how to roast green coffee beans yourself, been looking at the different stages ofroasting, and joe is going to take us from first crack and beyond today. so joe,i know we're going to get into science, so i'm going to sit back and relax. it'sall yours, my friend.
first crack, including second crack andbeyond. so often beginning roasters especially, are roasting well beyondfirst crack into those darker realms of coffee that we call second crack. thereare -
that is so ubiquitous with all of thecoffee that you taste. and the way that that ubiquity happens is throughroasting all of the coffees beyond first crack and into or maybe even beyondsecond crack. so, in other words you can take all of the dynamics that are inthese various coffees and bring them to one homogeneous characteristic of just"coffee." and we don't really like to do that in specialty coffee. we considercoffees to be unique based on where they're grown, how they're processed, thevariety, the altitude, and that's why for the most part, you'll hear dave and iteach that you should never move too far into second crack, because you're takingall of that lovely
characteristic - all of the things youpaid a little extra money for - and you're homogenizing that. you're burning it outof the coffee. however, there are times and places whereroasting a coffee more darkly is appropriate, and as we have said in thisprogram before, roasting is not a moral endeavor.
target. so that's why today we are goingto talk about second crack, we are going to talk about roasting a little bit moredark, because that may be something that you at some point want to do, and youshould have the tools in your toolbox to execute that, execute it well, and execute itrepeatedly. dave and i were speaking before this, and even he and i havediffering opinions on how to approach second crack, and we're going to get intosome of that, too. so, what happens? ok, so here you drop the coffee in, you havethe turning point, it goes through yellow, you go through your development timeprior to first crack, development time after first crack, and then all of thecompounds that are in the coffee,
they continue to go down their domino effect, their chain of reactionsto the point where they have dissipated so much, that eventually they leavebehind the carbon skeletal frame of the molecules that they once were. now, within coffee, there are a lot ofresources out there that use terminology that i have listed here, and i want youto know that this is actually not what's happening within coffee, generally.generally, these three things need very high temperatures, and they're happeningto much more complex molecular structures that are in organic material.like for instance, dry distillation,
carbonization, and well, all of these, happen in placeslike a volcano or something like that. usually there needs to be a void ofoxygen. now, there are subtle snippets of these reactions that are taking place incoffee, but i'm going to simplify all of these - i'm just going to cross these out,and i'm going to write charring. this is what's happening to your coffee asyou're moving it forward through the roast. of course, some of these things cankind of happen, but these are very complex physical things that take placeat very high temperatures. so we're going to focus just on charting, becausecharring not only speaks to what is
physically happening in the coffee, butit's also speaking to the flavor that you get out of the coffee and the visualcues that you get within the coffee, so it's a really good term. and what doescharring mean? well, charring means that you are getting flavors of burning. ifyou take a steak, for instance, and you sear that steak off on both sides,and then you cook it to where the middle is nice and medium rare, you will still get some flavors ofcharring, and that adds to the complexity of that piece of meat. it adds to theflavor. you go through the maillard reaction on that piece of meat, and thenpast that, you start to burn up those
compounds that are on the exterior partof that piece of meat, and you get a little bit of carbony flavor. carbonyflavors, charring flavors, are bitter. they're usually pretty much the same,whether you get a charring flavor on a piece of meat or a cookie or whatever itis, they're pretty much the same - coffee. but they add to the complexity of thatcoffee. so there are different ways that you can go about approaching thatcharring, and whether or not you want to preserve the flavors that were thereprior to the charring, like you would on a medium rare steak, or whether you wantthe coffee itself all the way through to taste more on the charred side. so, why wouldyou ever want to do that?
well, if you get that coffee that isdefective, or there's something it's getting too old or there's somethingabout the coffee that is negative, you can actually cook those flavors out bychanging those compounds that are making the negative flavor into flavors ofcharring. some people prefer darker roasts of coffee, because they actuallyenjoy this flavor in a big way. and so they prefer dark roast because, charringis a flavor that we here refer to as robust or strong or intense. it'sone unique flavor that can be overpowering in the cup.
customers that are asking for those oilybeans.
one, if you go through first crack andyou continue to move very quickly into second crack, you can roast the outsideof that coffee--those outside layers will start to get that charry flavor, but theinterior of that coffee maybe kind of protected because it's not moving quiteat the same speed as the outside. so you hit that second crack pretty hard andthen you drop it as you move into that second crack. and you canpreserve some of the natural flavor of the coffee, that you developed into thecoffee, while at the same time adding that char flavor to the outside. so, itwould be more like your medium to medium-rare steak approach to charingthe coffee, or if you slow it down as
you're moving into second crack--byslowing it down you can kind of break down some of the unique characteristicsof a coffee, almost to the point where you can even bake if you do this moreexaggerated, and then bring it into second crack nice and slowly and thenyou get a more unilateral flavor and you can hit the same target much more easy.it's kind of like landing a plane. if you land the plane very very quickly, it's very hard to hit the runway in theexact same place every time because that last moment of landing the plane is veryvolatile. roasting coffee into second crack is very similar. if you move invery quickly,
it's very hard to hit the exact sametarget of flavor every single time. the further into the roast you get, the morea small amount or a small range of change will make an impact in the cup. ifi drop a coffee a minute after first crack and then a minute and 10 secondsafter first crack, the difference is going to be a lot more subtle. however, the same coffee doing that insecond crack, if i'm moving fairly quickly, the change is going to be very great, because those molecular reactions are moving at a much faster pace and i'll gofurther down that chain of reaction much more quickly. so, what else is happening?why in a second crack even happen? so, first crack we know it's from thebean getting inflated from all of these
chemical reactions that are taking place,and the seed is swelling up, swelling up, swelling up, to the point where thepressure builds up so much so that the the coffee seed bursts open and allowsall of that gas to release. however, once it has released that gas, now the bean ismore porous and open, and anymore gases that are being built up in the coffeeare starting to gas off very quickly. however, as we move through second crack the actualcellulose structure of the seed itself begins to decompose. in thatdecomposition adds for a lot more gas, especially carbon dioxide to startbuilding up on the inside of that seed.
and with that structural integritybreaking down, it doesn't really need to swell the seed anymore. it's sobrittle that'll just start crackling and and breaking down the actual cellstructure itself. if you move quickly into second crack, you'll see those littlepucks fly off, we call that chipping. those little disks that pop off, they'll blastoff the side of the coffee and leave a little crater, that is something thattells us we're moving too quickly and much more violently or volatile-ythrough that phase of second cracked. so slow it down, if you see that. that isactually considered a roast defect by the scaa and others. so slow it down, keep it chill.
too much convective heat will do that.
what is the oil? are you creating the oil?where is it coming from? as you open up that seed more, and the pores of the seedbecome more open, which is through the degradation of cellulose and alsothrough the swelling of the seed that took place during first crack and beyond, you are allowing for those large fatmolecules that have now broken free from where they normally hadbeen. you're allowing them to now just ooze out on the outside of the coffee.that oil will go bad very quickly. a darker roast is also open to oxygenationvery quickly. a darker roast is also open to leaching its carbon dioxide much more quickly. all of that is to say a dark roast will stale very quickly.
ok, so a lot of the more nostalgicflavors that we think of in coffee are actually also stale flavors in coffee. soi do highly recommend that if you are doing dark roast, that you use those darkroasts very quickly. if you don't, the oil on the outside becomes rancid. somestudies shown that rancidity of oil in coffee takes place within about 30seconds. of course that's unavoidable. if you have the coffee out on the cooling trayit's going to cool with in that amount of time. rancidity is simply theoxygenation of the fat, of the oil itself, which can cause off flavors. so i dorecommend that if you are going to go dark try to get the the flavor ofcharring on to the coffee in a way that
still preserves some of the flavorwithin the seed, while not allowing a bunch of oil to come pouring out. sohitting the first part of second crack to where you are getting a little bit ofthat charring can bridge the gap to your drinkers that are looking for a morenostalgic cup, while at the same time promoting the longevity of that coffee,and allowing that coffee to not go stale in a very quick way.
have a theory, and i want to state veryclearly that this is a theory. and this is actually the first time i'mdebuting this theory publicly. ok, so i --got the microphone?--
weeks at a time, that the seed inside ofthat cherry is actually beginning the germination process. so it's beginningthe malting process. and what malting means is that all of those compounds that havebeen stored up in the cellular structure of that seed are beginning to beunlocked, and they're beginning to become more soluble. which of course, when weroast coffee we take a non-soluble seed, that green seed, put it into a roaster,use heat to break down those molecules so that then they become soluble. in thecase of malting, like if for instance barley and wheat for beer, you allowthe seed's germination process to break down those heavy starches and begin thatprocess of making that product soluble.
so, my theory is that with a naturallyprocessed coffee we're already a little bit farther along in that molecularchain of breaking down those compounds. and so since we're furtheralong there, once we get the first crack we're actually further along in theroasting process than we think we are. and so instead of thinking about oh ishould drop this a minute after first crack, because we are further along thechain of development. we're still trying to abide by these oldhierarchical rules that have been dictated to us, that we should go aminute and a half to two minutes after first crack, and so we're already overroasting the coffee when we
should have listened to the cuppingtable that tells us that's over roasted. what do you do if it's over roasted? well,roast it less. so don't be afraid on a natural process coffee to slow thingsdown, and to roasted a little lighter. know that second crack may come a timewhere the coffee tastes more dark already.
"yeah we know some things about coffee,but one of the fascinating things about coffee is there so much yet to beexplored."
oxygen present. and so, we had twodifferent types of breakdown of these two molecules and so therefore we havetwo different flavors that were created due to that. it doesn't matter, because atthe end of the day you're breaking it down to more carbon base regardless ofwhether there's oxygen or whether there is no oxygen present. so that's why forus to be more exact we actually have to be less exact within the general senseof roasting coffee. these are extremely specific reactionsthat take place under very specific types of environments, and so we don'tknow exactly.
of that molecule that is given off,generally in the form of some kind of gas, most likely carbon dioxide or h20.and so, as you move forward here it is the energy from the fire, from the drum,from other seeds that have more energy than the seeds were speaking of, whetherit's conductive or convective energy, that energy is hitting a molecule at atemperature that is reactionary for that molecule, that molecule breaks. thatbreakage does not happen prior to yellow. and when it does happen we refer tothose chemical breakdown processes as the maillard reaction and caramelizationprimarily, but there are also a lot of other reactions that are taking place.
are a home roaster and you're trying todo something experimental and like one off, one time, and trying differentcoffees to see how that particular coffee tastes the best at a dark roast. if you want to do thatway, this is kind of what your your rate of rise should look like. it should kindof come up you know and then kind of come down and then do that. ok. so here you have a control. instead offocusing on slowing this down too much after first crack, what dave recommendsthat you do is don't worry about development time here, because all ofthese subtle nuances that you want to get out of the coffee-- these are nuancesby the way all-- of these subtle flavor
nuances that you want to get a coffeehave tapered off at this point anyway. and what you want to get is into secondcrack without baking the coffee out too much. so then you would drop the coffee atabout the same rate of rise momentum that you would have dropped the coffeewithout it going to second crack. is that correct?
like this where you do have a divot. obviously don't want the flick, ok, you do have the divot and then itcomes down, and then you should just continue tokind of ride that out until you hit the point where you want to stop the roast. you may actually, in some cases, see this plateau or go up a little bit as you getfurther into second crack, as long as you're able to control that and hit thesame mark every single time. if your production roaster it's very importantthat you're hitting the same mark every time. there's not something called abetter or worse roast for production roaster. there's a right or wrong roast.right roast is that you've hit the mark
that you wanted to hit, the wrong roastis that you did not hit that mark.
to ourselves if were a home roaster, whoeverit is that's going to brew that coffee, we want them to have a successfulextraction which leads to a successful flavor experience. so when you startgetting deeper in this roast you're affecting not only flavor, but you'realso affecting something that we may not think very much about, which is thebrittleness of the coffee so if i give a barista a coffee that i think tastespretty good on the cupping table but it's slightly different in brittleness,then when they go to put that through the espresso machine they're going tohave to make a grind adjustment in order to fix what it is that i gave them.
roasting floor and talk to you really quickly.
them and we've begun pulling shots withevery single origin. most single origins in my opinion 7 out of 10, you can doan espresso roast under no need to blend that good, good, good coffee away. talkabout roasting a single origin to an espresso level.
magnifying glass. body, of course ,isenhanced because of the concentration level of the coffee to water, but reallythat acidity can be kind of overpowering for most coffee drinkers. so people slowit down to tame that acidity down. there is, of course, the theory of, or the methodi should say, of a omni-roast and an omni-roast is one roastthat highlights all of the characteristic that that coffee has to offer, hypothetically, and should work in everybrewing device all the time, including espresso. i believe that there are somecoffees that you can highlight in that way and that there are other coffeesthat simply don't work. so all of these hard and fast rules, once again, put themto the test. at the end of the day, if
you're roasting a coffee for espressoand it tastes bad then don't just say, "oh, i really washoping to avoid an omni--or-- i was hoping to adhere to the omni-roast." no, do what tastes good, follow your palate,do it does every single time. we harp on, that is your goal, you want to be happywith your roast at the end of the day.
how are you going to roast that coffee thefirst time for espresso?
still be there as subtle notes in theespresso version of that same coffee.
