What happened to my OG?

[Jeeperforlife]

I recently brewed what was supposed to be a Kolsch from a recipe I found on HBT. (AG btw) This was my first AG attempt. At the end of the sparge I took a sample to test gravity...I did this simply by dipping a ladle into the wort and cooling it to 60 before taking a hydro reading. (Visualize dipping ladle into wort...from top) My hydro sample came back way low...almost 20 pts. (IIRC OG was supposed to be 1.047 and my reading was about 1.029 or so) To compensate, I tossed in appx 1# of lt dme. At the end of the boil my OG came in at between 1.055 and 1.060...quite a bit higher than I thought. What im wondering...was the high OG due to the dme bringing up the gravity more than I thought, or should I have stirred the wort from the mash before taking a sample? This was a stovetop mash done with the grain in a bag if that matters.
Merry Christmas all!
Thanks!

 

[HomerJR]

I'd have to assume that one of your readings is off. I'm pretty sure that a pound of DME won't raise SG by 30 points. Did you stir the wort before taking the gravity sample? That sounds like the culprit, wort that was not properly mixed.

 

[Jeeperforlife]

No I did not stir the wort before taking my sample. I wasnt sure if that could be the culprit or not. Thanks for the reply. I guess the only downside is a badly discolored, hig gravity Kolsch...Im willing to bet it will still be drinkable beer though. Only time will tell...

 

[JesseRC]

Well probably you didnt stir enough, but you do know that preboil gravity includes a 1-2 of gallons of water that will be boiled off , and therefore will be lower than the post boil Gravity. Because of your 60-90 boil , you are essentially concentrating your wort.

 

[Jeeperforlife]

I did try to factor that in but I still didnt think that would account for almost a 20 pt difference...idk maybe i was wrong but i believe it was due to a lack of stirring the wort.

 

[wizardofza]

Your hydrometer is calibrated, right?

 

[malkore]

Lack of mixing. ANYTIME you are brewing an extract recipe, you honestly don't need to bother with an OG reading if the recipe came with an expected OG. Extract always gives the same gravity per pound of extract, per gallon of water.

Fermentation will mix it up for you, so really, as long as you add the right amount of water for the recipe, your OG can be assumed as 'spot on'.

 

[Sithdad]

... At the end of the sparge I took a sample to test gravity...I did this simply by dipping a ladle into the wort and cooling it to 60 before taking a hydro reading. (Visualize dipping ladle into wort...from top) My hydro sample came back way low...almost 20 pts. (IIRC OG was supposed to be 1.047 and my reading was about 1.029 or so)...

I believe what you just took was your pre-boil gravity, which will be lower than your post-boil gravity, since you haven't boiled off any water and concentrated your wort. With your pre-boil gravity and knowing how much water you boil off in 60 minutes you could calculate your post-boil gravity, but I have never done it. To compensate, if you wanted, you could add some water to dilute your beer or just leave it alone and have the higher gravity Kolsch.

Then again I may be totally wrong on this I am still pretty new.

 

[TechyDork]

What was your recipe and how much preboil wort did you collect?

If we had that information i am sure someone could plug it in to beersmith and tell you what your Preboil gravity should have been.

 

[Jeeperforlife]

The recipe was "Neals Kolsch" iirc from the recipe section. It was for a 3 gal batch so i had adjusted the recipe for that. My preboil volume was a little over 4 gal. Oh yea and my hydro reads 1.000 in cooled boiled water so I thought that meant it was accurate.