Episode #125 of the Stack Overflow podcast is here. We talk Tilde Club and mechanical keyboards. Listen now
30

Fresh off the roast, coffee has high levels of carbon dioxide and nitrogen (based?) gasses. These gasses will greatly contribute to retro-nasal activity as well as initial flavors (think carbonated water). The most apparent flavor one gets from this is metallic. At my work, 4 days is considered minimum for serving and tasting, although there's always ...


22

The flavor and aroma of the beans continue to develop for the first few days after roasting as the beans release gas (this is the reason some retail coffee bags have valves to let the gases out). The process is similar for bread, with some bakers preferring to let some types of bread rest longer than others. Right now I am actually drinking a cup of coffee ...


16

I assume you are storing them for a later grinding (likely just before preparing your cups of coffee). According to some sources 1,2,3, the main point is use it within a week. For more than that, it is preferable to freeze them, and in this condition, for no more than a month. A brief summary: For short term use (this week's coffee): Do not refrigerate ...


16

First of all, there is no difference in the beans themselves. They all come from either Robusta or Arabica plants. The roast doesn't vary either. You can use any kind of roast for your espresso, it's up to preference. What does change is the grind. Espresso grind is very fine - much finer than other preparations of coffee. You may find packaged coffee sold ...


15

In general, darker, arabica roasts have less caffeine. Arabica (as opposed to robusta) inherently has less caffeine in it naturally, and darker coffees have less caffeine since they have been roasted longer or at higher temperatures, essentially "burning" the caffeine out of the bean. EDIT For some science, Arabica is usually found to be about 1.2% ...


14

There are several ways to roast your own coffee at home on low budget: Pan This is one of the extremely minimalistic ways to roast coffee, but the degree of complexity is very high as the coffee beans need constant attention due to the nature of the heat that arrises only from one side. Oven This is likely one of the most common ways to roast coffee at ...


14

By far the easiest way to start at home roasting is with a hot air popcorn popper. You can get a used one for $5 at a thrift store or pay approximately $20 new for one. Or perhaps you already have an unused one laying around. There are also people and websites out there showing you great ways to modify or make them better with cheap addon parts or hacks. ...


13

Roasting coffee dark may be used because it is easier to create a consistently flavored bean, with less monitoring and concern for flavor profiles. In the case of Starbucks they are shipping so much of their coffee to so many locations and creating so much coffee at once that it may be easier to create consistency. The darker you roast the less the flavor of ...


13

Breakfast or morning blends are generally a lighter roast, but there is no industry standard for how light of a roast. As for differences between breakfast and morning blends, the key is in the word "blend". It is entirely up to the producer to blend different beans and different roasts and call it what they want. Edit: There are some differences in ...


10

There is a goodish guide for your roaster here. I'd also keep in mind that coffee has a cooling period after you "stop" roasting, where it will generally still roast to a darker level (or two). You need to try to finish your roast at a level or so lighter than what you are aiming for and let the coffee "cool" into your desired roast. I might suggest that ...


7

I have been roasting with the FreshRoast SR 500 for several months and have seen wildly differing advice from a variety of sources. Recently I found information from a few sources that when combined have resulted in some really nice roasts. The first piece of information I found was the temperatures for the heat settings of the FreshRoast SR 500: | ...


7

There is no actual difference between "espresso beans" and "coffee beans"; in reality, they are both just "coffee beans". When you see something packaged as "espresso beans" or "espresso roast" it is most likely just a dark roast designed to taste good when ground ultra fine and used to make espresso. When it comes down to it, the only thing that changes is ...


7

Ethiopian coffee ceremony cases from hundred years ago until now, they brew coffee just after the coffee bean cooled, they have no de-gassing time they solve this smoke like off-flavor problem with fine grinding and boiling once again after they pour coffee ground to the Jebena with hot water . Also, they roast coffee to Italian roast degree which has very ...


7

It will affect the flavor. Whether that's particularly noticeable depends on the bean, the roast you're going for, and how much variance there is in the roast. Whether it matters to you is a personal decision. In my experience, over-roasted beans are worth removing from a light roast (I tend to prefer city roast at darkest), even if they're not actually ...


7

Sorting done during the processing phase of coffee production (prior to roasting) is done in many places and can produce lots of coffee that look very different, but taste almost exactly the same. Peaberry beans may be sorted out (mostly by sight from what I understand) and sold as separate lots. Additionally size may be used and beans can be sorted with ...


7

The roasting process leads to water loss in all types of beans. Most beans start off at about 10-12% moisture and end up around 3%. My experience gives about 15% weight loss (shrinkage) for light roasts and around 20% on dark roast profiles. Example of a dark roast weight loss in my roasterie would be: Starting weight: 240# Roasted weight: 195# Shrinkage = ...


6

Rather than playing with electricity and wiring you could actually just move the roasting bed/area away from your heat source and accomplish close to the same thing. I started roasting with a popper as well. The hole in the popper was roughly 3 inches so I got a 3 to 4 inch duct adapter, a 4 inch flour sifter and mushed it all together, similar to this. ...


6

Bean density varies dramatically with roast level. The more roasted a bean is, the less dense it becomes. My guess would be that less dense beans would have more of a tendency to float and more dense beans would have a tendency to sink. However, I imagine that there are other factors as well. Grind size would affect the mass vs surface size of the ...


6

I think there are a number of factors influencing the current situation. The rise of micro/small and home roasters. This allows people access to fresher coffee. The acidic and bright notes in coffees tend to fade quicker than roast notes. Meaning these bright notes are more readily available to the consumer. Changes in coffee processing. Different ...


6

Strength is an interesting wording, but some people use it. Mostly, caramelized or burnt flavors get visible during the roasting process. Understanding Coffee Bean names as they relate to roast As you may see in that answer, Wikipedia enlists roast degrees and their profiles. I would like to summarize them here. 22 °C (72 °F), Green Beans: You may prepare ...


5

I recommend Sweet Maria's. You order online and the beans are shipped to you. They have many different varieties, including Ethiopian.


5

There are several websites that sell unroasted or green beans in a range of quantities and will ship. I have heard that Costco or maybe it was Sam's Club were selling them as well (albeit in larger quantities). Keep in mind that shipping can be prohibitively expensive for small quantities. I order 12 pounds at a time from Sweet Marias and they ship in a ...


5

I finally noticed that the chaff collection unit is actually several pieces that don't fit as well as they could. I took it apart and sealed the seams with high temperature engine gasket sealant. I then used the sealant to connect the vent hose to the top of the chaff collector (also a very rough fit). I still have some problems with cold air inflow on ...


5

The roasting chamber of your Gene Cafe is made of Pyrex (heat-resistant tempered glass), and leaving the old oils to accumulate and burn will cause the the inside of the drum to turn black. The darker material will likely change your roasting time, and the fouled glass will not allow you to monitor your roasts. Glass does not need "seasoning", so it should ...


5

Your first question isn't clear exactly. All drinkable coffee has been roasted first, as raw coffee beans are not edible. I've read that re-roasting beans isn't practical for some reason that I'm not clear on, but I agree with Peter Pei Guo's, comment about why you would want to re-roast coffee in the first place. Immediately after roasting, coffee beans ...


5

If you can run the kiln at sufficiently low temperatures and have a solution for stirring the beans, yes you could roast coffee beans. "Drinkable" on the other hand is a hard to quantify term. Ideally, you would roast the raw beans slowy until 200 - 230 C over a time window of 15 - 25 minutes, depending on desired darkness and roast type. This allows for ...


5

I suppose under-roasting and over-roasting are somewhat relative. I generally prefer a lighter roast (just after the completion of first crack) which might be under-roasted to some tastes. I've occasionally stopped a roast too early and then it's under-roasted to me (and I suspect anybody else) as well! In those cases, the coffee tastes sour and I don't ...


5

Distinguishing between end of first crack and the start of second crack can be very tricky. A lot has to do with the variety of beans being roasted and your heat application. What I think happened to you was that you lost control of your heat. At first crack your beans become exothermic (give off heat) and you didn't reduce your heat. What happened then is ...


5

Roast times can significantly affect coffee flavors, and a 2 minute roast profile is concerning. While I cannot say I am familiar with the process they are using, I do know a decent amount about the chemistry involved when you are roasting a coffee bean. My biggest concern would be internal development of the coffee bean. To give you a brief run-down of ...


4

Preheating your Gene Cafe lets you choose between life cycle of the roaster and roasting consistency. By preheating your roaster, you should be able to get more consistent roast times. In my case my garage is sometimes 50F and sometimes 80F, so a preheat cycle would certainly probably help. I don't do it though. Any machine has a finite number of cycles, ...


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