Questions on gravity, projected vs actual
Hello, I have been doing all grain batches for over a year now and have stumbled onto some issues. When I first started, I took hydrometer readings to measure original and final gravity. My hydrometer had a colored in areas for "wort" and "finished beer" and as long as my reading was in the proper area, I was ok with the result.
For whatever reason, I started caring a lot more about gravity reading about a month ago. I went an bought a refractrometer and started testing my brews. I found that all of my beers were way off. I went about making a new mash tun, thinking I was losing too much heat during mashing. I kept track of every part of the brewing process, still my numbers are way off.
For example, Saturday I brewed an Oatmeal Porter. Grain bill: (note this is a 1 gallon batch)
1# 6oz American 2 row
1oz Crystal 120l
4oz Flaked Oats
2oz Black Patent
I mashed in with .5 gallon of water @ 165 degrees, mashed at 152 degrees for an hour and the temperature after an hour was 150 degrees. Not too bad. I sparged with 1.75 gallons of water @ 170 degrees, had a preboil volume of about 2 gallons. 1 hour boil and my OG after chilling was 1.030. According to the recipe I generated from Hopville, the OG should have been 1.049. My numbers are way off, not sure what I am doing wrong.
Frustrated, I put my beer in the fermenter and shrugged it off as another flawed brew. Today I was talking to a coworker and he suggested maybe trying another software, maybe Hopville was wrong.... I tried Brewformulator, Beer Recipator and Brewers Recipe Calculator and got 3 different results 1.041, 1.023, and 1.028.
So my questions are, what am I doing wrong/what should my OG be? Do the brewing softwares use different values for grains I am not seeing? I know 5 gallon batches are the norm, is there a flaw in scaling these recipes back?
The resulting beers taste good, but it bugs me thinking that they could be better. Sorry for the marathon post, thanks for reading and for any help.