it's cool air routed over the cooling tray via flexible ducting. So I can keep my finish temps reasonably close. This is the kind of A/C unit that has wheels, sits on the floor and is supposed to exhaust out a window via flexible tubing.

IIRC the A/C unit was around $200 for the highest BTU rating I could find. It does draw enough electricity that I had to make sure the circuit it is plugged into didn't have any other big draw items on it. I do believe it helps in cooling, can't swear to increasing sweetness as I was adjusting all kinds of stuff in my roasting at the time.

As you might suspect I'm in a barely climate controlled warehouse as well.

[Copyright_47]

Hey Richard,
That is really neat having a temp probe in the green coffee for that reason. I can see how that would get you a little closer in idea of the bean temp prior to roasting on a day by day basis. We have a small weather station on the roof of our warehouse that will will provide wind, wind direction, outside temp, outside humidity, barometric pressure, and precipitation. Also will provide inside temp and humidity. I think the system was about $300 and has been worth every penny. Mid to late spring here is storm season and in a single roast it can go from 80-90 degrees with 95% humidity to 65-70 degrees and 15% humidity outside with in 2 sometimes a single roast. FUN!!!!
A small AC like what you mentioned, with a rigging to blow over the cooling tray would be great. That would so well with summer roasting. As far as making the coffee sweeter, I do not know how much effect you would get as you mentioned, but know it would have a crisper, cleaner cup.

Great input.

[PrescottCR]

Glad to help!

Here's a pic I took for my Facebook page, you can see the A/C unit sitting unused on the left. There are ingredient bins containing green in the shot too, that's where I bury the temp probe. I get temps from mid 60s during the winter to mid 80s during the summer. It turns out the heater for our warehouse is in the same corner as the roaster, and the green actually goes UP a few degrees during the colder months when the heat is on more frequently. Something I wouldn't have guessed without that temp probe in the green.