EricS wrote:
I'm struggling the produce the same result for the blend that I find really nice. I am using the same ratio's: - 50% Guatemala (Alliance beans) - 25% PNG (probably Alliance as well) - 25% Peru CdS For the blend that I really like, both the Guatemala and the PNG has been taken to some 5-10 seconds after crack. I didn't roast up to that level last week as they start to oil by the first week. The cup that I've got from that blend was well rounded, medium bodied and I probably could even taste some chocolate notes and the balance of acidity was just right. Didn't get that from last week's roast as we've decided to avoid second crack. Any ideas on whether I should roast it past second crack again? Is the oil-ing of beans a real concern? Somewhat in a dilemma now on what I want to do this week.
Eric. The crack, whether it is first, second, etc. is just an indicator only - a reference point or marker, but in reality it will not mean that much as there are typically, say 12 - 17 minutes involved in a batch and the entire period needs to be considered as a whole, a.k.a. the profile. I know you are seeking advice and recommendations, but the reality is you will need to roast plenty more batches, keep detailed notes and it's critically important to review and evaluate the variables and parameters used against the results and outcome in the cup - and how this changes throughout the days/weeks following a batch. There is no silver bullet, iron-clad, definitive answer to your question as others will be roasting on apparatus that whilst might be of similar design, type or method, will most likely be actually quite different. The roasting device and how it is operated (including external cooling) will affect the cup more so that the beans used in your current early stages of roasting practice. The only thing different beans will offer you is how they are responding (or tolerating) your roast technique (or profile) and that is assuming a VERY important factor - you can repeat each roast perfectly in terms of temp and time. Oil is the essence of coffee flavor. You can google up plenty of comments about whether oil on the surface of a bean is a good or bad thing and of course it really depends upon the intention of the roast - how it is to be extracted or brewed. Roasters (and I'm referring to commercial) have varying opinions on when oil should start to appear on the surface of a roasted bean - if at all. Roasting, like golf, is an acquired skill developed by practice and being able to learn, adapt and evolve. Roast more coffee, focus on consistency, note everything you do differently and mark it as either a positive or negative improvement, feed it back into your loop so that you can understand why your roaster and technique produce the cup you taste. It sounds like a daunting effort (but it's essentially about elapsed time and PATIENCE), however, once you have this understanding things will fall into place quite easily and you can start to exploit the diversity of bean selection and blending. Put aside the blending for the moment. Grab an easy (or very accommodating bean) like the Peru or a Colombian, PNG or Brazil and focus on being able to roast this bean consistently (at least 5 times in a row successfully) as a SO to your desired taste and then start to introduce a degree of controlled variation on roasting the same bean (e.g. roast depth) to see how your roasting profile affects the cup. Then try blending.
