HELP! What’s happening to my beans?

There seems to be a massive misconception between tipping, scorching, blowing, and burning.. Part of the problem is there’s no naming convention – does “roaster” reference the individual or the machine; is “dropping” taking the beans out or putting them to the drum? Is “tipping” and “scorching” the same thing and how can we spot the difference?

Well, I don’t know who decides on the exact naming conventions, but here’s my take on it:

The phrase “tipping” probably identifies the phenomenon where in actuality the “tip” of the bean burns black. That makes sense to me, at least.

How to “spot” Tipping

Tipping happens once the beans experience any temperature too high for the bean’s heat-transfer coefficient. i.e., there’s so much energy (heat) around a particular the main bean that the bean cannot absorb/conduct/disperse the power fast enough. The only real choice left would be to burn for the reason that area.

An analogy is found in any form of meat grilling. A straightforward lamb chop on the grill has tipping around the edges coffee bean roaster machine. That is caused by an excessive amount of heat at any one time, evoking the meat to char in place of cook. This is often what goes on to the beans: there’s an excessive amount of heat for the bean to take up, so it burns.

What can cause Tipping?

So, when does tipping occur? Truth is that we don’t know exactly. The meaning above tells us so it sometimes happens whenever you want, whenever the temperature is too high during the roast. It sometimes happens because of too high a charging temperature (the starting temp), too high a slam during roasting…an excessive amount of heat anywhere!

The next question is whether this really is caused by convection or conduction heat? In other words: may be the drum too hot or may be the air too hot? The answer is: either. Tipping is really a factor of the beans, not the environment, the roaster, the drum, or air temperature. Truth be told that the beans cannot handle it.

Consider the image below:

Photo Source: www.sciencedirect.com

The colours show the difference in temperatures within the beans. It is clear from the image that, if anything should burn, it is the tips of the beans! But this changes with regards to the bean: try finding tipping on peaberries. Because the peaberries are round and has very little distinct “tip”, the chances of tipping happening are much smaller in peaberries.

What is the effectation of Tipping you roast?

So, is tipping a bad thing? That is a concern only the drinker can answer. Allow me, as I cannot stress this enough:


In other words, if the coffee tastes bad, then tipping is bad. If your coffee tastes good but you’ve tipping, then surely tipping is not just a bad thing! Could be the “tipping” on the lamb chops a bad thing? No, most of us love a little char-grilling on our chops. But surely this really is per definition a burnt chop? Well, possibly so, but it still tastes great!  The chances of tipping affecting your roast to the stage of experiencing to dump it all is extremely slim.  Chances are that your chosen profile or roast degree is way off, and that tipping is just a tiny the main problem.

So, if tipping is really a burnt spot on the tip of a bean, then what is scorching? If you ask me, scorching is bad practice. Definitely not a bad tasting bad practice, but the one that points to inexperience on the side of the roast master.

Scorching happens once the bean touches a floor that is too hot for the thermal conductivity of the bean. Just like for tipping, but almost exclusively caused by conduction heat. In layman’s terms: your drum was too hot! Here is another cooler charge temperature or decrease the ramp-time of one’s profile to negate any scorching. You ought not need to scorch the beans to accomplish your preferred roasting profile.

Scorching is different from tipping in so it typically presents on the flat side of the bean. It is really a larger spot that is burnt black.

Here’s what scorching seems like:

Photo Source: www.perfectdailygrind.com

There will be a lot of confusion between craters and tipping. The 2 are VERY far apart. Cratering happens near or into second crack where in actuality the pressure within the beans is released at this type of high rate that the bean’s surface cannot handle the release. That is per definition “second crack”, but in the case of cratering, the 2nd crack was triggered so much so it affects the structural integrity of the bean and literally blows a bit off once the bean releases the built-up gasses within the bean.

Photo Source: www.fullcoffeeroast.com

What is the solution?
If you decide that tipping, scorching, or cratering is the cause of any unwanted flavours in your bean, here’s what to do:

Tipping: Lessen your charge temp and execute a slower, gentler roast.  Increasing your convection heat should also help, as well as increasing the batch size and drum speed.  The very best is always to roast longer and gentler to allow your beans enough time to absorb and distribute the power that you are attempting to force into them.

Scorching: Lessen your charge temp and boost your drum speed.  The less time the bean spends on the side of the drum, the less scorching you’ll have. Try to maximize your convection heat and minimize your conduction heat, i.e., transfer your time through heat in place of a warm drum.

Cratering: Increase the full time from first to second crack and have a gentler approach will assist you to prevent cratering.  Dial back on your gas pressure when you reach first crack and allow the beans carry themselves into second crack.   In the event that you force more and more energy to the batch, it stands to reason that “something’s gotta give&rdquo ;.In cases like this, the entire bean is splintering apart because of one’s need for burnt coffee!

The Genio Academy, along with Shaun Aupiais from We Roast Coffee produced a brand-new online Coffee Roasting 101 course on our Genio Hub, available to any or all Genio customers, where he discusses common roasting defects in depth. Go through the link to see this type of module.

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