FG on Big Beers

[MadHopper26]

I've been brewing for eight years, all-grain for five, and this is the first time I've ever consulted with anyone. I'm not in a homebrew club, and none of my friends brew, so I've pretty much been on my own, though I've visited this forum regularly. I've finally come across one confounding curiosity though, and I just can't find any info on it.

About a year and a half ago, I decided to start brewing some high gravity beers. My initial instinct was just to crank up the grain volume, which I did, and hope for the best. I've done four beers, all between 100 and 120 OG. All of them taste awesome and I haven't had any fermentation problems to say the least. Here's the thing though, they've all come in under 1.005 final gravity. Does this make any sense?

First of all, I've been using big starters... three quarts for four-gallon batches, White Labs California or Belgian Strong Ale, and decanted before pitching. I've also used double the normal nutrients and a lot of aeration. Is it normal to get so low on such big beers? Is it just the low SG of all the alcohol pulling it down? The attenuation is just crazy.

I'm 100% certain about my measurements. I use both a hydrometer and a refractometer. I'm a process control engineer by trade, and these instruments are calibrated and accurate. The numbers are what they are. All that having been said though, the beers are great and they don't taste or feel thin. In fact, the seem to have a good body.

Any thoughts? Thanks!

 

[dale1038]

I guess my first thought would be what temp are you mashing at? Sure seems hard to get that low with 001. Not out of the realm of possibility with Belgian though.

 

[MadHopper26]

Hi Dale,

I thought that two. With my first one, I was concerned about leaving it too high, so I mashed around 148. When it came out so low, I tried 152, and it honestly didn't make much of a difference. It went from 002 to 004. I'm glad to hear somebody say this isn't out of the realm of possibility though.

 

[dale1038]

I mean, its definitely really low. Somebody will chime in here in a minute and set us straight on what's going on.

 

[aberry]

Do you use sugar?

 

[Paul07293]

What's your grain bill? You didn't mention a style. That's an awesome finishing gravity for Belgian Golden Strong or Trippel but not so much for a Russian Imperial Stout.

 

[MadHopper26]

No sugar except on the first one. I learned my lesson. Actually, all but one were Belgians, so I guess it does work out. My last one was an IPA with a good amount of Crystal, so I'm really perplexed by that one (it's sitting at 005). One thing that occurred to me in reading these responses is that my thermometer may be off. It's the one thing I'm not sure of. Maybe I have been mashing low. I'll check that. At any rate, my wife and I are the only two who drink my beer, and we're thrilled with all three of the big ones so far (the fourth is in the secondary now). So I guess that's all that matters. It's just a weird situation that I thought I could use some input on. Thanks for the feedback!

 

[guideaux]

My F/G's are very similar. I have noticed all of my beers get low F/G's. I have a Winter Warmer, OG 1.066 in my secondary at 1.009. The FG's you record are crazy, but I always attenuate more than the recipe would call for.

 

[GuldTuborg]

AAs above 95% are not unheard of in the realm of commercial beers, but generally not without sugar additions, and never (that I've seen) at this kind of gravity. I would guess there's an error in measurement somewhere, but I could be wrong. Do these beers taste very thin or highly alcoholic? What kind of hopping do you use on them, generally?

 

[karljrberno]

I made a skull splitter that went from .076 to .005 i like the "Thin" Tast

 

[wonderbread23]

My guess ... wild yeast. 1.120 to 1.005 is pretty extreme for normal sacchromyces. In order to that kind of attenuation you'd need to mash very low, include lots of simple sugar, use lots of O2, use massive pitches, ferment warm, etc.