Pumpkin curse. Low efficiency brew day yesterday. Thoughts?

[cimirie]

So, I brewed my annual pumpkin ale yesterday. Smelled awesome, really excited about it! Unfortunately, this annual brew that I look forward to more than any other didn't go according to plan - at least in terms of final numbers.

7.5 lbs pale 2-row
2.5 lbs munich
.25 lbs 60L crystal
5 oz 120L crystal
3 lbs canned organic pumpkin (roasted in oven at 400* for an hour)
1 lb rice hulls

1oz cluster (60 min only)

2 tsp Cinnamon (all spices mixed and split evenly between 15min and 3 min)
.5 tsp nutmeg
.5 tsp allspice

Hit target mash of 152 dead nuts on (3.5 gal). Mashed for an hour.
Sparged with 180* (3.5 gal) in double batch sparge (2 gallons first run, 1.5 second time around).

Collected just over 6 gallons into boil pot.

60 min boil.

Target OG 1.052 Actual OG: 1.043.

I routinely hit 73% on my system. Kinda like clockwork. So this mid-60s efficiency threw me for a loop.

This is only the second time I've tried a double batch sparge. It worked awesome last weekend.

My method on double batch sparge: first 180* run I pour in my sparge water and let stand for 10 minutes. Drain over 15 - 20 minutes. Second run pour other half of 180* sparge water. Mix. Let stand for 10 minutes. Drain over 15 - 20 minutes.

I don't know if the double sparge method is the problem as it worked spot on for me last week with the exact same methodology, but it seems the likely culprit as the rest of my numbers were spot on. Thoughts???

 

[cimirie]

*Bump*

Not even a single view? I really need to work on more catchy thread titles!:cross:

 

[ChillWill]

Did you stir it like you life depended on it? Could be a number of things.

Maybe add some dme if you're really bothered about the og being short.

 

[cimirie]

I do a pretty good job stirring when I sparge. Perhaps not as if my life depended on it, but I think, pretty thorough.

Truthfully, I'm not worried about the OG in terms of final product. It's not as if 1.043 is unacceptably low (in terms of potential abv) and this thing has ALL the flavor. I'm just mystified as to what happened.

 

[asterix404]

So you don't need the rice hulls, did you wash them first to get them good and soaking wet? I wonder if you get better efficiency if you did the 3.5 in a single sparge. I can't think of a single reason that a single sparge isn't good enough and once the grain bed sets I would really just want it to sit. I wonder if the sugar wasn't broken down by the enzymes in the pimpkin, what was your expected sugar contribution from the pumpkin?

 

[cimirie]

Honestly, I hadn't calculated the sugar contribution from the pumpkin. I know it would have been present, but I had no way of knowing exactly how much. The estimated OG was based solely on the grainbill.

As to single vs. double sparge... I recently have read up on both methods. The overriding sentiment is that a double sparge will give you a few points in efficiency. But, if this is the consistency I can expect from this method, I might go back to a single batch sparge.

And why don't I need rice hulls? I have done a pumpkin mash without them. Not fun. No, I didn't get them wet ahead of time.

 

[asterix404]

So I wouldn't have figured that you needed rice hulls since you have so much grain and I would think that intact hulls would allow a mash to not get stuck. If you have had a stuck mash, by all means it doesn't hurt anything, but I wonder if the rice hulls sucked up sugar and didn't let it go during a sparge. I really don't see much else wrong with this and I might try it again. Could it be grain crush? I know I am pulling at straws but you used about 10lb which should give about 1.054.

 

[cimirie]

This whole thing has me flustered. I hadn't thought about crush. It's not a bad thought at all. On the flip side, my LHBS crushed this AND my Optimator clone (that I did last weekend) at the same time on the same machine and that efficiency was solid (above average, actually).

Rice hulls can absorb some of the sugars? I don't use them at all unless I have a heavy oatmeal concentration or am using pumpkin. If the hulls CAN absorb the sugar, that could be the culprit. Anybody else have this happen to them with rice hulls?

 

[Ravenshead]

Rice hulls are not an issue.

Your process sounds pretty solid too.

However, you did mention that this only the second time you used this process. That's not enough brews to tell how well it works with your system. You need four or five at least to establish consistancy.

That being said, what kind of process were you using before?

 

[cimirie]

Same process on every step except the sparge. Previously did a single batch: pour in sparge water, mix, let stand for 15-20 min, drain over 25-30 minutes. Pretty constant at around 73% eff.

Glad to hear rice hulls not the issue. The thought of learning another brewing equation to compensate for rice hulls annoyed me! Didn't they were the culprit but glad to get a second opinion.

 

[Ravenshead]

It's probably not your process then. Doesn't sound like your crush either. That leaves only leaves a bad hydrometer reading and bad luck.

I'm certainly out of ideas.

 

[Clementine]

Same process on every step.

Don't forget the pumpkin is in there messing with how the sugars run out of your MLT. I'm not experienced enough to lend a real opinion. However looking at it from a scientific point of view variables from recent brews are sparge and pumpkin (possibly water depending on your source, tap water changes regularly). What notes do you have from your Pumpkin brew last year?

Clem

 

[Ravenshead]

The pumpkin should be adding sugars not reducing them. That's why pumpkins make good pies.