low OG high FG--how to fix

[tennesseean_87]

So my ex-brew partner brewed his first AG by himself, and got 60% eff on an octoberfest so the OG was about 1.042-4. It also underattenuated, and stuck at 1.03. He pitched some more yeast, and I haven't heard back since. If it doesn't start, can we add some sugar to boost alcohol (its at 1.5% ABV now) and thin it out. I know that's usually not the answer, but this seems like a situation where it would be a possible solution.

 

[scinerd3000]

if those numbers are accurate then this beer is in some trouble. Personally I would try and pitch a large amount of yeast and see if it ferments lower. A few things could have happened....

You could have poor fermentability of the wort due to issues with mashing. What temperatures was this mashed at and for how long. If this is the issue it is probably can't be saved.

The sugar is sometimes an option but adding it to an already stuck fermentation at this level is pointless and a waste. It does add alcohol and thin out the beer but if it isn't fermenting as is, more osmotic preassure will not help the situation. How long was this fermented and what type of yeast did you use at what temperatures.

For this to get stuck at 1.030 and have only dropped 14 gravity points means something went very very wrong in the process...

 

[tennesseean_87]

It is biermuncher's oktoberfast using some washed notty. He repitched more notty recently. He was aiming to mash at 157 to keep it from over-attenuating and keep a malty profile. I think he started it colder in hte basement, but then he warmed it up by bringing it upstairs for a while. I know it has major problems, I'm just trying to find the best thing to do with it.

Maybe the thermometer was off and he actually hit 159-160 for the mash. If the additional yeast don't do anything, is adding sugar my best bet?

 

[scinerd3000]

I would try and repitch first and if not, scrap the brew. People may disagree with me however, instead of wasting the time and money on something like this, I would dump it. My guess assuming the yeast is ok is that your fermentability of the wort was compromised during mashing leaving a poor sugar profile for the yeast....160 is not egregiously high however you did not leave much room for B-amylase to do its work as well as some of the other enzymes. His recipe calls for 156-158 which is pushing to the edge of Beta's activity already and another 2 degrees may have made the difference.

I would try to add more yeast and possibly aerate slightly unless you're sure you did enough initially. Stuck ferments suck and sometimes it is the only way...If that doesn't work, I would dump it and not waste more time.

BTW- Did you check to see that it was iodine negative before sparging?

 

[tennesseean_87]

I didn't do any of it, but my partner didn't iodine test.

I'm not sure if we'll dump, sugar costs about no money at all. It might not get much better, but it may be worth it. I may have to go over there and taste it for myself to see just how sweet it is.

 

[dcp27]

rather than dump it, you can always try adding amylase enzyme (most LHBS sell it) to get it going. obviously not ideal since this was meant to be mashed high, but better than nothing if the re-pitch doesn't help. id try gently rousing & warming it up a lil first

 

[RichBenn]

I didn't do any of it, but my partner didn't iodine test.

I'm not sure if we'll dump, sugar costs about no money at all. It might not get much better, but it may be worth it. I may have to go over there and taste it for myself to see just how sweet it is.

You may have missed the point. Sugar won't get the existing malt to ferment more. That means it'll taste way too sweet. If it ferments more by adding to or rousting the existing yeast, it'll be good.