Question about decaf bitterness

[Gatewood]

I have found that my decaf (ordered online, and I get it the day after the roast), while fantastic the first couple of days, will give me a bitter espresso after that. I don't think it's the beans, as I've tried two different decafs. My other coffee, which I roast myself, doesn't do this. I figured it was me, but used the nekkid portafilter on it yesterday, and the pull was absolutely picture book. Downright beautiful! But it was bitter. Not a sink shot, but bitter nevertheless. I haven't roasted my own decaf, as I understand it is harder to do, but can somebody tell me, does decaf get bitter after just a few days? I can't figure this out. If I was getting bitter shots on the regular coffee, I'd know I was doing something wrong, but the other coffee is fantastic. Help?

[another_jim]

Decafs stale faster and have less acidity. Both will make the taste balance out on the bitter side. The best fix is to brew it cooler. Decafs are not a good match with lever machines, which tend to run hot. If you are using a lever, your best shot is to use a light roasted, fairly acidic coffee that's been decaffed -- a straight Kenya, Colombia, Guat, or Ethioian coffee are ideal, while low acid ones like Brazils or Indos should be avoided.

[Gatewood]

Thanks! I'll keep that in mind, and am much relieved. Yep, my machine runs hot. It's a EPG-8.