RyanJE wrote:I wanted to follow back up now on my "un-scientific" findings this weekend. I am a list person so here goes. For each brew session below pulled at least 3 shots.

- Froze Verve Sermon 4 days post roast (roasted 1/23).
- Dialed in at the time with unfrozen coffee to 18G in and 27G out for taste much to my liking. (also about 19-20% EY). To my recollection, first brew session was 5 days post roast. Had enough to last up to 14 days of shelf life.
- This Wed 03-01, I pulled out a frozen (about 1 month) jar of 200G (use 16oz wide mouth ball jars, no vacuum)
- First brew session was Thursday morning using the same exact parameters, etc. used for initial dialing in (dose, grind, temp, flow rate, bev weight, etc.)
- Taste was not great, somewhat sour and lacking actual flavor (lemon). Everything else was right on though, flow rate, body, extraction yield, etc. At most a few seconds fast.
- I was suspicious of 2 things:
1. freezing coffee does something weird & unexplained to suck out the character but still allows it to appear / act like fresh coffee
2. The coffee actually didn't "age" at all from an off gas stand point and was still too "fresh", hence the sourness from too much co2. My palate is not super refined so I don't know the difference between sour from a regular under-extracted shot and sour from one with carbonic acid (result of too much co2). Maybe it's the same?
- pulled again with exact same parameters Saturday, much less sour but still a tad.
- Pulled again Sunday same parameters very little to no sourness and much closer to what I remember with the coffee that was never frozen and consumed over 2 weeks.

So what does this all mean? I THINK maybe my coffee still needs proper rest after freezing or I should wait longer post roast to freeze it (7 days maybe?).

This is all just of course speculation on my part regarding coffee frozen for espresso. It still makes no sense to me why coffee frozen ASAP after roast then brewed after thaw tastes weird. I don't believe coffee can be too fresh for a regular brew method except maybe the first day post roast?

My next time using this coffee I am taking a jar out about 3 days before my first session in hopes it will be about 7-8 days post roast in theory. Will report back about shots and how it continues to hold up through a 4 day period of actual use.