There seems to become a massive misconception between tipping, scorching, blowing, and burning.. Part of the problem is there’s no naming convention – does “roaster” refer to the person or the equipment; is “dropping” taking the beans out or putting them in to the drum? Is “tipping” and “scorching” the same and just how do we spot the difference?
Well, I don’t know who decides on the actual naming conventions, but here is my take on it:
The phrase “tipping” almost certainly describes the phenomenon where in fact the “tip” of the bean burns black. That produces sense in my experience, at least.
How exactly to “spot” Tipping
Tipping happens once the beans experience any temperature too much for the bean’s heat-transfer coefficient. i.e., there’s so much energy (heat) around a certain area of the bean that the bean cannot absorb/conduct/disperse the power fast enough. The only choice left is to burn for the reason that area.
An analogy is found in just about any form of meat grilling. A straightforward lamb chop on the grill has tipping round the edges. This really is brought on by too much heat at any one time, inducing the meat to char in place of cook. This really is what are the results to the beans: there’s too much heat for the bean to occupy, so that it burns.
What causes Tipping?
So, when does tipping occur? The fact is that we don’t know exactly. The definition above tells us that it can occur anytime, whenever the temperature is too much throughout the roast. It can occur as a result of too much a receiving temperature (the starting temp), too much a slam during roasting…too much heat anywhere!
The following question is whether that is brought on by convection or conduction heat? Put simply: may be the drum too hot or may be the air too hot? The answer is: either. Tipping is just a factor of the beans, not the environmental surroundings, the roaster, the drum, or air temperature. The fact is that the coffee bean 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 respect to the bean: try finding tipping on peaberries. As the peaberries are round and has almost no distinct “tip”, the odds of tipping happening are much smaller in peaberries.
What’s the aftereffect of Tipping you roast?
So, is tipping a poor thing? That is a concern only the drinker can answer. Allow me, as I cannot stress this enough:
TASTE YOUR COFFEE!
Put simply, if the coffee tastes bad, then tipping is bad. If your coffee tastes good but you’ve tipping, then surely tipping is not a bad thing! Is the “tipping” on the lamb chops a poor thing? No, all of us love a little char-grilling on our chops. But surely that is per definition a burned chop? Well, possibly so, nonetheless it still tastes great! The odds of tipping affecting your roast to the point of getting to dump all of it is extremely slim. Odds are your chosen profile or roast degree is way off, and that tipping is only a really small area of the problem.
So, if tipping is just a burnt spot on the end of a bean, then what is scorching? In my experience, scorching is bad practice. Not necessarily a poor tasting bad practice, but one which points to inexperience quietly of the roast master.
Scorching happens once the bean touches an area that’s too hot for the thermal conductivity of the bean. Just like for tipping, but almost exclusively brought on by conduction heat coffee roasting business. In layman’s terms: your drum was too hot! Try a cooler charge temperature or decrease the ramp-time of your profile to negate any scorching. You ought not have to scorch the beans to achieve your preferred roasting profile.
Scorching is different from tipping in that it typically presents on the flat side of the bean. It is just a larger spot that’s burnt black.
Here is what scorching seems like:
Photo Source: www.perfectdailygrind.com
There is of confusion between craters and tipping. The 2 are VERY far apart. Cratering happens near or into second crack where in fact the pressure within the beans is released at this kind of high rate that the bean’s surface cannot handle the release. This really is per definition “second crack”, but in the case of cratering, the next crack was induced so much that it affects the structural integrity of the bean and literally blows a piece off once the bean releases the built-up gasses within the bean.
Photo Source: www.fullcoffeeroast.com
What’s the perfect solution is?
If you decide that tipping, scorching, or cratering is the explanation for any unwanted flavours in your bean, here’s what to do:
Tipping: Reduce your charge temp and execute a slower, gentler roast. Increasing your convection heat should also help, along with increasing the batch size and drum speed. The most effective would be to roast longer and gentler allowing your beans enough time to absorb and distribute the power that you want to force into them.
Scorching: Reduce your charge temp and raise your drum speed. The less time the bean spends quietly of the drum, the less scorching you will have. Try to maximise your convection heat and minimize your conduction heat, i.e., transfer your power by means of hot air in place of a hot drum.
Cratering: Increase the full time from first to second crack and have a gentler approach will help to prevent cratering. Dial back on your gas pressure after you reach first crack and allow the beans carry themselves into second crack. In the event that you force more and more energy in to the batch, it stands to reason that “something’s gotta give&rdquo ;.In cases like this, the complete bean is splintering apart because of your dependence on burnt coffee!
The Genio Academy, together with Shaun Aupiais from We Roast Coffee produced a brand-new online Coffee Roasting 101 course on our Genio Hub, available to all Genio customers, where he discusses common roasting defects in depth. Click the link to view this specific module.