How obvious is "the crack"?

[tabularasa]

Hi there, I'm brand new to home roasting.  On roast 3, in fact.

I've read many pages and watched many videos on home roasting in an oven, and most reference the explosive "crack" I should hear.  I also see that Alchemist John says my final bean temperature should be 250-270 F.

My first batch I roasted were beans I bought from a local bulk baking supply shop.  Ironically they were the most expensive beans of my first procurement, but probably the lowest quality.  Huge range in bean sizes, and discarded probably 25% of them due to being cracked or damaged.

I read the Dandelion book about chocolate so I used their method:  1 kg at a time, single layer on a baking tray, oven at 325F, adjust time-only; my oven is convection.  At 10 minutes I mixed the beans.  At 20 minutes my kitchen overwhelmingly smelled of cocoa.  At 23 minutes my kitchen smelled of burning cocoa.  I took the beans out and their surface temperature was 291F with an infrared thermometer, so I'd overshot John's targets.  I tasted a few nibs and even to my novice taste buds they tasted dark - not burned, but overdone.  Notably, they never cracked.  The milk chocolate I made (John's 1:1:1:1 method) has a distinct bitter end to it, probably over roasted.

My second batch was a much more premium bean from a cacao specialty distributor.  I was much more cautious.  At 6 minutes I stirred, and at 12 minutes I stirred again.  My kitchen smelled of cocoa.  The surface temperature was 265 F after only 12 minutes.  I tasted a nib and they were pleasant but a touch acidic and raw tasting still, so I did another 2.5 minutes and then pulled them.  Total of 14.5 minutes.  No cracks heard.

My third batch was the same premium bean as above.  Six minutes stir, 6 minutes stir, 3 minutes stir, 3 minutes stir, total of 18 minutes.  Again, no crack.  End temperature was 279F.

Why am I hitting the temperature goals and not ever getting the all-important crack sound?  Or, is the cracking even that important?  Why should these beans hit the temperature target in only 12 minutes when most guides say it will take 15-25?

[Sebastian]

One of the issues you'll run into is the tremendous amount of anecdotal 'evidence' presented as fact. I imagine it's brutally frustrating for someone to try to enter this space and make heads/tails of it. You'll find that good meaning people will provide conflicting and incorrect information all the time - not out of malice - but simply because they are attempting to extrapolate what they believe is happening in their localized experience to something contextually broader. It's a little bit like the early tribesmen who'd beat their drums and found that the next day it rained - so concluded that beating their drums summoned the rain. Sometimes it works, sometimes it doesn't. Correlation does not equal causation.

I'm going to suggest to you that the concept of listening to the sounds of beans is perhaps the most imprecise way to go about this possible. It's utter nonsense I also see quit a bit of thermal gymnastics attempted to develop a magical 'roast profile' by changing the time/temp settings on your oven every 13 seconds. For most users - all that's doing is giving you the impression of control - it's not really (usually) doing anything.

The real answer is - it's too complicated to cover in detail in a forum post. If I were you, assuming you're a hobbyist - I'd focus on getting good beans (bean quality is THE single largest driver of quality here - so I'd spend my time digging into what that means, how to assess it, and who to procured said beans from. If you don't start with good beans - you'll never make a good chocolate. I'm also going to suggest that you spend some time thinking deeply about what the purpose of roast is - what big changes are happening to the composition of your beans - and then how to measure it. I'm not talking PhD level biochemistry here - but - big picture, what changes are occurring (it's simpler than you might think) - and once you land that, it'll become fairly obvious how to measure and manage your roasting with precision - vs this notion of anecdotal smells and sounds. Also - while the idea of a bean temp IS important - the surface temp of the bean unfortuatnely isn't really going to tell you much. Most of the nib isn't at the surface What's much more important is the internal temperature - but even that's not what is really important. It's not a bad thing to track and use as a process control, but ultimately, while the internal temp is correlated to what's important - it's not the thing you measure to know if you've successfully roasted or not...

I also realise I'm not giving you the easy answer 8) There's a couple of reasons for that, but i'll be interested in seeing what thought processes this spawns here (or doesn't)...

SJ

[tabularasa]

Thanks Sebastian. In fact, I had similar thoughts in my planning of this new endeavor. When I purchased my cocoa beans I resisted the temptation to buy 1 kg of this and 1 kg of that to try different things. Instead I bought 20 kg of one bean so that I can experiment with it. Roast it darker, roast it lighter, roast faster/slower, make multiple batches of different percentages etc. I figure that if I have many beans I will struggle to know when I'm improving it, but if I have one bean I can work with it to figure out what to do.

I've done two roasts with this bean as I said. I can do another roast at 20 minutes, another at 22 minutes etc, and see where it tastes best. I'm sure that's what you're implying by asking "what's the purpose of roasting" (obviously the answer is: to make it taste good).

However, I'd still keep my question open to the group. If someone asks "how do you cook a steak" then surely "any way that tastes good" is accurate, but it's also not entirely helpful. Rather than leave them to experiment with boiling vs. deep frying vs. grilling, a few basics tips might expedite the process, no?

[Sebastian]

I like your thinking!

Re: the purpose of roasting. From a physio-chemical perspective - i'd argue it's not to make it taste good (that may be one of the results - a potential outcome, but that's not what your oven is doing. Your oven has no flavor receptors...and doesn't care if you burn it or not..). Think more about what your roaster (oven, grill, etc) is doing. What's the macro (non-thermal) change that's occurring during this process?

[mark]

Hi tabularasa

yeah that "first crack" is a key milestone when roasting coffee beans and it appears somebody thought it might also be applicable to cacao roasting. As Sebastian says, it's not. Some of the beans I roast crack sometimes, others never crack. So best to ignore that one.

A few years ago John did a whole series of "Ask the Alchemist" blog posts on roasting. I feel like many of your questions may well be answered by the material there. I learnt a lot from that series of posts and my roasting (and chocolate!) improved substantially based on my new knowledge. The series starts around ATA 190, here's one of the first ones: chocolatealchemy.com/blog/2017/2/9/ask-the-alchemist-194 . Be sure to look at the ones around 200, some really good info there.