Missing Wort

[UsernameTaken]

My water in minus loss to grain, minus loss to boil, minus racked to cube is consistently 1.5 litres under in the kettle.

I have rechecked and rechecked my markings on the kettle and they are accurate.

I have measured the water going in one 5 litre jug at a time.

My starting volume and loss to grain and boil can change depending on what I am brewing, but my kettle is still consistently 1.5 litres under at the end!

Anyone got any theories?

Cheers,
UNT

 

[S.E]

minus racked to cube is consistently 1.5 litres under in the kettle.

You mention racked to cube but then say 1.5L under in the kettle, do you mean it’s under in the fermenter or under in the kettle before the cube?

If in the fermenter after it has cooled in the cube have you allowed for expansion pre cooling?

 

[manticle]

How are you calculating your losses?

Are you calculating loss to trub and deadspace?

 

[TwoCrows]

weigh the water in the jug, maybe under, also your boil of rate may be more than you think.

 

[UsernameTaken]

28 litres into the urn = 28 in the urn
3 litres lost to grain = 25 left in the urn
3 litres lost to boil = 22 left in the urn
16.5 litres into cube = 5.5 left in the urn

But I only have 4 litres left in the kettle!

1.5 litres unaccounted for?

 

[malt junkie]

how much grain?????

 

[UsernameTaken]

Varying amounts of grain depending on what I am brewing. Anywhere from 5 to 8 kg!

1.5 litres of missing wort at the end regardless!

 

[TwoCrows]

Approx loss to grain is 1 litre per kg if you drain , 0.8 if you squeeze the bag.

 

[UsernameTaken]

After I lift and squeeze the bag I loose between 2 and 3.5 litres depending on grain amount.

My grain amounts vary between 5 to 8 kg!

 

[manticle]

Any answers to my questions above?

 

[UsernameTaken]

After I have racked to my cube I pour what is left in the urn into a 5 litre jug leaving nothing behind in the urn!

 

[manticle]

How are you calculating what your losses should be as opposed to what they are?

 

[UsernameTaken]

I measure out 28 litres of water in multiple 5 litre jugs to fill my urn.

I have texta marks on the plastic tube at the front of the urn at 1 litre increments and they are consistent with my 5 litre jugs measurements.

After I pull the grain out and squeeze the bag I look at the water level on the plastic tube and it says 25, so I have lost 3 to the grain.

After the boil I again look at the water level on the plastic tube and it says 22, so I have lost 3 to the boil.

My plastic cube holds 16.5 litres, I used to treat it as 17, but 16.5 is more accurate for hot liquid as measured with same 5 litre jug.

So after filling the 16.5 litre cube I cannot read my plastic tube as the remaining liquid is below the 10 litre readable level.

But simple maths (22 - 16.5) tells me there must be 5.5 litres left in there.

But when I pour it into my trusty 5 litre jug there is only 4!

 

[warra48]

Are you allowing for shrinkage (well, you know what I mean) of the liquid as it cools from boiling?

 

[UsernameTaken]

I was not aware of shrinkage! Is this a thing?

The wort is still above 80c when racked to cube!

 

[mattyh77]

I think it's your cube. The plastic will expand when placing hot water in
My 20l cube will actually take 23-24l of hot wort.

 

[UsernameTaken]

Yes, I have measured this and it's 16.5 of hot liquid.

 

[Dozer71]

And 16.5L of hot liquid (+90) is around 15.8L of room temp liquid (that shrinkage thing warra was on about). Shrinkage from boiling to room temp (20C) is around 96%.

So the volumes post mash and post boil when cooled (to compare to initial volume) are actually less than the volumes above. On 25L this is 1L, plus allowing for rounding between multiple measurements may take it to 1.5L.

PS. Did you look under the kettle, could be there

 

[MHB]

On a 25L wort, 1.5L is about 6%, you say its consistent.
When something is consistently out its usually a measurement error.
Wort contracts about 4% between 100-20oC
Your jug could easily be out by a bit. and that gives a cumulative error (25/5 = 5* measurements, error of 6% is 1.2% error on each measurement)
Also its a good chance that its a bit of A and a bit of B added together.
Mark

Oops M

 

[UsernameTaken]

So at what temp does this shrinkage occur?