First time roasting espresso, sour and metallic flavors. Why?

[Joey]

I'm pretty much brand new to Espresso, got my Lucca M58 this week.

I have been roasting for about 2 years and have a pretty decent feel for my Huky. Far from professional.

I roasted some of the Sweet Marias Decaf Espresso Donkey Blend. The green beans were about 12-18 months old but have been stored in a sealed ziplock bag indoors.

After 24 hours I decided to give them a try. I pulled two shots (20g dose) and they were at 50g yield in about 18-20 seconds. Both were extremely sour, more so than some of my other under extracted shots. I ground finer to get 50g in about 30 seconds, better but still sour. So I upped my brew temp from 200F to 204F. Still sour. I gave up for the night.

After 48 hours I wanted to give it another go, this time I ground even finer and pulled a shot that was about 30g in 30 seconds. Still sour.

After 5 days I tried again. Less sour but more metallic flavor.

After 8 days I tried it again. Hardly any sour flavors but very metallic. What is going on here? None of the other beans (professional or home roasts) have given me this much trouble. I haven't tasted anything metallic in any other bean so I don't think it's the water or machine.

I've attached my roast profile too. I'm open to suggestions of any kind. Thanks for reading.

[edtbjon]

Well, your profile looks very good, but it's a bit on the light side. As decafs usually looks darker than they really are, you can go ahead and try roasting to say 10F higher than you are roasting in the example roast. You do have a good starting point, so to go through the development phase a bit longer in the same time I'd suggest charging e.g some 10-20F higher but keep the timing of the drying phase the same. That will set you up for going into dev.phase at a little bit higher RoR so that the phases are at similar times.
I have no experience with this particular blend nor do I roast very much for espresso, but I roast a colombian decaf for my GF and that coffee needs to look quite dark to fully develop. I usually roast that to 425-430F, without even coming close to cremation.

[SusanJoM]

Since this is  your first experience with roasting for espresso, it would probably be a good idea to work on non-decaf beans first.

Decaf beans are....weird....

Once you are sure you can 'roast for espresso' then it would be reasonable to try decaf that way.  Have you tried to roast this bean NOT for espresso?

[brew]

  Have you tried to roast this bean NOT for espresso?

Is this topic of "roasting for espresso" a whole bag of worms?  I have read that roasting shouldn't change for espresso or drip but i'm not sure that what i've read or been told is credible?

[SusanJoM]

  Have you tried to roast this bean NOT for espresso?

Is this topic of "roasting for espresso" a whole bag of worms?  I have read that roasting shouldn't change for espresso or drip but i'm not sure that what i've read or been told is credible?

Yeah.....start a new topic....it's quite controversial and probably should have it's own thread....:-))))

[Gregr]

That profile looks pretty great- another vote for the beans being the culprit. I wasn't surprised to hear that the shots were bad though-- one day off roast almost always tastes underdeveloped. The fast and high yield pulls probably also increased sour/bitter notes. And the beans are old so the cards were stacked against you. Grab something easy to roast like a good Guatemala or other Central that makes quality espresso and do a roast with similar numbers, let it rest for 3 days and you're gonna love it I bet.