Trust my refractometer?
 

So I broke my hyrometer durring my brew session today, and my refractometer is giving me a OG of 1.073 or 17.8 brix but I was expecting around 1.065OG or 16Brix when all was said and done. I was taking measurements of my wort pre-boil and all were on track, last reading from both hyrometer and refratometer were 1.061 pre-boil. I've re-calibrated my refractometer with distilled water and I keep getting this reading. Should I trust it? My gut says no. My tastebuds say no (wort doesn't taste "that" sweet, but it's a pretty high IBU beer.). Thoughts?

It's probably more likely that the refractometer is better at telling between 1 brix than your taste buds.

Unless you dropped the refractometer, I'd say to trust it. Especially since it is calibrated both against distilled water and with a hydrometer reading from a previous wort.

If it is calibrated, trust it. If you still don't trust it, pitch it. Or donate it.

In addition to DI water, I wonder if there's another calibration liquid we could all use for mid-range calibration. Something like Coca Cola could work, no? Anyone know the OG on Coke?

Well, I will do a test tonight. I will grab a new hydrometer on the way home from work and test it against the refractometer. I have never dropped it, but it was purchased online and who knows how it was handled before. I get funky readings from it all the time.

Since you use such a small amount of liquid with a refractometer you do need to be careful of what's on the utensil you use and your timing if dealing with hot liquids. A rinsed and not dried spoon can lead to inaccurate measurements on the lighter_than_expected side due to the excess water remaining on the spoon. A non-rinsed, reused spoon can lead to inaccurate measurements on the heavier_than_expected side due to concentrated sugars left on the spoon. I always use a new spoon, or rinse and dry my reused spoons. Also, putting a small amount (0.5 ounce or so) of hot wort in a shot glass and letting it sit on the counter to cool can also lead to increased brix readings due to the evaporation that takes place during the cooling thus concentrating the sugars. Is it possible you ran into any of these scenarios, or others I didn't mention?

I was taking chilled wort going into the fermentor, in a small shot glass and using that as my sample, testing immediately.

Does your refractometer have a calibration screw? Many do.

Does it have auto temp correction?

That sounds like about a gallon of boil off assuming you finished with about 5 gallons in the fermenter. That's not really an outlandish number for boil off, so if it seems like you got about that much boil off I'd definitely trust it.

Try tap water. Calibrate to 0 brix with DI and then take a reading of your tap water. If your experience is the same as mine, it'll read 0 brix as well, or so close that it's not worth worrying about.