Sugar addition question

Today I brewed a belgian golden strong ale, here is the recipe:

5 gallons

13lbs dingemans pils
1lb corn sugar
1lb belgian candi syrup (golden, .5L)
1oz FWH Sonnet 3.9% AA
1oz Sonnet 90 min
Wyeast 3522 on 20 hr starter

I also topped off with an extra gallon for a 90 minute boil.

Before the boil I took a brix reading, 17. Perfect, actually I even overshot. After the hot break, along with the bittering hops I added the sugar (on recommendation from the great Denny Conn). At the end of the boil, my gravity reading was 1.076. I also took several brix readings, reading anywhere from 17.5 to 19.8.

What could have happened here? My idea is that the sugar coild have carmelized and perhaps did not disperse throughout the whole wort? Thats all I can think of.

Thanks!

 

Does your refractometer automatically correct for temperature? That's the most likely culprit of your fluctuating brix readings. I'd trust your hydrometer. Unless you had sugar at the bottom of your bk you don't really have to worry about the sugar not being evenly distributed.

 

I thought the drop of wort used on a refractometer cooled to room temp so fast there is no temp correction.

 

I find that if I don't cool down the refractometer sample quickly, some of the liquid evaporates and gives me a higher reading than it should.