Can the grind effect efficiency?

[timmi9191]

BIAB..

Have been using premilled grain from KK and getting good efficiency - 75%. +/- an OG point here or there.

First brew today with new mill. Set at approx .03 (credit card width) and got 65% efficiency. No other change in technique?

Any thoughts?

 

[QldKev]

Can the grind effect efficiency = YES

 

[timmi9191]

is my grind too thin or too thick?

 

[QldKev]

Too thick


These are pretty cheap
http://www.ebay.com.au/itm/0-02-to-1mm-17-Blade-Thickness-Gap-Metric-Filler-Feeler-Gauge-Measure-Tool-/300865188606?pt=AU_Hand_Tools&hash=item460cf672fe

 

[adryargument]

Credit card width i find is perfect for 3 vessel. Biab is pretty much powder.

 

[timmi9191]

Now I cant find the thread i was reading that set out reccommended width - I thought credit card was the BIAB width?

 

[Bizier]

Take a photo of your milled gain with a mm ruler for scale & post it.

 

[Rocker1986]

I BIAB and usually get somewhere between 70% and 80% efficiency using about a credit card width on the mill. :unsure: The last few have been around the 73-75 mark. My first one was probably about 65%. I can't remember since I lost all the records when my old computer crapped itself.

 

[CosmicBertie]

Definitely. The speed at which you grind can also effect it. I use a cordless screw driver which helps to keep the speed down.

I also use a credit card sized gap.

 

[timmi9191]

How does speed effect the efficiency?

 

[QldKev]

Faster it runs the more flour and more ripping of the husks you get. I noticed a great improvement in my crush when I switched from my geared cordless to a fixed motor.


With the setting of the mill, the feeler gauges I linked to earlier are only $2.16 posted!

 

[timmi9191]

Now I'm a bit lost..

Flour and ripping of husks is bad? Isn't a finer grind going to give u more flour?

 

[QldKev]

Also if your mill is actually set to 0.030 it is already actually a fine crush.

As requested before, maybe post a pic showing the crush
Also have you checked your scales for calibration?

Finally this is only 1 brew, maybe do another and this was just a bad day for efficiency.

 

[timmi9191]

Will do another grind and post pic.

Will double check scales but am sure they spot on (swmbo - expensive digital cooking scales)

Just to clarify things:

Is finer better for BIAB?
Is too fine a grind a bad thing?

 

[QldKev]

Finer is better for BIAB, as long as you are NOT ending up with a concrete slab in your bag



edit: Added word NOT, doh!

 

[slash22000]

Concrete slab is about right. I had my mill set too fine for my first BIAB attempt (basically looked like a bucket of flour) and almost shattered my spine trying to lift the bag.

 

[timmi9191]

Concrete slab?

 

[slash22000]

If you grind too fine and it's basically just powder, it turns into "goo" in the bag which prevents liquid flowing through. So when you try to lift it, the wort doesn't flow through the bag (or it does very slowly) so you're trying to lift a shitload of wet grain along with who knows how much wort at the same time.

Spine = history

 

[SimoB]

I wasn't hitting my OG, using the new Mill timmi. I did about CC thickness and found was a bit thin for my 3v set up. I'm thinking it is something else for me though, sparge and boil off rate is calculated properly i think.

Keen to know the perfect grind gap for 3v too.

Hopefully you get it right mate,

 

[QldKev]

There is not a perfect gap for all systems for 3V. I think starting at 0.9mm is a great place, and is where I have left mine. I use the same setting for both my 3V and 1V systems as I'm too slack to keep changing it.