199-201 was my sweet spot. 204-206 became my "sour" spot. I don't think I have enough of the Kirkland Espresso beans to make a valid test again. And honestly unless my local Costco begins stocking them, I don't think I will bother ordering them again. They're good but not $6-$7 more good than the Kirkland House Blend which is exceptionally good especially considering the $10.99 price.
Also for the record, one setting on the Breville I did not disclose and even though I did not change it I think it's important to note. I can set the following parameters on it. "Bloom time, brewing temp (IIRC from a low of 175 up to 210), flow rate (slow, med, fast, though I have never timed them). During this little experiment I had not mentioned I am using the "slow" flow rate"
There are 3 presets. Fast, Gold, and Strong as well as Over Ice, and Cold Brew. Since I have no interest in Cold Brew, or Over Ice brew, I have never paid much mind to them. And one other curious thing I've noticed. In Gold setting, the machine does not do a "bloom". Rather treating the bed of beans (as does Moccamaster) to some initial "agitation" to stir the bed up. As to what "flow rate" I am not sure but when I "temp" it, it seems to hover just over 200 (between 200 and 205).
But I don't know and none of my research shows what flow rate the brewer uses on Gold. Though I suspect it's somewhere close to (if not) the medium flow rate, given the turbulence I see in the bed of grounds when through brewing