Biab 48% Efficiency Can That Be Right?

[hanzie]

Hi

I just did my first BIAB and my efficiency was quite low - 48%- can someone please check my brewsheet to see if i did it right. Or can do anything better next time. I didnt do the escolator mash and added the grain at 70c.

View attachment BIAB_blackbeer_16_6_8.xls

Also here is a picture of my crush. I did it myself in the HBS and the owner didnt give me any guidance on how much I was crushing it.



Another thing is I think my bag might be to fine its not swiss voile its some other voile(they didnt have any). When I lifted my bag it was huge and stoped draining very quickly. After lots of squeezing I got about 10L out of it. and an hour later there was another 4L that slowly driped out(that I discarded).

Thanks
HAnzie

 

[PostModern]

Not being a BIAB'er I have these observations:

1. You probably threw away most of your extract.
2. What was your recipe?

 

[SpillsMostOfIt]

If you got 10 litres into your boil and threw away 4 litres, and your extraction calculation did not take into account the stuff you threw away, you will see an extraction figure that is 4/14ths lower than you actually got. If that is the case, you probably also left a fair bit inside the baggie.

It sounds to me that your fabric store let you down. Here's a picture I took as an illustration for the thread on the BN:

The ruler is metric and the major graduations are centimetres.

 

[mfdes]

Comparing to my usual crush, you have a huge amount of intact grain.
The number one cause of low efficiency is poor crush: no matter what you do afterwards the efficiency will be crap if the water is not getting into your grain.
However I don't know what type of mill you used and that has a big effect on the appearance of the grain after crush.
Throwing away 4/14th of your mash is also important: it would reduce a 75% efficiency mash by 21%... to about 54%
That's starting to get close to what your numbers are... perhaps.

MFS.

 

[Jerry]

Comparing to my usual crush, you have a huge amount of intact grain.

MFS.

Same here. I think the grain needed to be crushed finer.

As others have said losing the final 4 ltrs has also contributed.

Scott

 

[Thirsty Boy]

Sounds like a bad bag to me.. it shouldn't drain like that.

Pulling figures out of my rear - I'd say that 85-90 % of the liquid should effectively just "fall" through the bag.

If you were shooting for a pre-boil of say 30L, here's how I would expect it to (roughly) go, assuming you don't have a skyhook set-up.

finish mash - grab bag and lift it mostly out of the wort for a second - pull it completely out of the wort and hold it there while the vast majority of the liquid drains out, maybe 5 seconds or so - heave it in a bucket - Hang the bag over the bucket from a door knob or whatever.

At this point I'd expect about 25ish litres in the kettle and maybe collect 5L or so from the bucket after it drains for 10-15mins and/or you give the bag a squeeze.

Sounds like yours was holding onto the wort a bit more tightly than that. If you PM me an address, I'll post you a bit of bag material so you can compare.

Also - looking at your brewsheet. Your expected efficiency was a bit ambitious at 80% For an anticipated OG of 1.055 I'd be thinking more along the lines of 72-74 at best. And you chucked away 4L that really should have gone in the kettle. Also, it looks like your boil was a bit of a concentrated affair because you were chilling with ice blocks.. so you threw away even more of your sugar than 4L of your final gravity would have been

Anyway, don't worry about it too much. The 1.044 will still make a nice beer and you will get closer next time.

Congrats on breaking your BiaB (and AG??) cherry. Here's wishing you many more.

Thirsty

 

[hanzie]

I think it is my bag its much finer than that photo. It took a good 10 to 20 min fo the first 10l to be squeezed out there was no running out. I will go to spotlight and try again.

1044 is not to bad at all I was planning on a 4%ish beer anyway. Cant wait.

Thanks guys