good afternoon, welcome to mill city roasters inminneapolis, minnesota. i'm dave borton along with... i'm joe marrocco from cafe imports. and on this cold, cold winter day from minnesota we greet you. today, joe would like to take a look at: what have we learned so far? kind of a summary of the learnings that we've had to date, but from that use that as a springboard to next steps in your own sophistication. get sophisticated by firstgetting simple. so joe, i'm going to let you kick
commercial coffee roasting machines for sale, us off here. sounds great. yeah, if you've watched the other videos that we've put out over the past, oh, five or six months, we've had some that have been pretty technical, that we've gone deeper into the weeds on, and so i wanted to bringall of that together into a more simple format. we've kind of done the proofs, the work,and so now we can see the pudding. that's good.
alright, so let's just jump right in and talkabout how we would approach a coffee-- let's pretend you have a brand new coffee, your brandnew roaster, just some simple things that you can do to approach that coffee. so you've sampled it, you like it, you've bought 4 sacks of it, you've got 600 pounds sitting around, where do you start? yeah the first thing that i would recommend you do, and not only with a new coffee but alsowith a coffee that may be acting a little weird on you, is go back to the drawing boardon reading that density. so here, dave has got two brand-spanking-new cylinders, these are great. i have new plastic ones. you can grab them off amazon for like, $10 bucks. make sure they're graduated. i got plastic ones because my co-worker, aka nick, decided that he was going to redistribute the glass on the beaker i had, so plastic ones are a good idea.
did you redistribute it on the floor? all over the floor, and i had to sweep it up. so these, these are also great. if you get a lab tool it's going to weigh the same as the other tool. so these weigh exactly the same amount. so i can literally just fill them both up to 1000 milliliters and then see which one weighs the most, and that's what i've done here. so what i'm starting with here is a pacamara from el salvador. a pretty large bean filled up to the 1000 milliliter mark and, uh, i'm just going to tear this off to keep thisvery simple. lets call this my control, and so now this is a 0 grams and i'm gonna seenow that i've got a brand new coffee if it's getting more or less dense. so this is keepingit super simple and thinking about relative density as opposed to exact density. so the relativedensity here for this new coffee, which is
an ethiopia yirgacheffe that is washed, i'mseeing that this is 18 grams heavier at the same amount of volume. so what that tells me isthat this is a more dense coffee. okay. now there are some other things you want to take intoconsideration, for instance this pacamara is a larger bean whereas ethiopia is a smallerbean, so it may be a good idea to kind of counterbalance that by saying, "since this pacamara is lessdense but larger, maybe this more dense but smaller seed should start kind of similarand then that can be your initial hypothesis. so every time you get a new coffee, you want todevelop a hypothesis of how you think it's going to react in your drum. so, you weighed them out. why do you care about density? well, the density of the coffee is going to tell me how quickly that coffee willabsorb energy into the core of the seed. we
want to have nice equal absorption from the outside of the coffee to the middle of the coffee, so then we have equal release of water. andthen once we have that happen, then we can move it through our chain of flavor creating reactions. so your goal there is for the even--evenness of roasting at the center, just like on the exterior. that's your goal? that's right. yeah, and if we hold on to any moisture in the core of that coffee byheating it too quickly, if we try too heat a dense coffee too quickly, that moisture stays in the core and then we're going to skip over some of our reaction periods later in the roast because pressure builds up in the coffee, it holds on to moisture and that moisture will prevent the maillardreaction and caramelization. i got ya, so you're trying to drive to the same level of water on each bean,as well. that's right. so try to dry that
coffee seed out in a nice even way, but initially use the water that is there to pull in heat into the coffee. so nice even heat moving to the core and then nice even release of water and then we can move in through our exothermic reactions, which are the flavor creating reactions that coffee goes through. and the other one being endothermic. endothermic, yep that's where-- the difference? that's where we absorb that energy or that heat into the core of the coffee. so we'll start with endothermic reaction and that basically, to keep it simple, moves you all the way through to where you start seeing yellow. once you see yellow, that's when you're going to begin your exothermic reactions. and is it fair to saythat at the end of endothermic that bean has some energy that can be shared among the rest of the roast? absolutely, so your types
of heating are conductive heating and convective heating. in the beginning of your roast you want to focus on conductive heating, whichis a low efficiency but high absorption kind of heating, and that will allow your coffeeseed to touch the drum, carry that energy from the drum to another coffee seed. and then,once you move through that endothermic reaction into exothermic reaction you're shifting theway that you were heating that coffee. so, our thought on that is that then you want more airflow, okay. so that, that higher level of airflow is convective heating, which is more efficient. it's too efficient to use in the beginning of your roast because it'll heat the outside and then your core willnot be hot. but that high efficiency later in the roast will allow that heat to penetrateto the core even still, and create all of those
nice flavors. endothermic, all the way through end of drying. that's right. so, to simplify this a little bit more, if you have a roast...when you put that coffee in, the first thing you need to determine is what your initialcharge temperature is going to be. if you have a really dense coffee, your charge temperature needs to be higher. if you have a really low dense coffee, your charge temperature needs to be lower, okay. so let's pretend we have a really dense coffee, we're going to drop it in at ahigher temperature. that dense coffee is now going to absorb through your conductive heating energy from the drum, and that energy from the drum is going to pull that coffee up, okay. whereas, if you charge a low dense coffee with that kind of heating, you probably are going to see something a little bit more like this. okay. we like to see a little lower charge
temp. on a low dense coffee. so then, you can kind of regulate how quickly those coffees are going to begin to take off. once you see that yellow point, at that point is when you're going to make a determination as to how you want to move through the flavored development stage, which if you remember one of our former videos, i call pre-first development and post-first development. first crack just being an incidental step along the way, that you can mark so that you can go back to it for confirmation thatyou're roasting that coffee the same way. but this is developing flavor in the pre-roastdevelopment section, and then post-- i'm sorry-- pre-first development section and then post-first development section. so then, if you have a really dense coffee, you're going to make determinations as to what flavors you want out of that coffee
by roasting it a few different ways. same thing with a low density coffee. my recommendation to you when you get a brand-new coffee-- adjust it, pull the left side in a little bit. like this? sorry we're making a-- um, opposite way, sorry about that. making a slight adjustment. stage left. so if you have a-- if you have a new coffee, roasting it three different ways is a really great way to really see which direction you want to go in. so do that initial time you get that coffee, do a fasterroast, do a medium roast, and do a slower roast. if the slower roast is the one that you thinkis the best, then next time you get that coffee do an even slower roast. can you pull it in a little closer? sorry, it's just not-- the camera's not picking it up. that's okay. sorry guys.
so, the next time you do that roast, do an even slower roast. if this is an improvement, then you know that you're going in the right direction. if this is not an improvement, then you can go back to the drawingboard here, and you know that this is now going to probably be close to a new profile andthen you can start just tweaking on this in little amounts. can you do a real life example? lets just say that you've got an el salvador that's grown at 5800 feet, and you know it's really dense. can you put some rough times about that you be shooting for on a new coffee? it's going to be very difficult to put an exacttime or temperature because my roaster is probably going to be very different than your roaster or my probe placement is maybe going to be a little bit different than your probeplacement, and there are a lot of things that
vary from one roaster to another roaster.for instance, if you on a behmor, maybe some of this doesn't even make sense. if you'reon a probat ug-22, that's going to be very different than if you're on a diedrich ir-12, or something of that nature. so we can't take my friend's profile and just grab it and run with it. i've gotto know my roaster and learn what differences would come about by taking it three different ways. that's exactly right. our machines are going to be relative to that machine. they're not going to be congruent with other machines. so, the only things you can take away are-- sorry for all of the lighting stuff, we're just making sure that you can see this pretty well-- theonly things that you can take away are if i am going to heat something very quicklyin the first part of the roast and then very
slowly in the second part of the roast, thatprobably is going to correlate pretty well to whatever equipment you're on. but if i'm taking it-- if i'm putting the charge in at 420, that may correlate to your machine as 385, it may correlate to your machine as a totally different temperature all together. joe, when you use your roaster lexicon: slow start, fast finish, fast start, slow finish, are you talking about from the end of the roast or the entire roast? if i'm talking about the start of a roast, generally what i'm talking about is from the time icharge that roast until the time that coffee turns yellow and if i'm talking about thesecond stage of the roast, i'm going to talk about from yellow, all the way through to the end. now there are cases where you may want
to see a little bit faster curve through here.so maybe a little bit of a bump and then slow down. or, there may be other times where you wantto see this kind of drag and then, maybe not speed up too much, but continue at a faster pace. okay. so all of those things just are going to come through trial and error, unfortunately. there's no, unfortunately, there's no set in stone way to roast a particular coffee except for on your machine, in so i can designate to you, or i can't dictate to you i think youshould charge that higher, or i think you should you know a roast it faster without tastingit or without being there with you while you're roasting that coffee. so really comes downto your personal tastes and this is where it's important to understand the principleof that 10,000 hours of practice thing. you're
not going to jump in and on roast number 3on a new machine have the perfect roast. you know? we still, especially dave, struggle fromtime to time whenever we are roasting to, you know-- we'll weigh out the density, we'll check the coffee, we'll follow the roast, we'll smell it while it's roasting, we'll think that everything is on, and then we get the coffee or we're just like, "oh. it's kind of flat, it's not what we expected." and, our first tendency is to blame ourselves, our second tendency is to blame the coffee. we really just need to step back and try something very different and look and see if that makes an improvementor if that makes it worse and then continue to develop that coffee. one variable at a time. that's right. now, one big question that i get a lot is, okay, what am i supposed to do with all this coffee? this seems like a whole lot of coffee that
i'm going to waste before i can release thatcoffee. and in our specialty coffee world, a lot of times we think that if it's not perfect, we can't sell that coffee. and i want to encourage you that to your customer base, the difference that you're getting when you're cupping and you're really myopically focused is not going tomatter that much, okay. so this, like all things-- you've seen you do this before, is a bell curve. okay. so your level of acceptability is probably going to be a lot higher than your customers level of acceptability. let's say this is 86 points to you but your customer, you know, this may be 86 points to them. their tolerance level for your adjustments that you're making on that coffee are going to be greater than you anticipate. those of you that are at home and don't have a customer base, you've got neighbors
and the same rule that joe's applying here. they've got critical palates than you do and in our case, we've got a 15 kilograms roaster that i'm learning to roast on. well, roast number one was not perfect, but roast number two-- but, roast number two was-- roast number two was not perfect. roast number three got worse, and i remember one day i took 60 pounds of coffee down to the salvation army and they were extremely appreciative. so there's-- there's an outlet for you learning your goods. whether it's your neighbor, or salvation army, or, as joe said, some less critical patient-- customers. that's right. so if you think about this in terms of a road map as to how to go about improving your coffee, of course we want to be at the pinnacle, we want to be there, but this is a movingtarget always because your coffee's changing,
your roaster settings might be a littlebit different from one day to another, you might have colder coffee, you might havemore, you know, barometric pressure in the air. there are going to be subtle differences. so this is kind of a pendulum and if you're willing to extend yourself out to these broad spectrum, you know, experimentations on your machine, then you're going to have a much broader understanding of what that coffee is capable of, and so you're going to have a more likely ability to hit that coffee. and that'swhat i mean by up here, doing a small roast... i mean a fast roast and doing a slow roast is really kind of like hitting on both ends of this bell curve, sothen you can see: is this better than this? and if this is better than this, then it couldbe that actually on this particular roast
i may be here, thinking that i'm here but really, now i have more room, i'm narrowing in so i know, i know that this is not good so now all i have to do is worry about this part of the bell curve. so then you can come back this way anddo something kind of in the middle, so then you not, you know, constantly-- what i see a lot of roasters do, let me get frank with you, what i see a lot of roasts to do is they'llroast a coffee and they'll think that that's the curve they're supposed to roast at.and then they'll make one tiny little adjustment, a little longer, and maybe it improves a little. so, then the next time they come back and they make one more tiny little adjustment, and so every single time they roast is a little bit different, and a little bit different and then since they're doing this so often, they never really know if
maybe this was going to be better or maybe this is going to be better. but, if you go to the extremes first-- thank you-- if you go to the extremes first, then you know this will not work, this is working better, and then you can go to another extreme and then you can narrow that down. now, that being said it is important that when you were picking the variables to work with on this, that if you're going to say, "iwant a fast roast," but then you keep the air flow, you keep-- you know-- your base charge weight, you keep your charge temperature...you keep as many things as you can constant, and then change one thing to make an exaggerated change in roast. so then, if that thing does not work you can go back and say that one thing did not work, so now i'm going to make another extreme change and then go back to the drawing board. do you ever use
air flow to slow down your temps, or you dothat all with gas? it depends on the drum. if you are working on a diedrich, for instance, and you open that air flow all the way, it tends to pull energy out of the drum. if youare working on a probat and you open up the airflow all the way, it pulls the energy into the drum, so on some roasters your airflow is going to be a throttle and on other roasters it's goingto be breaks. so it really depends on the style roaster, and that's why it's going tocome back to trial and error, understanding your machine, understanding the coffee and then learning how to taste those coffees, okay. however, that being said i did want to give you guys a fun little tip that may be helpful, okay. i'm gonna flip this-- is there a cost associated with this tip? um...i'll think on that. alright. if they're willing to pay, sure.
okay, so, if you have your profile-- let me make sure i can get this nice and dark for you guys-- okay, here's your profile, here is your air temperature, your exhaust temperature, or some people might have an environmental probe that is kind of up in the upper right or upperleft part of their drum, that could also function as this. that temperature is going to be kind of, maybe above your drum temperature or maybe-- it's defintely going to be higher than your bean temperature, okay, because this is an energy delivery system, okay. so if that temperature's up here, you drop your coffee in-- charge. yep, it's charging, okay. this temperature's probably going to saga little bit because you're bean temp is cool and it's pulling energy away from that delivery source of energy. so now, the air coming out of
your drum is going to be cooler than it wasbefore you had coffee in the drum. if you can get this temperature to a certain setpoint and maintain that throughout your roast, you can use that to control the speed at which your coffee is going to develop. it's a really cool trick. this is exhaust temp? lets call it exhaust temp. okay. on some drums it might be environmental, but i really like exhaust temp. so let's say, you want to finish your coffee at 410 degrees-- you probably can't see thatat home, but that says 410. okay, so you want to finish this at 410 degrees. if you have yourair temperature stall out at 405, then it's going to take a very long time, and possiblywill never occur, that your coffee will finish your 410, because this needs to be a highertemp in order to pull this coffee temperature up.
however, if you stall this out at 4:25, now all of a sudden it has more energy than what you need your coffee to finish at, and so this is going to come to meet the temperature at a faster pace, affecting your rate of rise. so, this is a really cool tip, there are a lot of roasters out there that will simply find, like, one oftheir the easiest tools are an asset to them, is simply finding a exhaust temperature that works for a particular coffee, and then if they if they keep at 425 they know that bythe time they're hitting first crack that it, for this roast, first crack is going tocome in at whatever, 9 degrees per 30 seconds, and it's going to finish in another minute and a half, or whatever the case may be. they know that this is setting the pace for theirroast. and they're going to maintain that 425
by the use of? but, generally by the useof gas. so as you add more gas to you roast, this temperature will go up, and as you add less gas to your roast this temperature will go down, so then once they hit that temperature, then they can start adjusting their gas down slowly to maintain that temperature so that temperature doesn't continue to rise. if they see that exhaust start to drop down, they know i need to hitit with a little bit more gas to keep that exhaust up, if they see the exhaust start togo up, they know that they can pull that gas down again. so they're kind of hovering that exhaust temperature as they go throughout time in order to make sure that this beantemperature doesn't get out of control. this goes back to something i talk about earlyin another video, the horse and buggy
effect. so if you have your coffee-- is this tip number 2, or 1a? yeah, this in an analogy of this tip. so let's say that this is your coffee, this is a thing, and this is a thing they were wanting to change, right? we're wanting to change the state of this thing. well, it's the same thing as wanting to move from a to b in a car, or in a buggy. so here, we're going to pretend like our coffee is a buggy, okay. and i'm not going to attempt to draw a horse, we're just going to say that this is a horse. sothis is your horse, of course. its got four little legs and a head. so your horse is going to bepulling your buggy, right? and the speed at which your horse goes is eventually going to be the speed at which your buggy is going to go. but, let's say that this line between the two is elastic.so your horse takes off down the road and then
enough energy builds up to where then it starts pulling the cart, okay. that's the way this works. your horse is your exhaust, and its way up here.it's leading the charge, and then all the sudden your coffee is going to snap back because,it's almost like on a rubber band-- it's going to snap-- and depending on the difference between these two temperatures is going to determine how quickly your coffee temperature is going to snap back. if you have a lot more energy up here, then it's going to pull very quicklyonce it starts to move. if you have low energy up here, then it's going to pull very slowly. so thatharkening back to one of her earlier videos is why i called this and elastic relationship between you're bean temperature and your environment that bean is in or that environmentincluding your exhaust temperature and you
your drum temperature, which we don't have athermometer to read. so, that's why we look at the exhaust very carefully. joe, one of the questions i saw on a forum recently...related to turning point. yes, sir. it's really not a turning point to begin with. correct. that's part of it. but the question was, "what should i do about my turning point?" and my response was, turning point is nothing more than a data point. it's not informative to me, except for afirming or debating whether or not i've measured density correctly, and how much energy is in that machine pre- roasted, and how much energy i've applied if i'm doing the same brazil two days in a row. that's all aturning point shows me. yes, if you have the same coffee, in the same drum, and you want to drop it at the same charge temperature
into the drum, and you want to have thatroast taste the same as it did the day before, and then all the sudden you see a differentturning point-- that's when it matters. that's significant. it's significant. but, if you are roasting two different coffees on two different days at two different weights. machines-- on two different machines, it's going to be very different. if your machine is more metal focused and like really heavy, dense metals, that are going to hold onto energy for a long time and not importpart of that energy, let's say there's a lot of cast-iron involved or a lot of rolled steel,so i'm thinking an old, any of your really old machines or a diedrich machine...these really heavy metal machines, that turning point is going to be late and it's going to be shallow becausethere's more metal and more stuff that is
not coffee that is registering on your datainstrument, which is your thermocouple. however, if you have really fast machine that is more,more coffee to metal in that equation, and you have a really sensitive probe-- let's say like a loring machine or even if you're doing, if you're maybe over batching for some reason or doing a full batch and typically you do a lower than full batch-- all the sudden you're going to see that turning point be very different because your coffee is pulling more weight, okay. so, then the equation of when your coffee and machine are equivalent to your temperature probe is going to be weighed more in the coffee's favor, and your coffee is cooler when it goesinto the drum, you know, so then that's going going to weigh it, you know, down into this quadrant more. very good.
cool. joe, talk a bit about patience, move away from mechanics. a lot of people that purchased the north roasters from us are either non-roasters, before they begin--with their purchase with us, or they've come off a series of home assortment: poppers, behmors, so on and so forth. and get really rattled by all of a sudden all this flexibility in the different controls they have. yeah. speak about your own sense when you move from the barista world to your roasting world and how you maintained patience as you learned. yeah, you definitely want to simplify and set yourself up for successand focus on one thing at a time, while at the same time keeping a very practical ideaof what is possible-- what are your capabilities at any given time. and not to be self-deprecating at all, but to be realistic. so, if you are buying
a geisha that is $300 a pound and you think that in 3 roasts on this new machine that you're super excited about that you're going to nail that geisha, chances are that you're going to be very, very sad and broken hearted... and broke. and broke. i recommendbuying a practical coffee where when you saw that bell curve that i showed, it has a widermargin of error and you have a lot more room for failure, in a way that shows you something good. because, if you roast something that is just like this outlandish coffee subtly wrong, you're going to be disappointed. if you roast it-- if you have an 86 point coffee and you roastit subtly wrong, it's probably still going to be very solid and very good and then you're also going to be able to afford a lot more of that coffee so that you can practice and practice andnot feel this weight of, "i've got a maximize
the value of this purchase on my first 10roasts or else it's not worth it." so getting practical coffees and then finding ways and you can simplify. and by that i mean, don''t sit there and play with airflow, gas pressure, drum speed, allof these variables and, you know, the first 10 roasts that you do you should be focused on one thing. so maybe throw out the airflow thing altogether, just keep it open and havefun with your coffee. set it on medium and fly. yeah, do-- do only-- decide i'm only going to adjust gas, and i'm going to see how that application of heat through the coffee, through only adjusting gas on 10 roasts, suddenly changing this profile is going to affect the outcome. and then, just decide i want to learn how gas effects coffee. and then, decide-- okay, these are my three set pointson gas now that understand that, i'm gonna make
sure that i'm at, you know, a 100% gas, and then 50% gas, and then 20% gas on 10 roasts in a row at these certain times and now i'monly going to play with airflow, and i'm only going to pay attention to that and i'm goingsee how that tastes over 10 roasts. so get to know your roaster, and do that with one coffee and that one coffee, you will explore and it will not be boring to you even if it's a 84 pointcoffee. it will not be boring to you because you're going on a path of learning. and taste this with other people, make sure that you're not an island. don't take advice from somebody online wants to critique your curve only, take advice from people that are tasting, and take that advice as input and not necessarily gospel. you can see that over at cafe imports, when i've cupped over there
it's not 1 or 2 people that are hogging the coffee, there are going to be 7 to 8 sales associates that are all coming in and taking a run at that coffee. particularly as they talked about, hey, we're divided in here, how do you give us an opinion on this? what are your thoughts on this coffee? so, as joe said, don't be an island. yeah, if we have-- going on that-- if we have a coffee at cafe imports that scores 5 points from the topscore to the low score in a cupping, if we have a division in our cupping lab, that's scratchedand we re-cup that coffee with a new panel and then we will continue to re-cup that until our team is calibrated on that coffee. even if it take 6 times around, we will continue. very good, that's helpful. because those of--you are doing it for, i don't know how many millions of pounds of coffee you buy a year, and if they're doing it with thatkind of capital investment, we have home can certainly
find two or three others that can helpus with our $100 and $200 purchases. that's right. very good. the last thing i want to finish with is-- for today? for today...i think, unless we have some questions or anything like that, is as you are looking at your coffee and you're getting to know that coffee in that machine, don't only look for the blemishes, also look for the things that you like and celebrate the things that you're doingwell. if you get focused on only the blemishes you're never going to find joy in roasting coffee, because there's always going to be something that you can improve, but if you can startfinding joy in the things that you're doing well and in the way that that coffee is expressing itself, at whatever roast you did, be it a good roast or a bad roast or whatever, then you'regoing to begin to enjoy roasting in a whole new
way and you'll be roasting 10 years from now. you're getting very zen on us, joe. that's right, you're welcome. maybe then we should talk about-- it's 2017. the st. louis cardinals from last year. yeah, yes, they're going to be better this year... or we could also talk about packers they-- that's not the same. they beat dallas today, or last night, i still feel like it's today. so this is january 2017, joe and i have four months, i think, mapped out. yep. next month is roaster round table. we've got tony from spyhouse coffee coming in, mica from bootstrap coffee, joe marrocco from cafe imports, and allen from the little green truck coffee roasters in auburn, iowa, a home roaster. awesome. gone big-time up in a 2kg and i thought it would be good for some gender-balance, to get some different views on coffee, as well as, somebody that's entering it from
the small level, as opposed to these guys that do this on a bigger scale and have done it for a longer period of time.
so i want to hear her voice, as well.and i'll lend my 2 cents if joe permits me. so with that we're going to send it off. matt,thank you for running the boards, we'll keep playing with lights. joe, good to have you as always. thank you, sir. we'll see you, folks. bye bye. see you next time.
