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.
that within seconds its gone. This is one of the skills that makes a roaster a roastmaster.
Cooling. It is super important to cool your beans to stop the roasting process, or you risk going beyond that optimal end point which you have worked at to attain. I personally use a metal mesh sieve in conjunction with a leaf blower. I put the sieve over the inlet to Keys to successful roast.
There are lots of ways to roast the same bean, and really no one way is right or wrong. There is a lot of talk and words about the right way and in my opinion, these are opinions not facts. Depending on the pattern of heat application and ventilation you can change the outcome of the roast and sometimes this makes it better, and sometimes not as good. Again, this is all dependent on what you look for.
There are roast defects which we can all mostly agree on, and these should be avoided if desired.
Here is the short list.
Baked. These are beans that have had too much time stuck at the same temperature, usually somewhere near the end of a roast. It’s a common issue as near the end of the roast we may try to extend development time by lowering the heat and if we lower too much we can stall. This basically removes the moisture from the beans without changing the color gradient much. This is said to be an invisible defect, only detectable in the flavor, which will be flat or possibly metallic, and lacking any sweetness. I find that its fairly obvious when this has happened as the moisture content is quite low and the beans will feel light and airy, and will not smell very nice once cooled.
Underdeveloped. This will have a vegetative flavor and aroma, sometimes grassy. Usually this will be combined with high levels of acid which is to some palates not very tasty. I do not enjoy underdeveloped coffee and will throw out beans with this issue. I find it to be a common issue with commercial fancy shops as they are trying to get the coveted floral or fruity flavors in the roast.
Overdeveloped. I find this to be very subjective and also somewhat misunderstood. Overdeveloping coffee in my opinion means that the development period has been too long, however often folks will say that very dark roasted coffee is overdeveloped. This is actually just dark roasted coffee. Overdeveloping a roast would be extending the overall development period, without baking and without adding darkness to the roast.
Scorched. Here is something we can all agree is not a good thing. When beans contact a very hot metal surface, it can instantly darken the contacted area. This can happen when roasters are preheated or charged to a high temperature and then beans are added and not mixed well enough. At a certain level of heat, no amount of mixing is going to prevent this. I find it adds a char flavor or smoke flavor and is visible early if it happens early by looking at beans which are just yellowing. If you see darkened spots on a yellow bean, it may be scorched. The other indicator is that when following a recipe or roast pattern, beans are darker than they should be, in other words, you dump your roast just off the crack and they are already quite dark when they should be a very light roast. It can certainly happen at any time during the roast but is most evident and also avoidable during the early stages as it is visible.
Tipping. This is when the ends of the beans are darker than the rest of the bean, and sometimes have a hole surrounded by a dark area. This happens from too much heat application with the possible addition of low airflow. This is an explosion of gas inside the bean which jets out superheated gas, blowing a hole in the bean and burning the surrounding area. This is something which should be avoided as it really changes the flavor of the beans. I find this happens if I am trying to “catchup” to a roast which is going to slowly for the desired profile. Slow and steady is the key to avoiding this.
Quakers. This is not really a defect from roasting but rather a material defect, however this has the ability to alter, often negatively the flavor of your roast. Really a quality control issue, these are beans that never ripened properly. They will often remain much lighter than the rest of the roast and will have a strong nutty taste and sometimes a powdery texture. It is a very strong flavor which can become pervasive in a brew, so after your roast is cooled, pick them out. I find that when getting my beans from a home bean supplier, I find very few of these, but when I get my green from a roaster, getting it from the sack (my favorite way to get green by the way) I may have more of these. It really all depends on your supply chain, but its so easy to solve, I don’t worry too much about it.
Uneven roast. This is a roast where there is a large color difference between beans in the same roast. This can happen from a lack of proper agitation, but also from a lack of balance between conductive and convection heat. Convection heat will typically produce a very even roast, whereas pure conductive heat, such as a frying pan, or a drum roaster will very low air flow may lead to an uneven roast. This may look like a mélange, but you will likely have the worst characteristics of each color, so really try to avoid it. A note on this is that natural process beans may have a more uneven appearance, but this is due to a natural variance in the product, so don’t assume your roaster is malfunctioning when roasting naturals.
So the takeaway from all this?
Apply steady even heat, agitate evenly and monitor your process all during the roast. Use a magnifying glass to view your results, and keep track of what you are doing the entire time so when you see a defect, or better yet, when you roast with no defect, you will know how to repeat it. Often times when I get a new bag of green I will pull samples every minute or two and save them in order, then go back and really examine them. If you do this, be aware that you are changing the volume in your roaster and it may want to race as you get near the end, so if you are doing a sample roast to determine timing, you may want to not pull samples out or your timing roast will be invalid.
How to get the most from your beans.
It’s a secret. Every bean has a little treasure inside and none of them seem to want to share this info. You need to learn it by planning and often trial and error. This is why keeping track of how you created your roast is so important. Add this to waiting to taste the results, and a notebook becomes vital.
There are some basics which we can apply to every roast and typically get decent results, or at least a good enough result that we can learn from it and apply subtle changes.
When starting a new bag, roast on medium heat, straight through with no changes to heat or airflow. Dump the beans out when the crack ends. Take note of when the bean turns yellow, when it begins to brown and starts to smoke, at what point does it crack, how long is the crack and at what point does it end. Weigh in and out to see what amount of moisture is lost, or simply examine the end product to see how dry it is by feeling it. Steal a few beans right at yellow for later examination, looking for signs of early heat damage. Are there scorch marks, does the skin look weird and rougher than expected? Now do the math and determine your total development time. By definition, this is the total crack time, however actual development can happen before the crack begins, depending on how you add the heat. 20% is a target, with different beans needing different amounts. Acid is muted the longer the bean is roasted, so a bean with enjoyable acid may do well with a shorter development time.
A roast done this way might look like this:
6 minutes yellow
8 minutes brown
10 minutes done.
This is going to be a bright, fairly acidic and possibly underdeveloped roast, but we will have learned a lot from it.
The key to flavor development is to extend the roast only during the time when it matters. And when it matters is during development. Damage can occur anytime during the roast but building flavor only happens once the beans are starting to brown. Using the above roast as an example, you can drop your heat down at 8 minutes, just when the smoke starts to appear and this will reduce your rate of rise dramatically to where your crack will happen at 9:30 or perhaps 10 and then go on for a full 2 minutes or more. I personally really like roast times of 12 to 13 minutes for most beans.
When reducing heat to extend development, it is important not to stall the roast or worse, develop a negative rate of rise. This is a period of a little stress, because the development period is so important but you can ruin your roast if you do it wrong.
The hive roaster makes this pretty easy by learning to calibrate your heat source with the roaster. A key thing to understand is that the smoke incinerating properties of the roaster only work with a certain amount of heat input. This directly corresponds to rate of rise. If your hive is actively incinerating smoke, and you have a full load of one cup of beans, you are likely still progressing. If the roaster is not incinerating smoke even when held mostly still over the flame (careful of the scorch!) it is possible that you are stalling. At some point, this may be what you need to do because you are running too hot and need to put the brakes on, but as a rule, keep that rate of rise positive. This can all be made a little easier by adding a data dome, but its not the final solution.
At some point early on when you get your roaster, figure out where low is. Do this by waiting until the roast is actively smoking, near or at crack and move it away from the flame and view the amount of smoke produced. This allow you to see how much smoke is actually happening vs how much is being incinerated. Now, put the roaster back over the heat and reduce your flame until you see that same amount of smoke. Take note of the flame volume, control knob position and your height and now you will know where low is. This is where to lower the heat to develop.
Momentum. This is an important thing to understand. With a fully loaded roaster you have 6 ounces of beans and about 11 ounces of steel. When this is hot it will retain its heat for quite a while. It will even continue to increase in temperature without any heat input. This is based on the principals of thermal mass. When you are trying to slow the heat down to develop your roast, you need to anticipate the crack and start early. Once you begin crack, its really too late, so as you begin to brown, really pay attention to all your senses so that you know when that crack is coming and you are able to reduce the heat at just the right time to get a nice strong crack and full development.
In my personal opinion, coffee which has not cracked is not roasted enough, however there are countless coffee shops out there to prove me wrong. Beans are getting lighter and lighter as fruit forward, citrus and floral flavors are so popular. It is difficult to get this right as just stopping your roast early when the beans are yellow is not going to work out and will taste gnarly. “notes of rotting fruit with an astringent sandpaper finish” is how I would describe this. So to get it right, you still need to develop your roast and mute the acid, you are basically just bypassing the browning. The way to accomplish this in the hive is to reduce the heat very quickly after yellow and try to roast for as long as possible without increase the end temp too much. Don’t worry as much about baking when doing this as there is going to be plenty of moisture left. Again, this is pretty tricky to get right and it’s a very tight balance between delightfully fruity and compost. It does not have to be so severe however to still gain a floral or fruity flavor, and even fully roasted, fully cracked roasts can retain a nice balance.
Timing at the end of the roast. The time when you dump the beans is super critical and really needs to happen at the right second. Watch a really good commercial roaster at the end of roast and they will seem almost frantic pulling samples and smelling the trier, then suddenly dumping the roast. This is because they are smelling for a certain smell and they know the leaf blower and can cool beans as quickly as 30 seconds total time. This may be a bit extreme, you can use a variety of different ways to cool them, and at the same time remove the chaff. The way I do it when I don’t have a power blower is to use two sieves and dump from one to the other, using as high of a drop as possible. At the same time, rotate around in a circle so that the beans fall straight down and you catch them, but the chaff will fall slower and not into the lower sieve. I’ve also cooled pretty effectively by floating a bowl in another bowl of cold water. Put the beans in the floating bowl and they will cool pretty fast with a little gently stirring. Folks used to spray a light mist of water onto beans to halt the roast, I have no experience with this. Until I come up with a cooling tray for you, this is up to you to figure out, so be creative and share your techniques.