Scorched or Stuck?

[thrashandburn]

Hi all. Three weeks ago I brewed up an all grain Porter, here's the recipe:

O.G. 1.060
F.G. 1.010
Efficiency 60%

7# Maris otter 46.7%
4# Brown malt 26.7%
1# Flaked oats 6.7%
1# Caramel 60 6.7%
.5# Special B 3.3%
.5# Chocolate Malt 3.3%
.5# Carapils 3.3%
.5 # Brown Sugar 3.3%

1 oz. Challenger 60min
.5 oz. Fuggles 30min
.5 oz. Fuggles 15min

Wyeast 1028 London Ale

So, I haven't been getting great efficiency and this beer is a bit higher gravity than many of my previous brews so I thought I would compensate by calculating it for 60% efficiency. I mashed with 4.7 gal. and batch sparged with 5.2 gal. The thing is, this is more water than my pot can boil, so I put a small portion in a pot on my stove to boil and boiled the rest outside on my fryer.

I became so preoccupied with the boil outside that by the time I went to add the wort on the stove it was boiled down to a syrup like mixture. I didn't want to sacrifice gravity, so I added the syrup to the main boil. My O.G. ended up being 1.072, way above expected. I didn't know if this was due to a great increase in my efficiency, or the super condensed syrup I added.

After one week, the gravity was 1.031 and I was surprised it wasn't near complete and realized the temp was in the very low 60's like 62. So I thought it might be stuck. I wrapped a heating pad around it and got the temp to around 70 and stirred up the liquid in the bucket to try and kick things off. I took the gravity today, a week later, and it hasn't budged one point.

Then, I read that sugars in scorched wort are often caramelized and aren't fermentable.

So, if you've read this far, my question is, is it stuck or scorched wort that is causing this problem? If it's scorched wort, it should be ok to bottle right? Otherwise I plan on pitching more yeast at high krausen to try and get this beer to the finish line.

Thanks to anyone who can help.

 

[Dovage]

We'll I am a newb too but since it all wasn't scorched I don't think that's the problem. One week is not nearly enough time to fret about a stuck fermentation. Most of mine ferment for 3 weeks or so.

 

[thrashandburn]

Well normally I would agree with you except, the gravity hasn't moved even one point in a week, and there's no krausen on top or any visible sign of activity. The taste is pretty sweet but not so sweet that it's unbearable, it's more caramel sweetness. Given this, I'm banking on the fact that it's just residual unfermentable sugar from scorching but I was hoping for a few more opinions because I'm afraid to bottle this stuff. I don't want to bottle unfermented beer and have a bunch of bottle bombs. I also don't want to add more yeast unless absolutely necessary.

 

[IvanTheTerribrew]

Hey

I have a couple suggestions and thoughts,
did you make a yeast starter?
What was the viability of the yeast (how long since it had been bottled)
Did you properly aerate the wort before you pitched?

Also, since you ended up with an OG of 1072 you would have needed to pitched double the amount of yeast than your expected 1060.

My question about the scorching is this: how many gallons did you end up with versus how many you were planning on? Reason I ask is because total gravity doesn't change from evaporation. Meaning if you have X amount of sugars in your wort, that is constant(unless you add more stuff) and what can change is how concentrated or diluted it is with water.

gravity units (GU) = (SG - 1) x 1000

Ex 1.060 = 60 GU

there's a formula for total gravity which is

GUstart x Volumestart = GUend x Volumeend

So assuming you wanted a 5 gal batch,

60 x 5 = 72 x (X)

300 = 72 x (X)

300/72 = 4.16

So that means you boiled it down to a total of 4.16 gallons and that just means you have a more concentrated wort. If you had just added more water to get it up to 5 gallons you would have been closer to your expected OG. I hope that helps.

As for what you should do, I would probably just add a dry yeast pack after rehydrating it, put it at the appropriate temp, and see if it helps finish the beer. I'm sure other people who know more than me will chime in, cheers!

 

[thrashandburn]

Yes I made a starter. It was a 2 liter starter on a stir plate for 3 days, I doubt underpitching was a problem. I also aerated for about 10 minutes with a kitchen aid electric hand mixer on its highest setting. I've never had a problem doing that before.

As far as wort volume, I was pretty much right on my target of 5.5 gal going into the fermenter. I was a little under, more like 5.3 gal. So, concentrated wort is not the problem, and even if it was, F.G. really wouldn't be affected that much being you would expect the same attenuation from the yeast right?

I've been reading a lot about intentional wort carmelization for scottish ales and other big malty beers. Basically, one would put a small portion of wort in a separate boiling vessel and boil aggressively until it became candy like syrup. That is then added to the boil for increased malt and caramel flavors. Higher F.G. is mentioned as the sugars are unfermentable. The thing is, nobody talks about what F.G. you would expect from such a practice. I'm pretty sure that this is basically what I did on accident, I just don't know if the F.G. is higher than it should be given this fact. I was hoping someone would be able to tell me because I'm afraid to bottle it.