Extract and efficiency

[Buster Bunting]

Hello,

OK so I've got a bit of an issue.
When I brew, I write recipes on beersmith and set my efficiency at 68%. I figure lower is better at this stage.
I'm still having issues reaching my target pre boil and thus post boil OG.

I'm more often then not 10points lower then expected. 
Im brewing between two different system and still the same thing is happening.

My mash pH is always 5.3, mashing at 66C, collecting the exact amount pre-boil, I calculate run off so it takes an hour to fill my kettle the final runinnings are between 1020-1010 (pH~5.6)

What on earth is going on? 
Please help me!

[Peter Smith]

who is crushing your grains? is it a good crush ?

whats the base malt?  I get 10% difference between Gladfields and Bestz malts

also explain your mash tun or BIAB etc , I used to get 66% BIAB no matter what I did

[Buster Bunting]

Hey Peter,

Thanks for your reply.

I'm in Auckland and am buying crushed from Penrose. A leading LHB so would expect a good crush???.
One system is a friends borrowed (he never used it) insulted Farra50 the other is a rectangular chili bin mash tun.
Im using either GF american ale or Marris Otter.
Ive thought malt crush myself but these guys sell lots of crushed grain and would expect a lot of other people to issues too???

[Peter Smith]

post up the beer smith recipe . see the upload files button below,   Brewerscoop crush is not so out as to cause 66% , especially with Gladfield's which gives high eff imho no matter how you treat it..   volumes are really important, how much extra volume is in the bottom of the boil kettle when finished and has your  equipment profile in beersmith got this trub/waste  left over amount correctly entered...

If you are copying a recipe off this site, its critical you have equipment profile nailed

[Buster Bunting]

Nope I write all my own recipes.

I'll post the recipe for the next brew I do.

After the last brew i went though the equipment wizard and changed something that has thrown everything out.
I'm pretty confident my equipment profile is set up well. I've measured every last drop of everything (almost anyway) so i can tru and solve this mystery.

[Buster Bunting]

Here is the recipe. 

Thanks Peter

[Eddie Johannisson]

The crush is the first thing to look at. My efficiency went up when I got my own mill and I bought grain from the same place as you.

I sit at a just over 70% and that works for me. Finer crush will give me higher efficiency but also bigger chance for a stuck sparge and grain is cheap.

You can get a cheap mill for $135.00 today

[Rhys Williams]

And how are you measuring the 66c - if this is out you could be *actually* mashing much higher or lower.

[Buster Bunting]

Using a digital thermometer. The reading achieved whilst mixing the mash. I've also got two thermometers.

[Buster Bunting]

Yeah I've two hydrometers......
Good suggestion though.

[Peter Church]

are you adjusting the hydro reading for temp? if the wort is at 40 degrees then the missing 10 points will be from temperature

[Buster Bunting]

Yup.
Chilling wort to 20C before taking a reading.

[nofizznofoam]

I've tested this and the adjustment was a lot less than the manufacturer said