here is some basics in regards to roasting on the cascabel
How to roast modern, high end coffee shop style coffee with Cascabel by Hive Roaster. If you are looking or a darker, oily French roast style, please read this anyhow, but follow the instructions in the darker roast section as it will save you roasting time.
This roaster is designed to be able to simulate the results from any commercial roaster-fluidbed, hot drum or hybrid
Here is a list of what you have control over.
Music. Keep it funky.
Agitation. This is like drum speed. More agitation creates a very uniform color and clean flavor with results similar to a fluid bed or hybrid, less agitation will be more variable and may provide smoky, charred or roasty flavors similar to a hot drum.
Heat input. You can control this in two ways. First, by gas valve modulation turn it up or down. The second is by roaster height. The higher the roaster off the flame, the less conductive heat is available, but convection heat may increase. This is due to aerodynamics involved in the flame shape and the shape of the roaster. Gas flames appear fairly flat in shape, but a look at a thermal imaging camera will show the heat pattern to be very much like a candles flame, the heat gathers to a point at the top. Holding the roaster at the peak of this heat pattern will add a lot of convection air to the beans.
Air flow. As explained above, due to the aero and thermal dynamics, changes in the distance above the stoves flame will greatly vary the amount of airflow inside the roaster. Generally, the lower and closer to the flame the lower the flow, the further from the flame the higher the air flow. One technique I employ sometimes is during development I may increase the gas, plus increase the roaster height. I would do this because I want a lot of air flow to keep the smoke off the beans, but do not want to stall the roast.
Overall roast time. You can roast as long as you want and as short as about 6 minutes.
Charge temp. You can pre-charge or not, its up to you. Pre-charging changes the profile and typically will shorten the overall roast time. I am undecided on the value of this in regards to roast quality. It is important when matching profiles as it allows you to accurately copy past roasts, if that is your desire. Commercial roasters are almost always pre-charged, but consider they are running multiple roasts and need consistency, so starting with the same temp removes that variable.
Development. This is the period of time during the roast where the temperature is typically reduced and the beans rate of rise slows down. This is often a determining factor to overall roast quality and needs to be considered and planned out.
Endpoint. You can drop the roast whenever you desire and immediately begin to cool.
Here is a run down on the entire process.
First, please play music while roasting.
Open the roaster and brush out any remaining chaff. Do not clean with water unless deep cleaning is desired. I have personally never cleaned a roaster other than brushing except for one time to learn how. Soaking in hot water in conjunction with an oil solubilizing cleaner such as urnex or other espresso cleaner will remove all deposits and make the roaster appear new, other than the golden hue which is a result of heat input and is permanent unless you were to re polish the unit with an abrasive.
Measure out your beans. This can be volume or weight. Results from each method will vary due to bean size. You will learn which is best. I use volume. One measuring cup is my go to and balances the process very well. With most beans this is just shy of 6 oz. This also provides me with three French press pots every two roasts which works well for me. The more beans the more heat you can use. With less beans, the heat reacts quickly and is more touchy and I find it more difficult to achieve proper development. The other factor to the amount you use is that you are holding this unit and agitating it constantly for the duration of the roast, and where one or two ounces don’t sound like much, after 9 minutes of constant action you can really feel it, although you may not want to admit that a single ounce is making it too heavy.
Preheat the roaster or don’t. Its up to you. If you preheat, don’t over do it or you will blacken the roaster and potentially damage the stainless steel by burning out the nickel. The metal is very thin and heats quickly, so take it easy, use low heat. Be careful when removing the lid, it will burn you unless you use a towel or gloves to remove. Preheating the roaster reduces the overall roasting time and can has the potential to change the flavor. I can get excellent results either way and tend not to preheat.
Decide what you want your profile to look like. More time tends to lead to smoother coffee with less acid, but with more blended flavors. Short roasting time results in a bright acidic cup with prominent individual flavors. How much of your roast do you want to be development? 20% of the roast time is the industry standard, its totally up to you. I tend to develop longer than 20% with very good results, but I am usually going for a very smooth, low acid roast. Really plan it out if you can. If this is your first time, don’t worry too much, you will learn a lot from this experience even if you aren’t super stoked on the result. I wouldn’t even try to develop, lower the heat or anything. Start at a medium heat and go for it. If you aren’t going to develop that first batch, let it run a little darker than you might normally want to be sure that totally done. If its very light and not developed it will taste grassy and make a scummy cup of coffee. Nobody likes a scummy cup.
To determine the heat input needed will require a bit of experimentation. Assume your first roast will not be very tasty, but may be the most valuable as you will learn from it. Stovetops put out a huge amount of heat and the cascabel can take it, but your beans may not. It may take a few roasts to really get to understand the heat. The key for me is end of drying phase. This is when the beans change from green to yellow. Directly before they begin to yellow, the green will become vibrant. I look for this to happen just prior midpoint of my overall roast time. Most of my roasts are between 12 and 14 minutes, so I want to see end of drying at be at 6 to 7 minutes in, starting with a cold roaster. Preheating can drop a minute or two. Monitor your beans constantly during the process with a flashlight. If you see the color begin to brighten to that vibrant green and you are 3 minutes in, you are too fast, lower the heat. If at 3 minutes the beans are pale and unchanged, the heat may be too low. You’ve still got time to correct. If you get to 6 or 7 minutes and end the drying phase, you’ve got a great start. If you continue this heat without lowering, you roast will crack hard before 10 minutes and depending on your goal, may be over shortly after that. The next key waypoint is when the beans are browning and you see what appears to be a slightly darker oil coming to the surface. The bean will appear somewhat uneven and glisten slightly. This is my indication to lower the heat as low as I can to develop. Its likely 1 minute or so before it would have cracked. If I am late I will pull the roaster off the heat for 10 seconds or so to slow the process. Now simmer. If you have a thermocouple you will see a rate of rise somewhere below 10 degrees per minute, maybe even lower. If the rate of rise goes negative, this may adversely affect flavor by baking, which is pretty gross, so keep the heat on the positive. Once the beans are producing smoke, you may not be aware due to incineration, so pull the roaster off the heat and watch for smoke, this is a very valuable tool. Once you are sure your beans are actively smoking, lower the heat until you see smoke exit the roaster. At this point you roaster will not heat positively, so you will need to increase until you see incineration. I use this to determine the lowest setting on the roaster, perfect for gentle development. Do not do this at crack as there is so much expanding gas happening that the incineration process may be overwhelmed and so this test will not be very accurate.
Now that you have begun development, continue to monitor the aroma, and you will begin to smell the caramelization of the present sugars. These sugars are only there for a short while and too much heat will burn them away forever. Proper development will caramelize the sugar and provide a very flavorful, sweet cup. Now you will need to decide when to drop your beans. This is up to you. The roaster will give you whatever color you want. When you are sure the roast is complete, turn it upside down into your cooling tray of choice and begin to cool. I use a coarse mesh sieve in conjunction with a leaf blower. On my setup the sieve sets onto the intake of the blower. I run this on high for about 1 minute and mix. This will also shoot chaff all over your neighborhood, so please consider this when aiming. Any fan will cool the beans rapidly, and just dumping them onto a plate and spreading them around will suffice. As Hive Roaster grows, expect to see a full line of cooling equipment as well as other accessories.
For the darker roast.
Traditional dark roast is pretty easy. Load the roaster and apply heat. For a traditional oily French I am only going to be roasting for 10 or 11 minutes. You can apply quite a bit of heat early on but be aware that the dark end color is going to mask damage you have done in the early stages of the roast. If you see the beans go through an orange phase, you have burned them early. Be gentle during the drying phase, try keep it to at least 5 minutes, then put the power to it once they begin to yellow. The convection heat available in the cascabel can damage the beans early on. They will turn orange and have a dull rough appearance when they are roasted. You may not notice this once they are very dark but it will affect the flavor so be careful and monitor the process closely. I often dump a few beans every minute or so, or at certain temperature intervals so I can go back and look at them to see damage.
Development is still important with darker roasts, but the char flavor is overpowering so nuances in the bean will be lost regardless of development efforts. You may use crack or after crack as determining factor as to when to begin development. The hotter the roaster and beans the longer it will take to begin development as there is lots of heat to dissipate, so it will take experimentation to get the timing just right. Monitor the beans carefully as they darken as they can go from robust to charcoal very quickly at high heat.
A more modern approach to the darker flavors without such a dark, hot endpoint is to use the hot pan to develop a small amount of char on the exterior of the beans without pushing the endtemp super high. The way to do this is to follow the directions for a modern, lighter roast, but do not agitate the beans as aggressively as you approach the development period. This allows for more contact time with the hot metal which will add a distinct charred or roasty flavor, while still allowing the more subtle flavors to come through. This is done by commercial roasters as well, by slowing the drum speed and often lowering the airflow for a while. I see many espresso blends done this way.
Bottom line here is that the roaster will give you whatever results you want, but you will need to learn the process. This is analog, not digital. Manual not Automatic. No power steering or autopilot here. Take notes, save beans and match them up with profiles. Soon it will all become second nature and you will know just from the smell what is happening and how to react.