Sonofresco / Q&A / Tip & Tricks

[hootowlcoffee]

This should work for you as well. The logging was the proof that it worked and my roasts have improved because of the adjustments.

My sono roasts perfect during the winters here in Tulsa.  My DP coffees that have a higher sugar content come out with a bit more clarity of the flavors.  If I could live without a DP Ethiopian in my stash for the summer I would only roast them in the winter.  Summer roasting always keeps my heart rate a bit higher, because each roast is a tad different, and if you don't pay attention it could go bad.

I do believe it will work to adjust the gas valve and I read back how you did it, but did you find a formula for the summer?

Basically what I am asking is if my roaster is roasting fast, do I turn the valve 1/4 turn clockwise or counter clockwise to slow my roasts down a bit?

Did you try more than a 1/4 turn?

[ScareYourPassenger]

Hard to say with a 2lb sono but with a 1lb start at 1/8 of a turn and tweak from there. You need to log how it is changing so you can dial it in with more accuracy.

[ScareYourPassenger]

Time to adjust mine today, a bit late but I am scorching beans.

[Burner0000]

Does anybody sample with the 1 lb roaster?  Preferably with the sample roast chamber?

[1981er]

I too have roasts that are too fast.  Would love to dial back the gas if that's possible to roast slower.

Spoke with a guy in the Sonofresco office a few months ago, and he mentioned they will be coming out with a profiling app to run on a laptop, along with new steel temp sensors instead of the ceramic ones on new machines.  Not sure if the old ones can be retrofitted with the steel sensors.  Still haven't seen any release info on this stuff so not sure when it's happening.

[ScareYourPassenger]

I am not sure how effective the profiler will be. It needs a gas controller for the best results. To answer your question, the adjustment will slow down the roast.

[hootowlcoffee]

Adjusted the valve by 1/4 turn, noticed my dipping was greater but the roast was still a little fast.  Adjusted it another 1/4 turn, seemed like it helped!  My temperature dips were greater than my normal roasts, but the end result was nice.  Seems that my roasts are landing where they need be and more consistently, but still 20 seconds fast.  Anyone risk adjusting it even more?  My assumption is that my temperature dips would be even greater and I worry it might affect the cup.  If anyone else has tried this it will save me a possible headache, but if not, I will endure the headache and try it.  Tomorrow the cup will tell the story if I have found the promise land, or if I need to keep wandering.

[ScareYourPassenger]

Wow! That is a lot of adjustment! I would suggest logging it and seeing what the temp looks like. Also, did you mark each setting that you have tried so far? I taped a piece of paper with mark and numbers to help relate the logs to the adjustments. Be sure to log the ambient air temp so you can later figure what adjustments need to be made to help compensate.

If you don't have a way to log. What is the length of your roasts and timing relative to 1st and 2nd crack?

[hootowlcoffee]

Wow! That is a lot of adjustment! I would suggest logging it and seeing what the temp looks like. Also, did you mark each setting that you have tried so far? I taped a piece of paper with mark and numbers to help relate the logs to the adjustments. Be sure to log the ambient air temp so you can later figure what adjustments need to be made to help compensate.

If you don't have a way to log. What is the length of your roasts and timing relative to 1st and 2nd crack?

Logged it via pencil, paper and a digital temp from sweet marias. I found the burns to be longer but the dips are greater as well, this is compared to "normal".  I noticed an immediate change in the consistency of the roast.  I usually have gotten a few crackles here and there 20-30 seconds before first crack starts.  This adjustment made sure they all hit at once.  I did find that my heavy beans (guats & kenya) to be around 7:30 starting first crack and my softer (ethiopians, sumatra) were 8:15 starting first crack.  How does this time relate to yours?  In the winter months I can get first crack at exactly 8min and my consistency is spot on.

Conclusion:  I like the change so far and feel that the added extra seconds helps stabilize the temp inside the beans making the bigger dips a good thing.  My worry would be that any bigger of a dip and the beans would bake.  The temp sensor in the Sono ultimately "knows" the bean temp by measuring the air temp after the burner is off.  More "off" burner time and the sensor gets a more real (stable) reading on the bean temp.  The cup will tell here in about 3 hours after we cup them.  HOPE IM RIGHT

[ScareYourPassenger]

My first rack is almost always around 6:30-7min mark with 2nd typically around 9:15-9:45. The less gas the less dips I get.

Odd it is so different.

[hootowlcoffee]

My first rack is almost always around 6:30-7min mark with 2nd typically around 9:15-9:45. The less gas the less dips I get.

Odd it is so different.

I turned the valve a total of 1/2 turn counterclockwise.  Is that the same direction as you?

[hootowlcoffee]

So we cupped our coffees today and were fortunate enough to have the same coffee(guat) roasted after each adjustment.  The results were AWESOME!!! The affect on the cup was distinct and pleasant.  The coffee after the first 1/4 turn was distinctly sweeter and the acidity more clear.  The coffee roasted after yet another turn was similar in sweetness to the first adjustment but we noted a pronounced clarity in both flavor and body with a smoother mouthfeel.  Overall we say the adjustments are a hit and our coffee liked it as well.   We had roasted a Kenya & a different Guat yesterday as well and noticed the same affects on them.  More clear, pronounced and a smoother mouthfeel out of both of them.  We had run into a bit of a harshness when we roasted the Kenya lighter but since the adjustment it smoothed out.

ScareYourPassenger:  By bigger dips I mean that before the adjustments I would hit 200C and it would cycle, then drop to 196C before it started back to the goal of 203.5C which it made quick and inconsistent.  Now it hits 200C, cycles and hits 196C but stays there a few extra seconds making the next goal of 203.5C a slower ramp.  The dip is the same, but the bottom is longer and the ramp less fierce. 
I was hitting first crack at 8min no matter what coffee with 11:15-11:45 second crack.  Since it has turned to summer my first crack is all over the place depending on the coffee.  Usually around 7-7:30 with second happening at 10:30-11:30 depending how it's feeling.
Now that the adjustments have been made I hit First crack at 7:35 like a bullseye, where as before it was a moving target and depended on the mood of the roaster.

[ScareYourPassenger]

Ah, I got you then. Yes, the ramp back up is slower after turning the gas down. Less heat to make it rebound quickly. Also, I found when I was on the border of not enough heat that there was less cycling because it wasn't able to ramp and hit the boundaries of the built in profile.

[Burner0000]

I have converted my 1 lb model from Propane to natural gas and I am getting it hooked up today.   My question is will there be any difference in roasting or taste with natural gas?  Also the previous owner stripped the crap out of half the nuts and bolts on the bottom of the machine.  Does anybody know of a good way to get them free as well as replacements?  Maybe fillips over what it comes with?

[sgreen]

Drinking coffee with Bold Java has inspired me to quit wasting good beans by trying to be a better home roaster.

In that spirit, I have been messing around with a Sonofresco roaster. I converted it from Nat gas to LP and in the process ended up setting the valve to the recommended water column. Along the way, I noticed that you can actually get the burner to light at about half the recommended flow.

After roasting with a Behmor a couple of years at a rate of about 10 oz per 15 minutes, I was shocked to roast my first pound of beans into 2nd crack in less than 5 minutes. I then set the gas valve regulator lower (that's the screw adjustment under a small aluminum cap you can access from beneath the machine) and banged out a pound of Geisha in about 12 minutes. 

The Geisha has been pretty good; although a little risky, this was not a waste of beans. As a matter of fact -and don't tell Dave- it's nearly as good as what we cupped at his house last month.

This got me thinking about adjusting the flow with a variable regulator during the roast.

I did it on the cheap: a 0-10 psi adjustable regulator, an Ebay surplus magnehelic gauge 0-50 WC, and a handful of brass fittings from Home Depot. The regulator is good for only a fraction of it's total adjustment. 11 WC is less than 1/2 psi. The knob was too loose to permit fine adjustment so I wrapped electrical tape around the stem to give me enough friction to make it work.

Over 50 water column will blow the plug on the magnehelic gauge and vent propane next to your machine. If you try this, don't do that and if you do, don't smoke while you're doing it. If I keep this set up, I'll add a second fixed regulator for safety. It will shut off automatically when the pressure drops too fast. I'll also probably find a valve with a finer adjustment.

But I digress. I did a ramp up and drying phase, bumped the gas down to slow the roast, bumped it up again to hit first crack at 9:11, dialed it down to get a couple of minutes between first and second crack, and then ramped it up again to hit second crack at 12:48 and then finished the roast at 13:00.

The beans look and smell great. I make no claim as to the quality of this roast or this "profile." This was only an experiment to see if a cheap adjustable regulator would work in conjunction with the firmware of the machine sufficient to tailor the roast. The answer, so far anyway, is yes.

I'll post pics later tonight for anyone that's interested.