I have an IPA that I've brewed in five gallon batches before. OG at 1.065 and FG at 1.010. Those were hydrometer readings.
I scaled it down for a one gallon batch, and pitched half a packet of yeast (Safale US-05) instead of a full packet. My OG was 1.060 using a refractometer, but my FG is reading 1.041 after 2.5 weeks of fermentation.
Is something throwing the refractometer off? I haven't had this issue before.
Maybe I under-pitched? But half a packet of yeast for a one gallon should be plenty, right?