Ep #4 – Beyond first Crack

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<Dave> Hi, this is Dave Borton, Mill City Roasters, along with…

<Joe> Joe Marrocco, Cafe Imports.

<Dave> Today we’re looking at beyond first crack, or something to the effect of burning the hell out of the beans. Joe cleaned it up for PG audiences.Beyond first crack. In Roaster School for these last five weeks, we’ve been looking at the different stages of roasting, 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’s All yours, my friend.

<Joe> Sounds good. Thank you, sir. Yes, we are going to talk about what happens after first crack, including second crack and beyond. So often beginning roasters especially, are roasting well beyond first crack into those darker realms of coffee that we call second crack. There are –

<Dave> Dark side.

<Joe> Yes, the dark side. You’ve got to start in the dark side in order to pull yourself back toward the light side at times.  

<Dave>  There you go!

<Joe> So coffee is this really cool product that starts out with so much potential in so many variances.However the vast majority of coffee that is drank around the world is something that I would call nostalgic coffee or that coffee-coffee. The flavor of coffee that is so ubiquitous with all of the coffee that you taste. And the way that that ubiquity happens is through roasting all of the coffees beyond first crack and into or maybe even beyond second crack. So, in other words you can take all of the dynamics that are in these 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 consider coffees to be unique based on where they’re grown, how they’re processed, the variety, the altitude, and that’s why for the most part, you’ll hear Dave and It each that you should never move too far into second crack, because you’re taking all of that lovely characteristic – all of the things you paid a little extra money for – and you’re homogenizing that. You’re burning it out of the coffee.However, there are times and places where roasting a coffee more darkly is appropriate, and as we have said in this program before, roasting is not a moral endeavor.

<Dave> Amen.  

<Joe> It is an aesthetic endeavor. Now, moving into second crack,past second crack, there is a third crack.At third crack, that is where it becomes a moral endeavor.OK, I’m just kidding. We want to make sure that no matter how we’re roasting,that we know our target, we have our target in mind, and we’re able to hit that target. So that’s why today we are going to talk about second crack, we are going to talk about roasting a little bit more dark, because that may be something that you at some point want to do, and you should have the tools in your toolbox to execute that, execute it well, and execute it repeatedly. Dave and I were speaking before this, and even he and I have differing opinions on how to approach second crack, and we’re going to get into some of that, too. So, what happens? OK, so here you drop the coffee in, you have the turning point, it goes through yellow,you go through your development time prior to first crack, development time after first crack, and then all of the compounds that are in the coffee,they continue to go down their domino effect, their chain of reactions to the point where they have dissipated so much, that eventually they leave behind the carbon skeletal frame of the molecules that they once were.Now, within coffee, there are a lot of resources out there that use terminology that I have listed here, and I want you to know that this is actually not what’s happening within coffee, generally.Generally, these three things need very high temperatures, and they’re happening to much more complex molecular structures that are in organic material.Like for instance, dry distillation, carbonization, and well, all of these, happen in places like a volcano or something like that.Usually there needs to be a void of oxygen. Now, there are subtle snippets of these reactions that are taking place in coffee, 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 as you’re moving it forward through the roast.Of course, some of these things can kind of happen, but these are very complex physical things that take place at very high temperatures. So we’re going to focus just on charting, because charring not only speaks to what’s physically happening in the coffee, but it’s also speaking to the flavor that you get out of the coffee and the visual cues that you get within the coffee, so it’s a really good term. And what does charring mean? Well, charring means that you are getting flavors of burning. If You take a steak, for instance, and you swear 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 of charring, and that adds to the complexity of that piece of meat. It adds to the flavor. You go through the Maillard Reaction on that piece of meat, and then past that, you start to burn up those compounds that are on the exterior part of that piece of meat, and you get a little bit of carbonyl flavor. Carbon Flavors, 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 it is, they’re pretty much the same – coffee.But they add to the complexity of that coffee. So there are different ways that you can go about approaching that charring, and whether or not you want to preserve the flavors that were there prior to the charring, like you would on a medium rare steak, or whether you want the coffee itself all the way through to taste more on the charred side. So, why would you ever want to do that?Well, if you get that coffee that is defective, or there’s something it’s getting too old or there’s something about the coffee that is negative, you can actually cook those flavors out by changing those compounds that are making the negative flavor into flavors of charring. Some people prefer darker roasts of coffee, because they actually enjoy this flavor in a big way. And so they prefer dark roast because, charring is a flavor that we here refer to as robust or strong or intense. It’s One unique flavor that can be overpowering in the cup.

<Dave> and Joe?  

<Joe>Yes, sir.  

<Dave> A lot of our customers that buy the smaller the time, and they’re working with customers that are asking for those oily beans.

<Joe> Yes.

<Dave> And they say, “Well how do you manage that?” and I say, “You provide the customer what they want,but you provide them options. That customer isn’t wrong. They’re going off nostalgia, or they’re backing up and they’re familiar with that charred, roasted flavor and they think that’s the best that coffee can do.So I suggest to them that they use them as a dialogue opportunity, because that customers not wrong, that customer is willing to pay $14 for a full pound of that roasted coffee that’s a bit charred–give them some opportunity, use that for an education.

<Joe> Absolutely, yes, so if you want that more charred flavor, there are a couple of ways to go about it.One, if you go through first crack and you continue to move very quickly into second crack, you can roast the outside of that coffee–those outside layers will start to get that cherry flavor, but the interior of that coffee maybe kind of protected because it’s not moving quite at the same speed as the outside. So you hit that second crack pretty hard and then you drop it as you move into that second crack. And you can preserve some of the natural flavor of the coffee, that you developed into the coffee, while at the same time adding that char flavor to the outside. So, it would be more like your medium to medium-rare steak approach to sharing the coffee, or if you slow it down as you’re moving into second crack–by slowing it down you can kind of breakdown some of the unique characteristics of a coffee, almost to the point where you can even bake if you do this more exaggerated, and then bring it into second crack nice and slowly and then you 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 the exact same place every time because that last moment of landing the plane is very volatile. Roasting coffee into second crack is very similar. If you move very quickly,it’s very hard to hit the exact same target 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. If I drop a coffee a minute after first crack and then a minute and 10 seconds after first crack, the difference is going to be a lot more subtle.However, the same coffee doing that in second 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 go further 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 the bean 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 the pressure builds up so much so that the the coffee seed bursts open and allows all of that gas to release. However, once it has released that gas, now the bean is more porous and open, and anymore gases that are being built up in the coffee are starting to gas off very quickly.However, as we move through second crack the actual cellulose structure of the seed itself begins to decompose. In that decomposition adds for a lot more gas,especially carbon dioxide to start building up on the inside of that seed.And with that structural integrity breaking down, it doesn’t really need to swell the seed anymore. It’s so brittle that’ll just start cracking and breaking down the actual cell structure itself. If you move quickly into second crack, you’ll see those little pucks fly off, we call that chipping. Those Little disks that pop off, they’ll blast off the side of the coffee and leave a little crater, that is something that tells us we’re moving too quickly and much more violently or volatile-through that phase of second cracked. So slow it down, if you see that. That is actually considered a roast defect by the SCAA and others. So slow it down, keep it chill.

<Dave> Too much heat, too fast.

<Joe> That’s right, especially too much convective heat will do that.

<Dave> Our guys that are on poppers at home will often see those divots, or chipping.

<Joe> Yes.

<Dave> Right out of the side of the bean, those black circulars.

<Joe> And Generally if you’re roasting on a popper you’re using a lot of air, and that air,that convective heat, is what is doing that. You can modulate your poppers. I’m Sure you guys know this from several threads on home barista, to where you have a dimmer switch for the power that your popper has. You can also gently shake it at lower heat so that it doesn’t have quite so much air, but you’re still keeping it aloft. There are a few tricks that you can do to kind of slow down that second crack.

<Dave> Sure.

<Joe> Okay, so oil.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 seed become more open, which is through the degradation of cellulose and also through the swelling of the seed that took place during first crack and beyond,you are allowing for those large fat molecules that have now broken free from where they normally had been. 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 oxygenation very 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 nostalgic flavors that we think of in coffee are actually also stale flavors in coffee. So I do highly recommend that if you are doing dark roast, that you use those dark roasts very quickly. If you don’t, the oil on the outside becomes rancid. Some Studies shown that rancidity of oil in coffee takes place within about 30 seconds. Of course that’s unavoidable. If you have the coffee out on the cooling tray it’s going to cook with in that amount of time. Rancidity is simply the oxygenation of the fat, of the oil itself,which can cause off flavors. So I do recommend that if you are going to go dark try to get the the flavor of charring on to the coffee in a way that still preserves some of the flavor within the seed, while not allowing a bunch of oil to come pouring out. So Hitting the first part of second crack to where you are getting a little bit of that charring can bridge the gap to your drinkers that are looking for a more nostalgic 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.

<Dave> Joe, can we talk about this charring for a moment?

<Joe> Sure.

<Dave> Relative to individual origins–excuse me–I notice with my Brazil’s I’m very apt to get into trouble here,with that charred flavor in that cup, is that because that’s a softer bean? Is any of this elevation or density-dependent?

<Joe> Definitely. So I Have a theory, and I want to state very clearly that this is a theory. And This is actually the first time I’m Debuting this theory publicly. Ok, so I–got the microphone?–

<Dave> Listen closely.

<Joe> So a lot of your Brazilian coffees are naturally processed,which means that you have pulled the cherry off the tree and you’re drying that cherry out, my theory–and I hesitate to state this yet but I’m going to state it anyway–I’ve spoken to enough people–

<Dave> Drum roll.

<Joe> That I think that this may actually be true.My theory is that while that seed is inits husk, the cherry skin, and it’s sitting in its juices and then slowly drying down in the warm sun for 4, 6 weeks at a time, that the seed inside of that cherry is actually beginning the germination process. So it’s beginning the malting process. And what malting means is that all of those compounds that have been stored up in the cellular structure of that seed are beginning to be unlocked, and they’re beginning to become more soluble. Which of course, when we roast 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 the case of malting, like if for instance barley and wheat for beer, you allow the seed’s germination process to breakdown those heavy starches and begin that process of making that product soluble.So, my theory is that with a naturally processed coffee we’re already a little bit farther along in that molecular chain of breaking down those compounds. And so since we’re further along there, once we get the first crack we’re actually further along in the roasting process than we think we are.And so instead of thinking about oh I Should drop this a minute after first crack, because we are further along the chain of development.We’re still trying to abide by these old hierarchical rules that have been dictated to us, that we should go a minute and a half to two minutes after first crack, and so we’re already over roasting the coffee when we should have listened to the cupping table 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 things down, and to roasted a little lighter. Know That second crack may come a time where the coffee tastes more dark already.

<Dave> So anybody that’s working on their thesis proposal in organic chemistry let’s say, could take Joe Morocco’s Proposed–would be a hypothesis at this point?

<Joe> This is a hypothesis.

<Dave> Ok, take the hypothesis and do your PhD studies on this, because this stuff is all untested.

<Joe> Yes.

<Dave> I think i’ve heard Joe Talk time and time again,”yeah we know some things about coffee,but one of the fascinating things about coffee is there so much yet to be explored.”

<Joe> That’s right, and I will be testing this theory, just for the record. I just don’t know when yet–whenever I get the time.

<Dave> Very good.

<Joe> Do we have any questions?

<Dave> Just a minute, we’re waking up Nick here…he’s moving. Questions will come, shortly.

<Joe> We have a little time delay.

<Nick> Pyrolysis, am I saying that correctly?

<Joe> Pyrolysis, yes.

<Dave> Pyrolysis, it means fire.I know that much of it. That’s all I Know.

<Nick> Greek/ Latin base.

<Nick> Here is the question: Please ask Joe about that? So I’m not exactly sure where to go with that.

<Dave> So I’m going to defer to somebody that knows something about science.I majored in business.

<Joe> So pyrolysis is, obviously pyro is fire, and this part was referring to a process of what is happening within fire. When there is no oxygen present and you have very high temperatures, you’re still breaking down molecules, basically, and so it is an oxygen-free high temp breakage of molecule from whatever state that molecule was, in down to its basic carbon element. And so, there is potentially some of this that is happening within the coffee seed but there’s no way for me to say, in this cell,on this molecule, there was no oxygen present. On this one over here there was oxygen present. And so, we had two different types of breakdown of these two molecules and so therefore we have two different flavors that were created due to that. It doesn’t matter, because at the end of the day you’re breaking it down to more carbon base regardless of whether there’s oxygen or whether there is no oxygen present. So that’s why for us to be more exact we actually have to be less exact within the general sense of roasting coffee.These are extremely specific reactions that take place under very specific types of environments, and so we don’t know exactly.

<Dave> Hence, you call it charring, rather go into all the organic chemistry. Joe, I had a question left over from other sessions.

<Joe> Yes, please.

<Dave> Here we got 11% water by volume at the end of drying were down to about 1%–

<Joe> 1.5% to 1%, something like that, yeah.

<Dave> Water drives so much of the chemical compound changes in this dry. What is driving the chemical changes from end of drying on?

<Joe> So here you don’t really have chemical changes that are taking place. From this point you have the absorption of heat, it’s pulling heat into the sea,so that the chemical changes will take place so this is endothermic heating, or the heating of absorption, whereas this is exothermic heating, or the creation of new energy through chemical breakdown.And every time you have a molecule break,there’s a little snippet of energy that is given off and there’s also a snippet 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, whether it’s conductive or convective energy,that energy is hitting a molecule at a temperature that is reactionary for that molecule, that molecule breaks. That Breakage does not happen prior to yellow.And when it does happen we refer to those chemical breakdown processes as the maillard reaction and caramelization primarily, but there are also a lot of other reactions that are taking place.

<Dave> Very good. There is Part B to that question but I don’t remember what it was in my head.

<Joe> Ok cool, any other questions?

<Dave> Well it’s going to be a wrap? That was a quick one.What other– Joe, one question came up,would you show your way to take your rate of rise into second crack?

<Joe> Sure.

<Dave> From a production roast standpoint.

<Joe> Absolutely. I’ll show you two ways. I’ll call them Dave’s way and Joe’s way. Also, known as the right way and the wrong way.

<Dave> Mine is just a hypothesis.

<Joe> So also know that mine is informed by production roasting, ok, and so when you’re a production roaster you’re approaching things in a different manner than if you are a home roaster and you’re trying to do something experimental and like one off, one time, and trying different coffees to see how that particular coffee tastes the best at a dark roast. If you want to do that way, 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 muchafter first crack, what Dave recommendsthat you do is don’t worry aboutdevelopment time here, because all ofthese subtle nuances that you want toget out of the coffee– these are nuancesby the way all– of these subtle flavornuances 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 momentumthat you would have dropped the coffeewithout it going to second crack. Is that correct?

<Dave> That’s correct.The first crack gas off, approaching first crack, I do not diminish the heat and so that rate of rise  just runs through there without the typical divot that we see when those gases come off the bean–during first crack.

<Joe> And my recommendation is as you’re going up through your rate of rise it normally looks a little bit like this Where you do have a divot. Obviously don’t want the flick,ok, you do have the divot and then it comes down,and then you should just continue to kind 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 get further into second crack, as long as you’re able to control that and hit the same mark every single time. If your production roaster it’s very important that you’re hitting the same mark every time. There’s not something called a better 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 roast is that you did not hit that mark.

<Dave>And one of the reasons i teach this, this is the tough dance.

<Joe> It’s a very tough dance.

<Dave> Particularly as Joe says you want to hit that mark, and this just say it’s 11:41, time, after time, after time because you’re doing hundreds of pounds.Most of the fellows, the ladies, that come in here are relatively new to coffee roasting and I’m not sure i want to give them this dance to learn, because they indeed will have customers that are going to want that second crack.

<Joe> Yep. And at the end of the day we are roasting for flavor. And what does that mean? That means we’re roasting the coffee so that when we give it to a barista, or to ourselves if we’re a home roaster, whoever it is that’s going to brew that coffee,we want them to have a successful extraction which leads to a successful flavor experience. So when you start getting deeper in this roast you’re affecting not only flavor, but you’re also affecting something that we may not think very much about, which is the brittleness of the coffee so if i give a barista a coffee that I think tastes pretty 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 to have to make a grind adjustment in order to fix what it is that i gave them.

<Dave> You’re going to come right out to the roasting floor and talk to you really quickly.

<Joe> And so if i’m doing multiple roasts and make multiple subtle differences or variations on where i’m dropping, and how i’m dropping, and these coffees all have different brittle intensities then my braces can be very frustrated because they’re going to have to continually make adjustments. If you have a very consistent roasting program the brittleness of each type of coffee that you roast should be very consistent and the barista that should be set up to where they’re not making and finagling a bunch of adjustments to fix where the coffee is. And that’s a big deal.Joe, a second question we offer eight to ten single origins here, and we’ll cut them and we’ve begun pulling shots with every single origin. Most single origins in my opinion 7 out of 10, you can do an espresso roast under no need to blend that good, good, good coffee away. Talk About roasting a single origin to an espresso level.

<Joe> Yeah, so there are different rules of thumb on how you should do this.The general way that most companies roast for espresso is they go a little bit more slow through first crack and after first crack, what they call development, so that you can kind of tame down the acidity and bring to light a little bit more of the sweetness because when you put that coffee through an espresso machine it’s like taking a magnifying glass and shining only the acidity through the magnifying glass. Body, of course ,is enhanced because of the concentration level of the coffee to water, but really that acidity can be kind of overpowering for most coffee drinkers. So people slow it down to tame that acidity down. There Is, of course, the theory of, or the method should say, of aomni-roast and an omni-roast is one roast that highlights all of the characteristic that that coffee has to offer, hypothetically, and should work in every brewing device all the time, including espresso. I believe that there are some coffees that you can highlight in that way and that there are other coffees that simply don’t work. So all of these hard and fast rules, once again, put them to the test. At the end of the day, if you’re roasting a coffee for espresso and it tastes bad then don’t just say, “oh, I really was hoping 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 happy with your roast at the end of the day.

<Dave> Happy cups.

<Joe> Happy cups, happy cups.

<Dave> Joe, I’m gonnagive you a new single origin Ethiopianit’s a washed yirgacheffe and you’re going to want to roast that the first time not for evaluation,not for cupping, not for pour over.You’re going to run them through yourswiss cremina at home, your espressomachine.How are you going to roast that coffee thefirst time for espresso?

<Joe> My personal preference, if I’m drinking this coffee,if I’m drinking it for regular consumption through a regular brewer I Would use something generically called,more of a city plus kind of roast and if I’m doing it for espresso it’s going to be more of a full city to full city plus.

<Dave> Okay , full city plus is right on the cusp,we’re five cracks into second crack and then drop it.

<Joe> I would be right before a second crack, develop a little bit more of the chocolatey characteristic of that coffee,tame down the acidity, and I think that’s how you control those subtle notes that you have in a cup of that coffee to still be there as subtle notes in the espresso version of that same coffee.

<Dave> Nick, this is going to be a wrap unless you’ve got some more questions for us.

<Nick> Nope.

<Dave> Thanks very much Joe Marrocco for your continuing presence with us,the superb information presented in a digestible way that helps me improve my roast.

<Joe> Good.

<Dave> I appreciate it. So to all of the you out there we say thanks for looking in we’ll see you next month.

<All> Bye.



Addicted to coffee at a young age, Nick has turned his caffeinated attention towards coffee roasting education. Behind the scenes, Nick produces, directs, and edits all video series for Mill City Roasters.