Final Gravity Too High

[Wfu1bunn]

I brewed a Russian Imperial Stout that should have had an original gravity of 1.103 and a final gravity of 1.022. OG was actually 1.045 and FG was about the same. I did have a major blowoff for a day and I'm thinking my fermentation temp was too high. I used a yeast starter as well. Can someone tell me why FG was so high or what might have caused it? I can provide more details, but generally what causes this?

Thanks.

 

[ArkotRamathorn]

Just to be clear, what was your original gravity? Was it 1.045 or did you hit the expect OG of 1.103? If it was 1.945 and you measured again later at 1.045, then there wasn't much fermenting going on. What yeast did you use? What does your recipe look like? You could try warming it up and rousing your yeast up(sanitize a long spoon and gently stir up the yeast cake at the bottom).

The yeast may have just got lazy and decided it was done. Or if you used old extract/lots of specialty malts, this may be the natural final gravity.

 

[alane1]

Seeing that you had a major blowoff, fermentation did occur. I would suspect your hydrometer is broken. calibrate it and if 60deg tap water reads 1.045 you might want to chuck it and get a new one.

 

[Qhrumphf]

Well, we need more information. I have a hard time believing your OG would be off by that much without you immediately knowing something was wrong. But for an RIS of that gravity, that's a good FG if you ask me. Edit: I misread, I thought it finished at 1.022, not 1.045. So no, that's a little high.

Complete recipe?
Actual batch size vs. recipe batch size?
Fermentation temperature?
Is your hydrometer calibrated? As in, does it read 1.000 at its calibration temperature (most hydrometers are either 60F or 68F, it'll be printed on the hydrometer itself)?
What temperature are you taking readings at?

 

[Wfu1bunn]

Recipe is:

12oz British crystal malt
10oz British chocolate malt
3 oz roasted barley
3 oz British black malt
10.5 lbs light dme
1lb cane sugar
5.3 oz black treacle
2 oz Target bittering hops
1tsp Irish moss
Wyeast's 1084 Irish ale yeast
Danstar cask and bottle conditioning yeast

OG was 1045. Would temperature of wort affect OG reading? Wort might have been too warm. Checked gravity the other day and it was 1040. Target OG was 1103-1104 and FG was supposed to be 1022-1024.

It was a pretty vigorous fermentation. Had major blowoff first day. Didn't have blowoff tube. Airlock kept getting blown off and I would replace it when I realized it was off. Batch might be contaminated as well but it doesn't taste bad, just pretty sweet.

It needs to age for about 7 more months(I've bottled it by the way). Trying to decide whether to pour it out or not.

Would love to understand what went wrong so I don't do it again.

Thanks for the help!

 

[Wfu1bunn]

It was a 5 gal batch

 

[Qhrumphf]

Unless your batch volume was WAY off, that OG is impossible. You basically would have had to have a 10 gallon batch to hit that gravity. The DME alone will put you at 1.094. for 5 gallons. Presumably you topped off with water before taking the reading, and you grabbed predominantly water, not wort, because they weren't properly mixed. If you had a 5-5.5 gallon batch, you're going to be about 1.100-1.105 range or so. If you had a bigger batch it'll be low. But like I said, to get that OG you would have noticed something wrong. Not possible to miss like that with extract unless you either didn't add all the extract, or if your batch gravity is way off (again to reach that kind of error it'd have to be literally missing half the extract or doubling the batch size).

So, if you added everything you're supposed to and had 5-5.5 gallons in the fermenter, your gravity was right, and either the sample you grabbed was bad (more water than wort), or, the hydrometer itself is bad. Look at your hydrometer, see the temperature it's supposed to read at (it'll usually be 60F or 68F), and take a reading of water at that temperature (+/- a degree or two is close enough, if you're off by more than 5 degrees i'd chill or warm it accordingly). At that temperature, the hydrometer should read 1.000. If it doesn't, your hydrometer is off. If it's reading 1.040ish, then you know it's just flat out broken and needs to be replaced. If it's off a point or two, you can either adjust for it mentally, or there are ways to tweak it. And then going forward, always correlate a hydrometer reading with temperature. Hydromter is only accurate at that reference temperature. Above that it'll read low (a reading of 1.058 at 80 degrees is going to be closer to 1.060-1.061), below it it'll read high (at 1.058 at 50 may be closer to 1.056-1.057). If you're reading at near boiling, it can be off by a huge margin.

So yes, temperature definitely impacts the gravity.

Last question. Are you reading via hydrometer or refractometer? If you're reading both via refractometer, I can tell you exactly what happened. Smaller sample for OG makes it even easier to grab more water than wort. And then after you've pitched yeast and there's alcohol in the solution, refractometer is no longer accurate. Alcohol disrupts the reading.

 

[chawn]

How did you oxygenate your wort? I'd definitely be using O2 for that high of an OG.

 

[Wfu1bunn]

Oxygenated just by shaking carboy as I usually do.

 

[Wfu1bunn]

It was a 5 gal batch. What would I have noticed wrong in trying to hit that OG? I read the gravity with a hydrometer. Can you explain what you say in your last couple of sentences?

By the way, I got the recipe out of a clone recipe book. I believe it is called 200 Clone Beer Recipes. Do you know if those recipes are reliable?

 

[yeahfairly]

Recipe is:
OG was 1045. Would temperature of wort affect OG reading? Wort might have been too warm. Checked gravity the other day and it was 1040. Target OG was 1103-1104 and FG was supposed to be 1022-1024.

It needs to age for about 7 more months(I've bottled it by the way). /QUOTE]

The two things highlighted above would be my most immediate concerns. How long was it in the primary before you bottled?

 

[chawn]

Without enough oxygen in your wort, the yeast cannot multiply the way it needs to. I doubt it could be oxygenated enough by simply shaking it with an OG of 1.103.

 

[Qhrumphf]

It was a 5 gal batch. What would I have noticed wrong in trying to hit that OG? I read the gravity with a hydrometer. Can you explain what you say in your last couple of sentences?

Extract brewing is nearly foolproof. You have a defined amount of sugar in extract that does not change. There can be a touch of variation depending on extract manufacturer and what not, but it's rarely more than a point or two difference.

If you added 10.5 lbs of DME into a 5 gallon batch, your gravity will be very close to right. It is not physically possible for it to be any other way. If your gravity was truly at 1.045, you would either have not added more than half of your extract (which you likely would have noticed), or you would have had to top off to more than a 10 gallon batch, and not 5 gallons. Which you DEFINITELY would have noticed.

So unless one of those two things happened, your OG reading was not accurate. Whether that's a temp issue (if you read the gravity at boiling, it could explain the difference, but that's about it), or your hydrometer is broken (possible) or you simply didn't get adequate mixing of wort and top off water, which is a very common problem with extract beer and nearly impossible to avoid even with extended shaking or mixing. However, it's nothing to worry about, because fermentation will fix it.

My point here is that if you added everything you were supposed to and topped off to where you were supposed to, your OG was right and you can disregard your 1.045 reading because it simply is not correct. For a 5 gallon batch, I would go with 1.105.

And then, for a high gravity beer, not properly aerated for a beer of that gravity (really does need pure O2, can't get to an ideal level with atmospheric air no matter how long or hard you shake it), and without knowing the details of your yeast (you said you made a starter, but starter size, yeast age, etc, I'm willing to bet for a beer of that magnitude you still greatly underpitched), Going from 1.105 to 1.040 isn't ideal, but it makes a little more sense.

 

[Wfu1bunn]

You guys have been very helpful to an obvious new home brewer! One more question....with that high a FG will the beer just be too sweet and not worth drinking?

 

[ArkotRamathorn]

Never tried this before but if the wort was very hot, this could really throw off your hydrometer. The hotter it is, the less dense the liquid would read as. If you measured the wort when it was around 160F and your hydrometer calibrates at 66F your gravity reading could've been off by .020 or more.

Also there's beers in the 1.040 range that are plenty drinkable. Give it time, let it carbonate, if it carbonates a couple volumes higher than you primed for, that will actually reduce the perceived sweetness and mouthfeel. No matter what man, it'll still be beer.

 

[Wfu1bunn]

Yeahfairly, it was in primary for 7 days and secondary for 7 days.

 

[Qhrumphf]

For a beer like that it's not nearly enough time. It more than likely was not done fermenting. I would put your bottles somewhere safe (covered in a plastic bin or something) because if it continues to drop there's a good chance they will explode.

 

[Wfu1bunn]

They have been bottled now for at least 45 days.

 

[PatrickGoss]

I would do some reading about how long to leave brews going. Lots of great info inside HBT. If these bottles are all too sweet for you I would entertain sanitizing them (yes, just dip them in starsan for a minute) and dumping them all onto a yeast cake from another brew, something of a medium OG. Let them hang out on that for a couple of weeks, then rack to secondary for a couple of months, then worry about bottling. A beer that big is going to take a long time. Everyone is right about brewing a beer that big needing some added O2. From where you are at a rough pour onto an active healthy slurry should get you quite a bit more attenuation. Another thing to consider is that the really sweet beers are right up some peoples alley. People sure seem to go nuts over Black Tuesday and it's sweeter than coolaid.