I'm liking the following decafs currently. I generally like Royal's selection, which shows up at more than one online retailer, such as Burman's, Captain's, Coffee Bean Corral, etc.

Colombian SWP Royal Select - balanced and clean at FC
Peru SWP organic Royal Select - came out with nice dark chocolate dominant at FC+

A favorite when I can get it is Guatemalan Royal Select MWP (mountain water processed), which is often great for espresso. Update 6/30: This is full-bodied, sweet and malty.

I've just roasted an Indonesia Sumatra Royal Select MWP and it smells wonderful but isn't ready to brew yet.

Royal also offers decafs in its Crown Jewel program, which requires buying or splitting 22 lb boxes.

When I share my home roast decafs with friends, they remark that it doesn't taste like decaf.

I am also about to try roasting decaf Robusta green that he sourced from Saka. I've always enjoyed the taste and mouthfeel of Robusta but can't tolerate it. I've wondered whether there's a stimulant in it that is not quite like the other caffeine in Arabica coffees but don't have the knowledge to confirm that. It feels different than too many cups of Arabica. Anyway ... here's the link to Matt's offer of Indian Robusta.

Decaf Robusta Green Coffee - Cantina Coffee

When I get a roast in, I'll start a thread so others can compare notes.

The decaf Saka blend is half Robusta. I'm able to tolerate it just fine. The decaffeinating process eliminates the caffeine and maybe other stimulant compounds. Added: I've roasted the Robusta targeting Full City and am waiting until it's ready for tasting to report back. Actual charge was about 15 sec earlier as the Charge button just wouldn't register. Added 6/30: My probes read higher than many others, so for your own roasts, consider when you hit first crack and the amount of temperature increase I logged before dropping. First crack was indistinct throughout and started with a few very early pops, so I marked its start when there was a cluster of pops. Usually my roasts hit 1C at BT of around 395-399°F. This is my first roast of this coffee -- both Robusta and decaf.



Tasting notes added 6/30, Day 8 post-roast: It's very sweet, with distinct nutty flavor that his a hint of peanut. That may be due to some under-ripe beans, but it's hard to tell. It's a pleasant flavor. There's a hint of berry fruit in the sweetness and not much acidity. There's a touch of astringency that may disappear with more rest. I'll try it as espresso and will report back. Day 9: As espresso, at this roast level, I would only use this as a blend component of maybe 10%. It's cloyingly sweet and fruity and a bit nutty, but not in a balanced way. At espresso concentration with just a couple of sips I can feel a bit of residual caffeine but not the jittery version I usually get with caffeinated Robusta. Conclusion: I would roast this into second crack like Saka does.

Added: 7/2, 10 days post roast. For a regular coffee I'd say it's fallen off and has gone flat. But since this is Robusta, I'll keep checking it. The sweetness has receded and it has a papery, astringent flavor. That kind of flavor note tends to age out, so I wonder if it mellows if aged longer. I'll report back.

Added: 7/4: There is another possible approach to roasting this coffee short of second crack. In a thread about roasting in the Neapolitan style, OldmatefromOZ suggested a method of introducing more caramelization that worked. He suggests a hot charge and soak, a strong gas dip at end of dry to achieve a slowed ROR, then increasing the gas at around 170C/338F to add enough energy to drive 1C. Here's the link to his method. I'll report back after trying that and am currently aging my first roast to see if it has indeed gone flat.

Added 7/11: The point of this post is to see what happens if I age decaf Robusta as some people age Italian coffees to mellow them. I brewed an AeroPress 17 days post roast. The unpleasant cloying sweetness is gone. It's mildly bitter and has a hint of roastiness and is hollow in the middle of the taste spectrum, i.e. at the middle of the tongue. The aftertaste is walnut. It's flat but not rancid. After cooling in the cup, some pleasant sweetness emerges so it's not so flat. Updosing may help. As an updosed espresso, it's creamy, but it's dominated by a papery flavor. Conclusion: Take it darker.