Can't get below 1.040 FG

[chichum]

I have been making beers for about 2 years now as a hobby. I've been adding more and more equipment to my collection and trying to get better at it. No matter what I do, I cannot get a beer below 1.040 FG. This includes all types of beers, Belgian Tripels, Quads, Imperial Stouts, Imperial IPAs, hefes, everything. I will get the same results if I just dump the yeast in or if I make a 2L starter. I've doubled the amount of yeast (purchased multiple vials). I bought an O2 tank and use that to aerate the beer. I'm lost. Every beer ends up around 1.040, regardless if it started with a 1.110 SG or a 1.060.

What am I doing wrong? What can I try to fix this? It's really annoying and I'm out of ideas.

Thanks!

 

[crispbrew]

First all what are you using to measure the final gravity? A hydrometer or refractometer? If a hydrometer check to see what it reads in tap water to ensure it reads 1.000. If a refractometer, they are not able to read true fg as alcohol messes with the reading.

 

[soupfist]

The range you're quoting there of 1.060-1.110 SG is pretty heavy even at the low end. Not every yeast strain can handle what inevitably becomes the high alcohol content in your wort. Check that the yeast you're using can handle that high a gravity. Also, have you tried adding yeast nutrient?

Obligatory dumb question: are you sure about your measurements? You may have a lousy hydrometer...

 

[chichum]

Thanks for the replies. I add yeast nutrient to every batch and to every starter. So yes to that. I'm using a refractometer. I was unaware that the alcohol messes with it. I just stopped using my hydrometer when I got that. I'll do a quick test to see.

 

[DonH]

Thanks for the replies. I add yeast nutrient to every batch and to every starter. So yes to that. I'm using a refractometer. I was unaware that the alcohol messes with it. I just stopped using my hydrometer when I got that. I'll do a quick test to see.

There you go! No refractometer once alcohol is present!

 

[Yooper]

Thanks for the replies. I add yeast nutrient to every batch and to every starter. So yes to that. I'm using a refractometer. I was unaware that the alcohol messes with it. I just stopped using my hydrometer when I got that. I'll do a quick test to see.

Aha! Use a hydrometer once alcohol is in the mix, and you'll find that the readings are accurate.

There are calculators out there that are somewhat accurate for guestimating the FG from a refractometer reading (Sean Terrell's is recommended), but it's not be exactly accurate for me. I always use a hydrometer post fermentation, even for wine.

 

[RmikeVT]

Please tell me you haven't been dumping the beer!?

You need to make an alcohol correction when using a refractometer. Here is a tool that does the correction for you, you just plug in the numbers.

http://www.brewersfriend.com/refractometer-calculator/

 

[pfgonzo]

I love posts like this. Where someone is worried or frustrated, but it turns out that all is glorious!

Assuming the issue was the non-corrected refractometer, of course.

 

[chichum]

One more question for those professionals: how do you account for added alcohol when taking the gravity of a beer? Usually when you do bourbon stouts/tripels/etc. you're adding bourbon to cubes and adding to the secondary. Most of the time it's not that much to make a significant difference but I've seen recipes that call for 1/2-1 cup of liquor for a 5-6 gallon batch. I'd imagine that has to do something to the alcohol content of the beer. Does a hydrometer account for this?

 

[pfgonzo]

No. The hydrometer is only good for the before and after fermentation calculation. Everything else has to be done by hand. Estimating the increase in alcohol from the addition of 1cup (8oz) of a spirit is doable though.

Let's say you have 5 gallons of a 6% beer. (Let's assume you've already done the pre and post gravity readings to get that 6% number.)

5 gallons = 640oz
640oz x 0.06 = 38.4oz of ethanol
+8oz of an 80proof spirit (40%) = an additional 3.2oz of ethanol.

You now have 648oz of liquid, of which 41.6oz are ethanol. The % per batch at that point is ~6.42%.

(Note: I've never logicked that out before. Someone please feel free to mention if I missed something)

 

[PrinceOfThePoint]

Measuring gravity wrong for two years?!? Jk... Surely you can tell whether or not they really are at 1.040 by the sickening sweetness...??

 

[Bobbybob]

A hydrometer will get your sg for fermentation but adding after gets a little funny because you are also adding volume.

 

[Smellyglove]

Don't stop using your refractometer. You can use it to determine if you've reached FG if you get the same readings with some days apart (even though they are bogus, but it doesn't matter as long as they are the same). When you've concluded the FG has been reached then you pull out the hydro to find out what the FG really is.

 

[chichum]

I've only been using the refractometer for about 6 months. So prior to that I must have been getting proper readings. The beers aren't sweet at all (unless of course I wanted them to be) which is what threw me. It didn't seem right I was getting such high readings.

Thanks to all for the assistance. I'm bottling this weekend so I should know how off my readings are.

 

[cmoewes]

The calculators for the refractometer are pretty good. You need to know your OG and the current brix reading from the refractometer and then you get the adjusted gravity. I use the one in BeerSmith but there are online ones.

When I put my beer into primary I pre-calculate what the adjusted gravity=> to brix is and put that on the label I put on the fermentor. That way I can take my sample check it and I already know what the adjusted measure should be. Then when I'm sure I'm steady and close based on the refractometer I use my hydrometer to get a final more accurate reading.