Yeast affect on starting gravity

I brewed my third batch tonight (second try on the same recipe) and avoided many of the mistakes that I made last time (even though the beer from last time is still pretty darn good). I had a little bit of trouble getting down to pitching temps because I hadn't bought enough ice for my bath, but my biggest mistake was that I forgot to measure the starting gravity before pitching the yeast. In fact...it wasn't until about an hour and a half later that I remembered that I hadn't taking a measurement. So, I went and grabbed a sample and the gravity was way off from target. Target was 1.081 while actual was 1.054.

The question is: I know yeast can affect starting gravity, but can itaffect it this much or did I just mess up somewhere along the way? This is a double IPA recipe and the yeast is 2x Safale us-05.

Is this an extract kit? On a side note...Get some 2-Liter soda bottles fill them 2/3 with water and freeze them...great ice cubes.

Post the recipe and someone will give you a great estimation about what your starting gravity actually was.

it doesnt sound like it could have dropped that much in just an hour and a half, if fermentation had even begun at all, but I guess it is possible.. yea you definitely need to post the recipe so one of the big boys on this forum can diagnose your problem for ya

Partial mash as follows:

30 min Mash at 155:
2lbs 2-row
1lb light munich
0.5lbs crystal 40L
1tsp enyzme
1 gal water

Sparged into 2 gal at ~170 (let sit for 10 minutes per the easy partial mash sticky thread) then topped off with 2 gal.

Boil:
10lbs Pale LME for 60min
2 oz Nugget (pellet) for 60min
1 oz Nugget (whole) for 15min
1 tsp Irish Moss for 15min
1 oz Nugget (whole) for 0min

Transferred to primary, topped off with about a half gallon of cold water, pitched two safale us-05's between 75 and 80.

(and will do two dry hop additions of 2oz whole Nugget each time).

According to the Promash recipe from the LHBS I should have been at 1.081 (as I mentioned in my original post).

EDIT: now that I think about it, the easiest explanation would be that I didn't mix the top off water well enough with the wort. However, I think I shook the bucket pretty vigorously and it was only a half gallon of water that I added.

This is out of my league...But the only thing that jumps out at me is the 30 minute mash. Did you check for conversion? And what was your final volume? And the volume of your recipe design?

No doubt this is just a case of the wort not being mixed when the sample was taken. With 10lbs of lme and surely you had at least 50% efficiency even with the shortened mash, you would be well over 1.054 for a starting gravity. This sounds like a good beer and I bet it turns out great.

ezerhoden said:

No doubt this is just a case of the wort not being mixed when the sample was taken. With 10lbs of lme...

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Although normally I would agree with you, at 10# of LME at 5.5 gallons would be a starting gravity of 1.065. His target OG was 1.081. The gravity contribution from his mash would be 17 points. The difference between 81 and 65 is 16 points, and I could be way wrong...I've been wrong before, it's weird, that is what it was off.

Warped04 said:

This is out of my league...But the only thing that jumps out at me is the 30 minute mash. Did you check for conversion? And what was your final volume? And the volume of your recipe design?

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Did not check for conversion....was told by LHBS it wasn't that important based on the assumed efficiency (see below). Final volume was 4.5 gallons. Volume of recipe design was 5.7 gallons, so I was low in that regard using only 5 gallons total for the mash/sparge/boil.

ezerhoden said:

No doubt this is just a case of the wort not being mixed when the sample was taken. With 10lbs of lme and surely you had at least 50% efficiency even with the shortened mash, you would be well over 1.054 for a starting gravity. This sounds like a good beer and I bet it turns out great.

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I hope so, thanks! The promash target gravity was based on 50% efficiency.

Warped04 said:

Although normally I would agree with you, at 10# of LME at 5.5 gallons would be a starting gravity of 1.065. His target OG was 1.081. The gravity contribution from his mash would be 17 points. The difference between 81 and 65 is 16 points, and I could be way wrong...I've been wrong before, it's weird, that is what it was off.

Click to expand...

The boil was 5 gallons, not 5.5 gallons. 1 gal in the mash (I figure 0.5 gallons lost between mash and sparge), 2 gal in the sparge, 2 gal top off in the boil. Ended up with somewhere around 4.5 gallons and I then added around 0.5 gallons (which brought me to the 5 gal mark on my bucket).

Alright, well my numbers aren't right then ...Let's go with not enough shaking

Well, that's good I guess. I really made an effort to shake it well, too. Is it kosher to use a sanitized spoon to stir water into the wort rather than just trying to shake it to mix it up?

I don't see a problem with that.