Pre boil O.G figures way out

[Richard Brown]

Wondering if someone can explain an issue I am having measuring gravity with a hydrometer.

I have started recording preboil gravity readings from my bull dog brewer. I run the wort off from the tap at the bottom of the boiler into a cylinder and the cool to RT before taking my reading.

Trouble is that the readings I'm getting are massive e.g. 1.054 when I am shooting for a post boil OG of 1.042. And this remember is preboil. Before the wort is concentrated through the boil.

I did wonder if the wort at the bottom of the boiler may be more concentrated than that at the top (post sparge). Anyone experienced similar?

 

[simon12]

You are either getting much higher efficiency than you calculated for, your using more grain than you thought, you have used less water than you should or the hydrometer is wrong, there should be no difference between wort from the bottom or the top.

 

[Mungri]

Wondering if someone can explain an issue I am having measuring gravity with a hydrometer.

I have started recording preboil gravity readings from my bull dog brewer. I run the wort off from the tap at the bottom of the boiler into a cylinder and the cool to RT before taking my reading.

Trouble is that the readings I'm getting are massive e.g. 1.054 when I am shooting for a post boil OG of 1.042. And this remember is preboil. Before the wort is concentrated through the boil.

I did wonder if the wort at the bottom of the boiler may be more concentrated than that at the top (post sparge). Anyone experienced similar?

I was getting the opposite from my Grainfather, taking the sample from the top. ie a lower preboil gravity than expected. Then I read the instructions through again and they do say "NOTE give the wort a good stir before taking preboil SG". Since I've been doing this preboil gravity has been more or less as expected.

 

[simon12]

Maybe i'm wrong then, are what are you post boil reading like?

 

[Mungri]

Maybe i'm wrong then, are what are you post boil reading like?

Post boil readings have always been fine.
Like yourself, I wouldn't have thought there would be any difference from the bottom to the top, but my preboil and post boil readings were so far apart for a standard 60 mins boil.
I knew it couldn,t be right.

 

[Richard Brown]

Sorry should have waited until I got my post boil figures to explain fully.

My OG (post boil gravity) is 1.050. A fairly big overshoot on the aimed OG of 1.043 (I am fine with this as my boil off rate was higher than normal and this is a new recipe still to be refined).

However it still doesn't explain why the preboil gravity (1.054) is higher than the post boil gravity (1.050), strange! Cheers for the replies

 

[Richard Brown]

Ahh just read the replies in full. So it seems there is a layering in the wort after sparging

 

[simon12]

I did have that issue but it was down to a tiny leak in a plate chiller watering down the wort during cooling.

 

[Horners]

Are yoy sure you are correctly adjusting hydrometer readings for temp?

 

[BeerCat]

Get a refractometer and you wont have to worry about temp adjustments and takes 10s to get a reading.

 

[Sadfield]

Certainly sounds like wort stratification. Give it a stir before taking a sample.