Mysterious gravity drop

red96jeep · 02-03-2012, 09:07 PM

So im working on a problem that has surpassed my knowledge. Today i brewed a batch of Belgian golden we were looking for a sg of around 1080. Our pre boil gravity read 14.5 plato after boiling off 1.5 gal and adding 32 oz of liquid beat sugar out sg read out on a hydrometer as 1052 and 13 plato on the refractometer. This stumps me, after a volume reduction and addition of further fermentables how can the gravity reading drop? Any insight on this issue would be appricated

chickens4life · 02-03-2012, 09:12 PM

did you take your preboil reading after collecting all of your wort and mixing it well? if the sample contained more first runnings than second runnings it would be much stronger than the average gravity of the total run off.

That's all i can think of

red96jeep · 02-03-2012, 09:18 PM

Yes pre boil was taken after 40 mins of runoff and well mixed wort. The final runnings of the mash were 5 plato as well. It is a possibility but i find that hard to believe as the reason.

chickens4life · 02-03-2012, 09:33 PM

Other than that I don't see anything that could have caused a loss of total sugar, it makes no sense to me at all.

**GuldTuborg** · 02-03-2012, 09:44 PM

Maybe the liquid beat the sugar right out of the pot?

Most odd errors of measurement come down to instrument error, reading error, or incomplete mixing. In your case, the later FG was verified with 2 instruments, and the boil should have taken care of mixing the wort well, so that must be correct. The initial measurement was done with only 1 instrument, and one that we assume would work based on its calibration with your hydrometer, so that's all out, too. That leaves mixing of the wort for the preboil measurement. Are you sure the various runnings were properly stirred up in the pot?

red96jeep · 02-03-2012, 11:06 PM

yes, i am absolutely sure the mixing of the wort after runoff was done completely, not only was the wort ran into the kettle using a tube filling from the bottom up, it was also stirred and allowed mixing time before the sample was taken. im wondering if using a liquid sugar solution in the boil as opposed to the traditional hard sugar may have been the issue? this was my first time using the liquid solution, is it supposed to be added during fermentation only?

**GuldTuborg** · 02-03-2012, 11:16 PM

Did you make the liquid, or did you buy it premade? Either way, do you know the exact amount of sugar and water in the mix? I suppose if it were dilute enough, you're right, it could be the explanation. I imagine it would have to be pretty dilute to account for the numbers you saw.

red96jeep · 02-03-2012, 11:42 PM

I used two 16oz (32 oz) premixed liquid solution packs that were marked 1.033 ppg each. I worked under the assumption that two of these pack would then add about 3 plato to the gravity.

**Yooper** · 02-04-2012, 01:08 AM

Did you cool the samples to under 100 degrees before reading and then correcting for temperature? I know the temperature correction tables go up to higher temperatures, but they are notoriously inaccurate over about 90 degrees. Under 90 degrees, you can get a good reading by reading the hydrometer and then using temperature correction. Or did you use the refractometer only for the preboil gravity?

**GuldTuborg** · 02-04-2012, 01:58 AM

Quote:

Originally Posted by red96jeep

I used two 16oz (32 oz) premixed liquid solution packs that were marked 1.033 ppg each. I worked under the assumption that two of these pack would then add about 3 plato to the gravity.

Assuming these are marked as fluid ounces (being a liquid and all), you added a quart of 1.033 liquid. Did you add them pre or post boil? Either way, it's actually going to bring your gravity down, but not nearly by what you saw. There's also no way these will add 12 points to your gravity. So at least we know why you didn't get to 1.080, but it still doesn't explain why your gravity dropped after boiling off 1.5 gallons (how confident are you in that measurement?).