Most of us amateur roasters buy beans at different times and different varietals from different farms and suppliers. Some of the inconsistencies we face when buying beans, even from the same farm, is that the farm region has different environmental seasonal changes each year, different aged plants, usually a mix of varietals, varying processing environments during the harvest season, and plants at different altitudes. All these varying from one bag and shipment to the next.

Then our roasters have consistency issues like thermocouples and placement, temperature variations during the roast, environment temp, air-flow, drum speed, and roast batch size variations. All this besides the different types of roasters and consistency in roasting techniques and profiles. I assume that these all vary somewhat in the way from batch to batch.

In the brewing process, people have differences in brew methods, such as V60, Chemex, French press, AeroPress, Moka pot, vac pot siphon, drip, etc. All have different tecniques producing a different cup.

Then there is different grinders, grind size, water temperature, grounds to H2O ratio, extraction rates, and other consistency issues.

I've concluded that no batch of beans is the same, following the roasting profile is not exactly the same every time, no roaster the same, no grinder grinds the same, no water the same, no consistency in brewing, grinding and extraction, and our taste buds are not the same every day.

We evaluate the coffee by our cupping taste preferences differently than how others might grind, brew and drink.

After considering all these inconsistencies with beans, roasting, brewing and taste subjectivity, I'm of the opinion the art and science of roasting have too many variables from one batch to the next for us amateurs to deal with a different profile each time we roast based on own subjective cupping results.

After roasting several years and having many people doing blind cupping for me scores of times, I have found that EVEN the same roasted batch of beans will give a wide range of results from different people. Especially considering no two people brew exactly with the same equipment and procedure. Not to even mention the subjectivity of what each person might like.

I have given people 2 separate bags of coffee from the same roast batch and they gave me different cupping results for each bag! Do we think that all these inconsistencies and the way we cup our roasts will produce consistent results with the various people we supply coffee to?

I know that many experts might disagree, but I think some amateurs are fooling themselves that every batch of beans needs a different profile to get excellent results or maybe even near-perfect results. Besides how many will brew the coffee the same way it was tested? I think the most important thing is good beans to start with then work on a profile that works best for your roaster validated by you and your freinds.

As an amateur roaster, I started by studying scores of award-winning roasting profiles and found there is a common thread to most of their profiles. Dry time (200F - 300F) about 4 minutes, Maillard time to first crack about 4+ minutes, development time is more or less around 3 minutes. In reading Scott Reo's material on roasting he states something to the effect that he hasn't seen a profile of an award-winning roast that didn't have the development time between 20% - 25%.

So just like my washing machine, dryer and dishwasher that have many different cycle options, I always use the "normal cycle" when using them. Same for roasting coffee! I use the same profile for all my beans (http://www.bobbooks.net/ROR.htm). I'm not suggesting that this is the best profile for your roasting, but it sure has been a winner for me.

The only basic thing I vary with the roasting profile is the development time to get different roasts from light to city+ and the drying time because I buy my beans directly from a farm in Nicaragua where they only harvest during last of December to spring, so if my beans are getting older I might shorten the drying time up a little.

About 90% of my roasts use the same profile listed here are pulled at the beginning of the second crack. I always have excellent results from all who taste my coffee.

That's the fun of being an amateur roaster! Trying different beans, roasting profiles, and brewing methods to get coffee that "tastes exceptional" to you and your friends.

Take my spin for what it's worth as I'm only a novice roaster, still learning with every roast and a lot more to learn! I would appreciate your comments positive or negative.

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Bob Books

by Scott Rao August 12, 2014

Scott Rao has been in the coffee business for 20 years as a cafe owner, roaster, author, and consultant. Scott has written four books, including "The Professional Barista's Handbook" and most recently "The Coffee Roaster's Companion." When he's not writing, Scott is usually training roasters or sipping Sencha tea in the corner of a cafe. You can contact Scott or view his books at www.scottrao.com.

Over the past decade as a consultant, I've had the opportunity to cup thousands of roast batches from more than two dozen machines, and to compare those batches' roast data to their cupping results. Upon focusing on only the most stellar, memorable batches, a few patterns became clear: One was that first crack* began at between 75%-80% in all the great batches. Put another way, "development time" was between 20%-25% of total roast time.

For six years I've been waiting to taste a delicious, sweet, well-developed coffee from a roast batch in which first crack began outside of that range. I have yet to find it. This ideal "development-time ratio" (DTR) has been valid for all roast degrees and roast times I've experienced. To be fair, I don't often cup roasts dropped well before the end of first crack or well after the onset of second crack, so I won't assume the ratio is valid for those roast levels.

Roasters have historically focused on "development time" (defined as the time from the onset of first crack until the end of a roast) and discussed it in isolation. For example, roasters have frequently asked me to taste a coffee and then said "development time was three minutes." To me, that piece of roast data is relatively meaningless out of the context of the total roast time.

I recommend roasters focus on the DTR rather than nominal development time. When roasters manipulate development time without considering it in the context of the total roast time, they often create baked flavors and destroy sweetness.

I mark the beginning of first crack as the moment I hear more than one or two isolated cracks. If you measure the beginning of first crack differently, your results may differ.

Scott Rao