Hello my esteemed baristas.

I've been off the forum for a bit while experimenting with my newly acquired millennium pro and while I'm very happy with it so far, I recently went to a lighter roast and the shots are decidedly sour. I've tried finer grind to the point where it almost blocks up. I've tried different infusion times. I've let the machine heat up a bit (normally I let it cool between shots) as well, but no joy.

I personally prefer the darker roasts but don't want to waste this 'opportunity' to learn something new about my Ms Pavoni.

The beans in question are a 'mocha java' blend from our local whole foods. Also, the beans actually smell very fruity and almost lemony to begin with but come out with no sour taste from a friend's Quickmill Anita.

Thoughts?

Intended post immediately follows.

Add a thermometer to your group and run the temperature higher. If your friend pulls these beans on another espresso machine with no problem, heat's the issue.

Adding Thermometry to a La Pavoni Europiccola

Tips for Controlling Brew Temperature on a Home Lever Espresso Machine

Thanks for the quick reply Doc. I can always count on you or Robert Pavlis for great insight on Pavonis. I'll get a thermometer and check it out. Will report back with the results for future newbies like me.

And now to figure out a (long overdue) gift for both you and Robert for all your help.

I think you need some fresh beans from a local roaster. I'll bet that anything at whole foods isn't as fresh as you think it is. Look on yelp in your area for a good coffee roaster. That's what I did and it made a huuuuuge difference. The guy I get them from roasts beans twice a week and I get a 1/2 pound from him every week.

Also, do what Gary said and check the temp of the group head. I use a thermapen and pull my shots when the group head gets to 188 degrees. Tastes perfect every single time.

Deejayc, the whole foods near our house posts their roast dates on their bins and I almost never use coffee older than a week because of that. This batch was actually warm when I got it (6/2 roast date).

I'll do the thermometer thing and report back.

In that case, it's too fresh. It needs to degas for 4-7 days. There's a lot of carbon dioxide in it now that will make it extremely sour until it's properly rested.

mgwolf, I'm assuming this only happens (sour taste) with medium to light roasts? Because I've never had this problem with darker roasts

I think the relevant test is whether your friend gets shots without the sourness using the same coffee aged the same amount. If so, if you adjust how you're pulling the shot you should be able to get similar results. Also some of the folks here are trying to lead you toward espresso blends that are well known on H-B, like Counter Culture Espresso Rustico. You might enjoy that too but may not need to do so to achieve your goal in this thread.