Efficiency Calulations...help Me?

[pokolbinguy]

G'day folks,

Wel I have my boil under way for todays brew and I have a distinct feeling that my effiency has hit a real low point.

Grain bill (Dr Smurto's Golden Ale):

2.4 kg Wey Pils
0.8kg Wey Munich I
0.8kg Wey Pale Wheat
0.25kg Wey Caramunich I

Mashed for 90mins at 66deg and topped kettle volume to acheive a boil volume of approx 29L .....I think this is way to much and I think this might be the issue...I cant see me losing 9L during the boil....

Anyway my pre-boil SG was 1022.

I was aiming for 1036...so big difference.

My question is how do I calulate the effiency and is there any way I can save this brew from being a watery drink.

Should I boil for longer?? I am doing a 90 min boil...and the first 30 mins just clicked by so time to add some hops.

Post boil SG should be 1047.

Any suggestions on how to up the SG would be great...I have a feeling I have stuffed this mash up ... I guess I could always use some dex or similar to up the post boil SG??

Cheers, Pok


P.S Can I use beersmith to do the calulation?

 

[cdbrown]

My pre-boil volumes are always around 30L and end up with 21L and that's a 60min boil. Vigorous boil with the lid off and you'll get a lot more evaporation than beersmith calculates.

What efficiency have you got entered already in beersmith to say you should have 1.036 in the kettle?

 

[pokolbinguy]

My pre-boil volumes are always around 30L and end up with 21L and that's a 60min boil. Vigorous boil with the lid off and you'll get a lot more evaporation than beersmith calculates.

What efficiency have you got entered already in beersmith to say you should have 1.036 in the kettle?

Efficiency is set to 70% at the moment. I assume this is not too high or low for an "assumption"....I have never calculated my own efficiency.

I figured I would just wait till the end of the 90 min boil and see what I come up with...can always boil longer if I have to buy dont really want to do that.

Boil is fairly vigorous and lid is off...plenty of steam coming off that puppy.

 

[cdbrown]

i get about 70% efficiency, although my first lot of brews were around 60%. If you put in 60% do you get the pre-boil OG about right?

I don't think you'll need to increase the boil length as that's just going to change the impact the hops have on the brew. You may still end up with an OG you wish, but at a smaller volume because of the lower efficiency from the mash. It just happens sometimes.

 

[pokolbinguy]

it comes out about right when I put the effeciency to 50%.....hmmm....I will see what SG I have at the end of the boil and we'll see whats going on.

Pok


OK.....So stupid me forgot that you have to take into consideration the temperature of the liquid!!!.

So seems like things might be better than 1st anticipated and may just be smack on where I wanted it to be

Simple things!!!

 

[hughyg]

it comes out about right when I put the effeciency to 50%.....hmmm....I will see what SG I have at the end of the boil and we'll see whats going on.

Pok


OK.....So stupid me forgot that you have to take into consideration the temperature of the liquid!!!.

So seems like things might be better than 1st anticipated and may just be smack on where I wanted it to be

Simple things!!!

I was thinking of suggesting temperature obscuration! How'd it finish up? I always boil of about 9L for a 23L batch (actually more like 9L for a 25L batch)

 

[pokolbinguy]

So I ended up with approx 19L (so lost 10L to the boil) with a temp adjusted SG of 1051....

Will top it up with about 3L to fill my cube and should be nearly whack on the mark


Anyway how do I work out the efficiency of this brew???

 

[seemax]

4kg base malt, 0.25 spec grains...

Very rough its approx 300BD/kg so 4.25 * 300 = 1275pts

You ended up with 19L of 1.051 (or 51BD) = 969pts

Your post boil efficiency = 969/1275 = 76%