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

Well, I don't know who decides on the precise naming conventions, but here is my undertake it:

Tipping
The phrase “tipping” almost certainly describes the phenomenon where the “tip” of the bean burns black. That produces sense if you ask me, at least.

How exactly to “spot” Tipping

Tipping happens once the beans experience any temperature excessive for the bean's heat-transfer coefficient. i.e., there is so much energy (heat) around a particular the main bean that the bean cannot absorb/conduct/disperse the vitality fast enough. The sole choice left is to burn in that area.

An analogy can be found in virtually any kind of meat grilling. A simple lamb chop on the grill has tipping around the edges coffee roasting business. That is caused by a lot of heat at any one time, causing the meat to char instead of cook. This is often what goes on to the beans: there is a lot of heat for the bean to use up, therefore it burns.

What can cause Tipping?

So, when does tipping occur? Truth is that people don't know exactly. This is above tells us so it could happen whenever you want, whenever the temperature is excessive during the roast. It could happen as a result of excessive a charging temperature (the starting temp), excessive a slam during roasting…a lot of heat anywhere!

The following question is whether this really is caused by convection or conduction heat? Put simply: may be the drum too hot or may be the air too hot? The solution is: either. Tipping is really a factor of the beans, not the environment, the roaster, the drum, or air temperature. The fact is that the beans cannot handle it.

Look at the image below:

Tipping
Photo Source: www.sciencedirect.com

The colours show the difference in temperatures inside the beans. It is clear from the image that, if anything should burn, it would be the tips of the beans! But this changes with respect 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 effect of Tipping you roast?

So, is tipping a poor thing? That's a question 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 have tipping, then surely tipping is not just a bad thing! May be the “tipping” on the lamb chops a poor 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, nonetheless it still tastes great!  The chances of tipping affecting your roast to the stage of getting to dump everything is extremely slim.  Chances are that the chosen profile or roast degree is way off, and that tipping is a tiny the main problem.

Scorching
So, if tipping is really a burnt spot on the tip of a bean, then what's scorching? In my experience, scorching is bad practice. Not necessarily a poor tasting bad practice, but one which 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. The same as 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 should not need to scorch the beans to attain 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:

Scorching
Photo Source: www.perfectdailygrind.com

Cratering
There will be a lot of confusion between craters and tipping. Both are VERY far apart. Cratering happens near or into second crack where the pressure inside the beans is released at this kind of higher rate that the bean's surface cannot handle the release. That is per definition “second crack”, but in case of cratering, the second crack was brought on so much so it affects the structural integrity of the bean and literally blows an item off once the bean releases the built-up gasses inside the bean.

Crating
Photo Source: www.fullcoffeeroast.com

What is the answer?
If you decide that tipping, scorching, or cratering is the cause of 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 must also help, in addition to increasing the batch size and drum speed.  The best is always to roast longer and gentler to allow your beans enough time to absorb and distribute the vitality that you are trying to force into them.

Scorching: Reduce your charge temp and increase your drum speed.  The less time the bean spends on the side of the drum, the less scorching you'll have. Try to maximise your convection heat and minimize your conduction heat, i.e., transfer your energy by way of hot air instead of a warm drum.

Cratering: Increase enough time from first to second crack and take a gentler approach will help to prevent cratering.  Dial back in your gas pressure when you reach first crack and allow 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 dependence on 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. Click the link to see this type of module.