OG a little low on partial mash

[evilhomer]

OG ended up a little lower then what beersmith said it would. Here's what I did, let me know if you see any flaws.

I converted a all grain Christmas recipe to partial mash, recipe ended up...

4.5lb gold LME
3lb pale 2 row
1lb 40l
1lb white wheat
.25 roasted barley
.25 special malt
1lb honey at flameout

also did a yeast starter, .5 gallons with .55lbs amber dme, I included that .55 into beersmith.

Held the grains in 6.8 qt at 154 for 60 minutes, sparged with 3.25 gallons at 168 in the brew pot for 10 minutes. Added the mash water, then went to a standard 60 minute boil with the hops and lme. Honey for 10 minutes at flameout then topped with .75 gallons preboiled water stored in my freezer.

Cooled, then poured into the fermentor through a strainer. Added the starter and a little more of the freezer water to hit 5 gallons.

Beersmith said 1.074 at 75% efficiency, I got 1.066. I run through a stainer because I don't use a hop bag. Could the honey have gunked up with the hops? I was under the impression it was pretty water soluble at those temps but if I remove the honey from beersmith it gives me a gravity of 1.066.

 

[mojotele]

The honey situation you describe is unlikely, and I think the fact that you get the gravity you observed when removing the honey is a coincidence. Have you done partial mashes before? If not, you can't reasonably expect to get 75% efficiency. And, it's impossible to tell why your efficiency was what it was without more data.

also did a yeast starter, .5 gallons with .55lbs amber dme, I included that .55 into beersmith.

Do you mean to say you included the 0.55 lbs of amber DME in your gravity estimate of 1.074? That would be one reason your OG came in low. A lot of those sugars get fermented out in the starter before you pitch it.

 

[dlester]

I agree with mojotele, you should probably expect around 65% efficiency with partial extract. When you rinse the grains, it takes some time to coax out the sugars from between the grains. A 65% +/- is not a bad thing, just compensate by adding more grain. You need to figure what your actual efficiency is and adjust your software so that you know what your getting at the end of the day. Then adjust your software so that it comes out at the number you expect.

Good Luck and keep brewing

 

[evilhomer]

This would be partial mash #2. Yes the .55 was in the starter, I figured some of the sugar would get eaten by the yeast but thought it would be better to add it to the recipe. If you take the .55 dme from the recipe it brings the estimated OG to 1.069

 

[mojotele]

This would be partial mash #2. Yes the .55 was in the starter, I figured some of the sugar would get eaten by the yeast but thought it would be better to add it to the recipe. If you take the .55 dme from the recipe it brings the estimated OG to 1.069

Well, that's a lot closer! Don't include the DME you use in your starter in your recipe. Once the starter is finished it simply isn't significant. It probably increased your gravity by 0.001 at most. If it bothers you, you can cool your starter in the fridge then decant most of the liquid off the yeast cake to pitch a lot less of the fermented malt liquor.

The rest is likely your actual efficiency differing from your expected efficiency. And, really, you weren't off by much. Braukaiser has a great site with spreadsheets that can aid you in gathering and analyzing data to improve brewhouse efficiency.