Gravity Is Down

[Diggles]

My issue is my wort OG is 1.033, which is way below the target 1.049. Question is what happened, why such a bit difference between the end OG and the predicted using the post boil gravity reading? What should I do differently next time? What to do with the wort ?

Doing a BIAB using 4L to every kg of grain used, so volume before mash was 16L, lost 2L in the

Mash vol = 16L, with 2L lost during the mash

Added 14L before starting the boil = 28L, lost 5.5L during the boil, leaving 22.5L.

36L boil kettle used, hence adding additional water before the boil. Should I have sparged the grain?

Started to chill in an esky with ice, but quickly fount I didnt have enough ice, so cubed at an approx temp of 70degC and chucked into the fridge. End of boil gravity = 1.005, which equated to 1.046 according to Beersmith, target was 1.049.

Placed into the fermenter (0.5L loss to the cube) so approx 22L in the fermenter without taking shrinkage into account. The volume in the fermenter looked way below my usual 23L mark, but cannot say how much for sure!

appreciate any help

Diggles

 

[cam89brewer]

is this your first AG brew? The 14 litres you used to add to the boil probably should have been used to lauter/sparge or mash out.... this would most likely make up for your loss in efficiency.

 

[stux]

The higher your liquor to grain ratio the more efficient the biab. Holding back 14L from the mash would affect your efficiency significantly.

If you are going to hold back that much water you really need to sparge with that water instead. A dunk sparge is good

 

[cam89brewer]

The OG that you were aiming at would equate to about 80% efficiency which not every one can achieve in their first few batches and especially with out collecting a second running from lautering. There may be a few other little things effecting your efficiency but this is probably your main problem. ( maybe key in 75% efficiency in your next recipe too to allow for losses..??)

 

[jakethesnake559]

Hi Diggles,

What was your grain bill?
I think 1kg/4L in a 16L mash would be your problem (4kg grain?).

If you want to end up with 23L into fermenter at 1.049, you will need about 5.5kg of grain and about 34L of water.
Being limited to a 36L pot volume, you can't fit all the water you need in the mash....you will overflow it when you add the grain.

You should definately try a sparge next time.
When you pull the bag, you place it in a sparge bucket with some hot water in it.
You can then add the sparge to the boil.

Check out the maxi-BIAB method on the BIABrewer.info site.
BIABrewer Maxibiab

The same site has a heap of info specific to BIAB and some experts who are really helpfull!!

Cheers,
Jake.

 

[Diggles]

Hi Diggles,

What was your grain bill?
I think 1kg/4L in a 16L mash would be your problem (4kg grain?).

If you want to end up with 23L into fermenter at 1.049, you will need about 5.5kg of grain and about 34L of water.
Being limited to a 36L pot volume, you can't fit all the water you need in the mash....you will overflow it when you add the grain.

You should definately try a sparge next time.
When you pull the bag, you place it in a sparge bucket with some hot water in it.
You can then add the sparge to the boil.

Check out the maxi-BIAB method on the BIABrewer.info site.
BIABrewer Maxibiab

The same site has a heap of info specific to BIAB and some experts who are really helpfull!!

Cheers,
Jake.

Mate,
You're on the money as to the pot issue, now thnking of buying a bigger one as the 36L is going to be a pain!

Regards

Diggles

 

[Diggles]

Hi Diggles,

What was your grain bill?
I think 1kg/4L in a 16L mash would be your problem (4kg grain?).

If you want to end up with 23L into fermenter at 1.049, you will need about 5.5kg of grain and about 34L of water.
Being limited to a 36L pot volume, you can't fit all the water you need in the mash....you will overflow it when you add the grain.

You should definately try a sparge next time.
When you pull the bag, you place it in a sparge bucket with some hot water in it.
You can then add the sparge to the boil.

Check out the maxi-BIAB method on the BIABrewer.info site.
BIABrewer Maxibiab

The same site has a heap of info specific to BIAB and some experts who are really helpfull!!

Cheers,
Jake.

Mate,
You're on the money as to the pot issue, now thnking of buying a bigger one as the 36L is going to be a pain!

Regards

Diggles

 

[Nick JD]

Was your OG reading corrected for the hot temperature?

 

[Diggles]

Was your OG reading corrected for the hot temperature?

I'm using the conversion Beer smith gave, using a reading of 1.005. Unless the conversion factos within the program are incorrcet!

Diggles