Mystery...well nearly.

[GeorgeW]

Pulled two ristrettos last night and got a big shock. Too quick a pour, sour, and the crema was way off. I had just been congratulating myself on everything coming together..right OPs, roasting now spot-on, 25+ pour and wonderful results time after time.
I roasted another batch of Monsooned and tried again this evening and it came to me what was wrong as I was tamping. I checked my digital scales with a weight and sure enough it was reading 8 grams above what it should have been. This meant that not only was my pf short weight but my roasts were anemic also given that the weight also determines the degree of roast.
New batteries solved the problem but I will have to remember to regularly check the scales are accurate from time to time.