Density PROBLEMS

I know its impossible , but i don't know why before boiling i am getting 1.053 of density and after boiling i am getting 1.035, how is this possible? i was trying o many ways of sampling, but all the time the same, this is happening in my 100lts batch, in my 20lts batch everything is fine, PLEASE HELP ME

Beer stratifies in any container with just a little time. Before measuring gravity, whirlpool it gently to homogenize the liquid, you'll get much more accurate readings.

Sugars don't dissapear.

I know, but actually i am taking the density right after whirlpool , after cooling and in the ferment tank , and all of them are getting very low , around 1.035, the thing that make me very worry, is that pre boiling is around 1.050, so how can be so different?, 0.015 points under? i am very worry, because i don't have answer at all!!!

Scientifically, that doesn't make sense. You're boiling off water and leaving the sugar, concentrating the wort. If you're adding top off water and not mixing it thoroughly, that could cause a lower gravity reading.

Assuming you're using a hydrometer and not a refractometer, try to make sure that when you take your reading that the temperatures are consistent across the board. Different temperature wort will show different readings.

For example, wort leaving the mash tun at 154 degrees may read 1.077, but if you cooled that down to 68, it would read something like 1.060. Check to see your temps are consistent, I used to forget about that ALOT.

Cheers!

I am using hydrometer , and i am correcting the reading with temperature, and i was taking samples a different time, but still the same. I was doing two more batches and exactly the same, i can't understand, and it just happen with my 100lts batch, because with 20lts batch everything is perfect. ANY RECOMENDATION PLEASE? Anyways the beer is good, but i can see the different body against the 20lts batch.

It has to be sampling errors. 100 lts are *huge* amounts. *How* do you boil 100 liters? What equipment do you use? Normally I assume the pre-boil wasn't mixed and the post-boil was better mixed but your results imply the opposite.

But trying to imagine how you would go about boiling 100 liters is ... well, mind boggling. I have to assume the huge volume leads to great stratification.

Are you taking you sample from the top of the fermentor or the bottom of the fermentor?

Well, basicly i am using kind of the same equipment but with 120 liters vats , of course the power of fire is huge.
I was thinking the same, that maybe i am not mixing properly the pre boil must.
The samples are coming from the bottom and from the middle of the vat.
thank you very much