OG is consitently low on partial mash brews?

[BioBrew]

I've brewed about 10 batches of beer now. After my first batch I moved to partial mash. Every time my OG comes out quite lower than the recipe calls for. Today I made a stout and (according to an online calculator and the recipe I found) the OG was supposed to be around 1.084, but I ended up with 1.055. The bill was as follows:

Two 3.3 lb cans of Dark LME
1.75 lb DME
1 lb Roasted Barley
1 lb Crystal 50L
.5 lb Chocolate Malt
.5 lb Briess Black

I got my temp up to 165° to steep my grains for 20 minutes. Temp waved a bit, but kept it between 160° and 168°. Brought wort to boil and added all the DME and LME, along with hops and maltodextrin. After the 60 min boil I added the mix to my fermenter and mixed in the water. At the 5 gal mark at 68° my measured OG was 1.055. I am usually about 0.010 or so away from the estimated OG, but this was by far the worst I've been off.

I read about different problems with sparging and taking measurements when working AG. The water was stirred quite well in before and after taking each measurement. I tried to keep the temp consistent as I was adding water. Any suggestions and tips would help very much. Thank you!

 

[Yooper]

I've brewed about 10 batches of beer now. After my first batch I moved to partial mash. Every time my OG comes out quite lower than the recipe calls for. Today I made a stout and (according to an online calculator and the recipe I found) the OG was supposed to be around 1.084, but I ended up with 1.055. The bill was as follows:

Two 3.3 lb cans of Dark LME
1.75 lb DME
1 lb Roasted Barley
1 lb Crystal 50L
.5 lb Chocolate Malt
.5 lb Briess Black

I got my temp up to 165° to steep my grains for 20 minutes. Temp waved a bit, but kept it between 160° and 168°. Brought wort to boil and added all the DME and LME, along with hops and maltodextrin. After the 60 min boil I added the mix to my fermenter and mixed in the water. At the 5 gal mark at 68° my measured OG was 1.055. I am usually about 0.010 or so away from the estimated OG, but this was by far the worst I've been off.

I read about different problems with sparging and taking measurements when working AG. The water was stirred quite well in before and after taking each measurement. I tried to keep the temp consistent as I was adding water. Any suggestions and tips would help very much. Thank you!

First, that recipe isn't a "partial mash". What happens in the calculator when you change it to "extract" (which is what your recipe is)?

 

[BioBrew]

After more research I now understand the problems with my terminology. I used beer calculus first to find my OG, but I believe that takes into account using the specialty grains for a partial mash instead of merely steeping them like I did. Then I tried The Beer Recipator. I selected extract w/specialty and went on from there. Now I have an OG of around 1.024. This is much lower than my measurements.

I understand that by steeping I am not getting as many sugars from the specialty grains (or at all) as I would if I partial mashed.

This brings into light many of the differences I find when looking up recipes and making them. I feel quite foolish and ignorant. Thanks for your help and sorry for wasting your time.

 

[Yooper]

After more research I now understand the problems with my terminology. I used beer calculus first to find my OG, but I believe that takes into account using the specialty grains for a partial mash instead of merely steeping them like I did. Then I tried The Beer Recipator. I selected extract w/specialty and went on from there. Now I have an OG of around 1.024. This is much lower than my measurements.

I understand that by steeping I am not getting as many sugars from the specialty grains (or at all) as I would if I partial mashed.

This brings into light many of the differences I find when looking up recipes and making them. I feel quite foolish and ignorant. Thanks for your help and sorry for wasting your time.

Oh, no, you weren't wasting anybody's time! I just have some experience with brewing software (I typically use Beersmith) and I know if you check the wrong box and chose "partial mash" instead of "extract", it won't recognize that it really is an extract batch and give you the correct projected OG- it'll just give you a higher OG which is incorrect. I just assumed that was happening with your software, too.

With an extract batch, you can almost totally discount any of the grains giving you much in the way of OG points. You can use the 6.6 pounds of LME and the 1.75 pounds of DME and count on having an OG of 1.063 +/- in a 5 gallon batch, assuming you topped up to 5 gallons.