partial mash efficiency

Hey everybody, I'm new to partial mashes and was wondering what a typical effieciency for a partial mash is, so I can convert my extract recipes to PM. I've been using the rule of thumb 1lb grains = .75 lbs LME, but I'm wondering if I'm overstating the amount of fermentables I'm extracting from the grain. All I'm doing is throwing a few pounds of pale malt into the brewpot along with my specialty grains, in a big nylon grain bag. I steep in about 2 gallons of water for 45 min at 150 degrees, sparge with a quart of 170 degree water. Is it safe to assume I'll get roughly a certain amount of fermentables out of this or do I need to get a hydrometer and start calculating my brewhouse efficiency? I'm not particularly concerned with exact figures, I just want the beer to taste good

I don't know the answer to that but I like your pug.
I have two pugs at home.
One is the troublemaker and the other is the smart, good, obedient dog....

You can estimate what you should get out but the only way to know is with the hydrometer.

I would assume 60-65% then take a sample before you start the boil and add the amount of DME exactly needed. This is what I did on my first and only PM and it worked very well.

boothbrew said:

I don't know the answer to that but I like your pug.
I have two pugs at home.
One is the troublemaker and the other is the smart, good, obedient dog....

Click to expand...

He's both the trouble maker and the obedient dog. He'll take a crap on the carpet just for making him take bath, but he's great with my son. When he was an infant I could leave him on the sofa (breifly) and Hercules would sit at his feat and watch over him patiently.


anyway, thanks for the replies. I'll just assume about 60%. I swore off hydrometers a while ago, but if I'm going to get more into PM I might have to get a bit more precise...

Honestly, I wouldn't worry as much about efficiency in PM, since more than 50% of your fermentables typically come from extract.

I'd assume an efficiency of 65%, so you're not at the low-low end of things, but not pushing any upper envelops either.

Along the same lines as this, I'm curious as to how one calculates brewhouse efficiency with a partial mash and partial boil. Is there a formula you can use to determine how much sugar you've pulled from your grains even though you've added DME to the wort?

Or can you just take a sample of the mash itself and plug it into some formula before adding DME (and later top-off water)? Such as x grain + y water "should" = z gravity compared to the actual gravity of your finished mash....does that make sense?

This is a bit confusing to me. I'm hoping there is a simple answer to it. Sorry for the semi-thread hijack, but it's sorta related.