I recently received a refractometer and tried it out on a batch of mead that has been in secondary for about 3 months.
I took a reading of some distilled water, both read 1.00. I then dissolved 30g of sugar into 250ml of water and took a reading; both showed around 1.045.
However, when I measure my mead, I get pretty much exactly 1.00 on the hydrometer but 10 brix (1.040 sg) on the refractometer.
Interestingly, the mead tastes quite sweet; much sweeter than I'd expect from something at 1.000sg.
Can someone help explain what is going on here?