GySgtLynn

Recipes 

I was having similar problems, efficieincy in the 50's. I switched from a 60 min rest to a 90 min rest. Since I swtitched I have been getting mid 70's.

__________________
Liquid Medication Brewery

Primary: IIPA, Scottish EDxport 80, and Cream Ale

Secondary: None

Bottled: None

Keg: Hefeweizein and Crap-Tober-Fest

Starderup

Recipes 

Distilled water is not a good idea because there is nothing in it. You want some trace minerals for the yeast. I allow my sparge water to rest at least 15 minutes before lautering.
Check your crush, forget the stirring half way through, and double check your thermometers. Do an iodine test.

__________________
<priceless quote>My dog dropped his bone in my fermentor while I wasn't looking.</end quote>

KuntzBrewing

Recipes 

That'd work fine but the grain will give plenty of nutrients along with the sugar for the yeast, I actually think distilled is the best cuz the grain will add plenty of nutrients

Starderup

Recipes 

I'm sorry, but the common census says the opposite.
http://www.homebrewzone.com/homebrew_tips.htm
- Do not use distilled water as the full water base for your batch of homebrew. Use spring water or well water, but not city (chlorinated) water or distilled water. Distilled water lacks minerals and nutrients for proper yeast fermentation to take place.
(homebrewtalk wiki) http://www.homebrewtalk.com/wiki/index.php/Water
Distilled water has has all mineral content stripped from it in a distillation process. It is not recommended for brewing all-grain beer because some minerals are necessary for healthy fermentation. Distilled water is fine though for extract brewing because minerals from the extract manufacturer's water are already in the extract. Distilled water is also useful for diluting hard tap water.

__________________
<priceless quote>My dog dropped his bone in my fermentor while I wasn't looking.</end quote>

dezman

Recipes 

Is your efficincy problem a constant thing or was it just for this batch? If you are not getting the correct PH for you mash this could lead to efficincy problems. Mabe try different water or test mash PH and adjust accordingly if you can. Also I have read that a thicker mash increses enzyme activity. Try 1.25qts/lb see if that helps.

Also I heard 5.2 doesnt work very well. Not speaking from experience but have read many times that it fails to do the trick.

Your process sounds pretty solid so I would lean tward the above reasons. Also as mentioned before make sure crush of malt is good. If all else fails you can add and extra pound of malt to achive desired gravity.

soup67

Recipes 

It is a constant thing, although not quite as bad as I thought. (Hydro is reading 5 points low.) Explains why my beers, although a little low on OG, have all tasted really good.

Next brew I am going to look at the crush closely and test for conversion at 60 minutes, and then do a double batch sparge. If that doesn't get me where I want to be I will look into water chemistry.

Thanks to all who chimed in. This site is great.

BrewThruYou

Recipes 

When calculating the efficiency of the mash/lauter, you need to use pre-boil gravity and volume. If you boil it for hours down into a sticky goo, your efficiency does not change.

soup67

Recipes 

I hit 79% mashing with 1.25 qts/gal and doing a double batch sparge (with no change in water). I can live with that. Thanks for everyone's help.