Another neverending fermentation/low FG

[chipwitch]

Hello everyone. This is my first post, though Google has referred me to this site NUMEROUS times, I only just joined. I'm fortunate enough to have a homebrew store just a few minutes from my house, but depending who's on duty, they can be very unhelpful, sometimes downright snobbish and rude.

I'm on the fence about whether or not to invest my time in a brew that I fear may result in gushers and/or so dry a beer as to be unpalatable. Should I toss it? Let it sit in the secondary for another month then reevaluate? First, a little background...

I started making wine less than a year ago, using mangoes from a prolific tree in my yard. After making a few 5 gallon batches, I decided to try my hand at something a little more immediately gratifying. Since my first Norther Brewer kit about 4 months ago, I've made 2 extract kits, 3 of my own design extract batches (tweaked recipes found online), 1 2-gallon all grain, 1-partial grain and 1 5-gal AG. The last 3 have been full boil. I have not been particularly happy with any of the ales to date. Rather disappointing. However, I have gained some experience in my short time at this, read extensively and spent a lot of money trying to do this right without going overboard.

My question pertains to the last one, the AG. Like I said, I'm not overly happy with any of the brews I've made, but there isn't any great problem that makes any undrinkable and generally, I know what I did wrong. But the AG batch has me perplexed.

Here's the recipe...
Strong Golden Ale

10 lb Maris Otter
1 lb Munich Malt 5.5 SRM
1 lb Red Wheat Malt

Sterling Fuggles and Hersbrucker hops
Whirlfloc tab
Wyeast 1388.

2lbs of inverted sugar syrup was added when the gravity got down to about 1.025, a 2-3 days into fermentation.

It's been 25 days since brew day. Currently in glass secondary carboy. Gravity is at 1.005. Still lots of bubble (never stopped completely). Taste is good by my palate, lightly carbed in fact. Clarity is horendous (completely opaque in the graduated cylinder). Looks like apple cider, color (maybe a little more golden) and clarity. Smells pleasant.

Known mistakes/issues:
1) Iodine test revealed full starch conversion, though I didn't check gravity until it was in the boil pot which was around 5 points lower than target 1.070

2) Underpitched yeast. Stupid mistake. I made a 2 liter starter (no stir plate, oxygen or heat) about 30 hours in advance of pitch. After refrigerating for a few hours, I incorrectly expected most of the yeast to fall out of suspension. By decanting, I disposed of much of my yeast. duh. I realized my error in the middle of pitching and ended up pitching about a third of my liquid along with the sediment... so not a complete loss. The fermentation kicked off within 10 hours of pitching and proceeded nicely for few days as expected, tapering off but never stopping.

3) In the middle of transferring to the primary, I noticed fruit flies! This is Florida. Bugs abound. I doubt it is completely impossible to keep them all out brewing outside. Got 1 visible adult fly and about a half dozen floating larva in the brew, but looks like nothing alive.

I kept the primary in an ice water bath for about 4 days... temperature avg 66F. Ramped and held at about 72F

I'm going to check the gravity in a couple days to see if there is change. Right now, it's mildly boozy but drinkable in my mind. Mouthfeel is meh. I don't have the beer tasting experience to know off flavors. The only homebrews I've ever had are my own, though in the past 6 months I've sampled just about every ale I can get my hands on and love most of them. I don't know diacetyl by experience, but there may be a little in this brew.

Any suggestions? I'm not sure where to go from here. I appreciate any help.

 

[ncbrewer]

I'm a little concerned about the fruit flies and possible infection. Did any of them get into the wort after it was cooled below about 160F?
Also, what was the mash temperature? Low temp can result in a highly fermentable wort.
What was the OG? I guess it must have been well above 1.065 after boil-off. (And the invert sugar added to the total fermentables.)
Fermentation might be finished - airlock activity might be from off-gassing.

 

[chipwitch]

I found one fruit fly in the fermenter. I assume it got it after chilling since there were larvae. As for mash temp... my goal was to keep it around 156, but as I was mashing, I discovered how bad my thermometers were. So, I'm not exactly sure. One mercury thermometer for lab was reading in excess of 218F boiling water. I'm near sea level and weater was great. Should have only been 212. Freezing water registere a couple degrees below so the scale was off. I tried to compensate for it during the mash and tried to hold the temp at 160 based on the faulty thermometer. That was the figure I came up with assuming the error was linear... but that was no guarantee. I immediately bought a thermapen... so next time. Even had it been low temp, I only mashed for 55 minutes.

The OG was 1.070 post boil. Sorry if that wasn't clear. Should have been about 75. I ended up a half gallon short post boil.... still trying to dial in my equipment. This was my first full size batch AG with this setup. So, instead of topping off, since I was five points shy of my target, I left it alone.

The sugar raised the gravity, but since it was added a couple days into the ferment, the gravity reading would have been useless. Since the sugar adds 34 points per pound ( I'm certain) then there was a total of 418 points of sugar divided by 5 gallons. So, the adjusted "OG", taking the sugar into account would have been around 1.083 or so. Isn't 1.083 to 1.005 an indication something is wrong? Infection? How long can off-gassing continue assuming there is no infection? None of my previous batches have done anything like this.

 

[ncbrewer]

It seems to be about 94% attenuation, and maybe still fermenting. You'll find out about fermentation being finished or not when you check SG again. Maybe since it was your first full size AG batch, the temp was still low - you can hope. But it may well be infected. I'm not familiar with that yeast, but I agree 1.083 to 1.005 is probably a bad sign.

As far as the thermometer calibration, you method of linear adjustment between freezing and boiling is the normal method as far as I can tell. Here is an article from BYO: http://byo.com/departments/item/412-calibrating-thermometers-techniques

Off-gassing can continue even without fermentation - I think it's from the CO2 being over saturated and coming out of solution.

An infection on your first AG batch is a real drag - same thing happened to me. I think I traced mine back to wild yeast from the grains. Ended up replacing the fermenter bucket. I wish you luck.

 

[chipwitch]

Off-gassing can continue even without fermentation - I think it's from the CO2 being over saturated and coming out of solution.

Should I stir/agitate (gently, of course)?

An infection on your first AG batch is a real drag - same thing happened to me. I think I traced mine back to wild yeast from the grains. Ended up replacing the fermenter bucket. I wish you luck.

Wild yeast from the grain? How did that happen? Crushing grain near your fermenters? I would think boiling would eliminate that possibility otherwise.

 

[ncbrewer]

No need to stir, and it would risk oxidation and contamination.

Grain comes with wild yeast and bacteria. I crushed in a separate area, but mashed in near where the fermenter would later be filled. It might even have been close when mashing in and creating dust, but I don't remember for sure.

 

[madscientist451]

Use a yeast nutrient next time you make a big beer.

 

[eastoak]

fruit flies have all of the souring bugs you need to sour a beer and if your beer went from 1.007 to 1.005 then it's a safe bet you have an infected beer.

 

[LostBoyScout]

Based on all that sugar plus the chance you were actually mashing quite low based on a 4-6 degree error, I'd say it's entirely possible your beer dried out to 1.005 without infection. Since there's not a lot more sugar left I'd probably be willing to bottle now if it were me, though waiting another week isn't a bad idea. If you did bottle, I would aim low on the carbonation, maybe 1.7 volumes? And then just make sure to open one every couple weeks to see.

 

[chipwitch]

Use a yeast nutrient next time you make a big beer.

I have the last couple times. I really messed up on this starter though. Putting some in when I pitched the yeast might have been a good idea since I decanted prematurely.

 

[chipwitch]

Based on all that sugar plus the chance you were actually mashing quite low based on a 4-6 degree error, I'd say it's entirely possible your beer dried out to 1.005 without infection. Since there's not a lot more sugar left I'd probably be willing to bottle now if it were me, though waiting another week isn't a bad idea. If you did bottle, I would aim low on the carbonation, maybe 1.7 volumes? And then just make sure to open one every couple weeks to see.

There's a possibility the temp was NOT low. I did try to compensate for the error. I caught the error at the very beginning of the mash and calculated the adjustment necessary based on the error being linear. Now, if the diameter of the capillary tube in the thermometer was inconsistent then all bets are off. Could be anything.

I was under the incorrect assumption that as long as the iodine test showed no starch, the mash was complete so I transferred to the boil pot. Even though I tested each running with a refractometer, it didn't click that my numbers were a little low. From now on, I will plug into a calculator to determine what the gravity of each running should be prior to mashing. Had I done that, I would have mashed a bit longer. That would have helped with the low gravity? I think I was off about 10 points into the pot iirc.

Now, being a newbie, I'm a little unclear on the whole sugar drying out thing and attenuation. First, to be clear, there is no sucrose as this was an invert syrup. So, should just be glucose and fructose. I don't know if that matters. So, if a yeast can attenuate say, 75% that means (for simplicity sake) that yeast would take a beer from 1.100 to 1.25, no? But, if that 1.100 was partly sugar then it will attenuate lower than 1.25? Doesn't that contradict the whole concept of "attenuation?" With wine, what I'm used to is there is no such thing as attenuation. It's 100%. The only limiting factor is alcohol tolerance. It actually makes making a sweet wine difficult.

Now, the 1.7 vols... Of the 5 beers I've bottled all but one are nearly flat. The 3 most recent have been in the bottle at 74F for about 3 weeks or more. One is highly carbed... not dangerously, but more foam in the glass than I'd hoped for. I carefully measure and calculated for about 2.3 vols on all the beers. Again, I use invert syrup for priming. So, I'm afraid I've been under carbing. If I shoot for 1.7 I might not get much at all. I assume you're suggesting 1.7 because of how gassy it is still? That's my concern with bottling this batch.

 

[chipwitch]

fruit flies have all of the souring bugs you need to sour a beer and if your beer went from 1.007 to 1.005 then it's a safe bet you have an infected beer.

That's what I always heard. I've been trying (and failing miserably) to make real mango vinegar with wild acetobacter. For close to a year I've tried several times. Leaving my mango wine open it just won't sour. I don't get it. I've even tried different formulae. Straight mango wine. Wine with water... Wine with sugar, wine with water AND sugar. Wierd huh?

I've recently come to think that all homebrew is infected. You just can't help it. There are so many microbes floating on the air, any exposure is going to get something in your beer. The microbes on that lone fruit fly couldn't possibly ruin a beer by itself, I wouldn't think. Those microbes would have to compete for resources with the yeast. All those resources are gone before the infection can grow to a population of 100,000 cells. Not to mention that the alcohol created by the yeast, pH too, makes an environment inhospitable to most everything. I'm sure that's oversimplification, but that's how I see it. Consider that a gram of dry yeast has 5-20 billion cells depending on who you ask. It would take a hundred fruit flies to equal a gram, I'm guessing. And they only carry the microbes. The trick is keeping the infection small enough that the off flavors are undetectable. In a lot of ways, I see it like a lawn. Once you understand grass is a weed, keeping the lawn nice is a matter of sowing enough of the weed you want to make it impossible for the ones you don't want, to grow... but you still get weeds!

 

[ncbrewer]

Now, being a newbie, I'm a little unclear on the whole sugar drying out thing and attenuation. First, to be clear, there is no sucrose as this was an invert syrup. So, should just be glucose and fructose. I don't know if that matters. So, if a yeast can attenuate say, 75% that means (for simplicity sake) that yeast would take a beer from 1.100 to 1.25, no? But, if that 1.100 was partly sugar then it will attenuate lower than 1.25? Doesn't that contradict the whole concept of "attenuation?"

Yes, my understanding is that attenuation will be higher if part of OG is sucrose, dextrose, or glucose. So with the same OG, FG would be lower. No contradiction here - attenuation is not a constant. It depends on how fermentable the wort is, the strain of yeast, and other factors like stress on the yeast, and maybe how the yeast feels that day.

 

[LostBoyScout]

Now, being a newbie, I'm a little unclear on the whole sugar drying out thing and attenuation. First, to be clear, there is no sucrose as this was an invert syrup. So, should just be glucose and fructose. I don't know if that matters. So, if a yeast can attenuate say, 75% that means (for simplicity sake) that yeast would take a beer from 1.100 to 1.25, no? But, if that 1.100 was partly sugar then it will attenuate lower than 1.25? Doesn't that contradict the whole concept of "attenuation?" With wine, what I'm used to is there is no such thing as attenuation. It's 100%. The only limiting factor is alcohol tolerance. It actually makes making a sweet wine difficult.

Now, the 1.7 vols... Of the 5 beers I've bottled all but one are nearly flat. The 3 most recent have been in the bottle at 74F for about 3 weeks or more. One is highly carbed... not dangerously, but more foam in the glass than I'd hoped for. I carefully measure and calculated for about 2.3 vols on all the beers. Again, I use invert syrup for priming. So, I'm afraid I've been under carbing. If I shoot for 1.7 I might not get much at all. I assume you're suggesting 1.7 because of how gassy it is still? That's my concern with bottling this batch.

I'm not an expert myself, but invert sugar is still a 'simple' sugar that will ferment out basically completely. In other words, your FG should be about the same as it would be without the sugar addition, despite the increase in OG.

I have had the opposite experience with my stronger ales, they tend to carb up significantly despite my under-pitch of priming sugar. So that's why I suggested a lower rate, but if you have different experiences I would disregard my suggestion. But yeah, it was to account for a little bit more attenuation in bottle. Definitely the best option is to just give it a little more time and see what happens.

 

[chipwitch]

I'm not an expert myself, but invert sugar is still a 'simple' sugar that will ferment out basically completely. In other words, your FG should be about the same as it would be without the sugar addition, despite the increase in OG.

I have had the opposite experience with my stronger ales, they tend to carb up significantly despite my under-pitch of priming sugar. So that's why I suggested a lower rate, but if you have different experiences I would disregard my suggestion. But yeah, it was to account for a little bit more attenuation in bottle. Definitely the best option is to just give it a little more time and see what happens.

Yes, invert is simple sugar... specifically glucose and fructose. You think like I do. I can't get it out of my head and if someone can show me why, I would be appreciative. Many things I've read have left me with the impression that if your beer didn't finish low enough that throwing in some sugar would somehow bring the FG down more. I don' t see how that's possible. The reason it stops at a certain FG is mainly a function of the unfermentable sugars. Adding more fermentable sugar won't change that. Someone correct me if that's wrong.

So, then there's the idea of attenuation... I don't understand why the yeast stop at that point. Why would Wyeast say this yeast is attenuates at 78% if it will go to 90 if I just add sugar. So, I'm inclined to believe there is some machination that is restricting the yeast going much beyond the published attenuation. Is that screwy thinking?

 

[hou_me]

I think it's a bit early to call it infected since it smells and tastes fine and there's no pellicle, but you're certainly not out of the woods yet. I suspect that your fermentation temperature is too high. Also, when you took the OG, did you adjust it for temperature? That can sometimes throw you off a couple of points.

-ben

 

[chipwitch]

I think it's a bit early to call it infected since it smells and tastes fine and there's no pellicle, but you're certainly not out of the woods yet. I suspect that your fermentation temperature is too high. Also, when you took the OG, did you adjust it for temperature? That can sometimes throw you off a couple of points.

-ben

You think the temp was too high? Couldn't be! I apologize if I've said anything to the contrary. I have another thread going where high temps are being discussed, but I shouldn't have implied such in this thread.

This batch was fermented from the start in an ice bath. The temp of the fermenter (plastic) an inch above the water line was held fairly constant around 65F for 4 or 5 days. Plus, this was wyeast 1388, a high abv tolerant Belgian strain.

Yes, I always adjust for temperature, the gravity readings. Besides, the OG was determined by refractometer where it's less significant an error, then converted to gravity.

 

[chipwitch]

I was under the impression that only paying members could upload pictures.

If that's not the case, I'll post a couple of the carboy. I don't like the looks of it. It reminds me of something between clarified butter and apple cider. There's some stratification in it that's been there for at least 2 weeks now. Maybe that's normal? I've only made dark beers previously.