Getting Low Finishing Gravities

mangine77 · 01-13-2009, 01:23 AM

Please help me figure this one out. I'm still pretty new at all grain. I've done 6 beers AG. I'm hitting my OG pretty right on, but then after fermentation my beers are drying way out and finishing SUPER low.

I know it's hard without knowing my process, but what is the most likely cause? Example: My last brew OG was supposed to be 1.052 and I hit 1.050. FG was supposed to be 1.012 and mine was 1.004. Why did it finish so low?

This has happened for my last 3 brews. My buddy that knows a lot about brewing says he would bet it's a faulty thermometer. He thinks I'm missing my mash temperatures by quite a bit. Does this make sense to you?

I have definitely questioned the accuracy of my dial thermometer. I just bought a lab grade thermometer and I plan on using it for the first time this weekend.

What is the most likely cause of this problem because it has become consistent? I'm missing my FG by around 10 points each time. The beers have come out tasting good, just not finishing within style.

**Yooper** · 01-13-2009, 01:26 AM

I've had the same issues. Generally, it's because of mash temperatures. In my case, I never did figure it out. Check the mash temperature, and make sure your thermometer is accurate. Are you using a very attenuative yeast strain?

steelerguy · 01-13-2009, 03:21 AM

Before I even got to the part where you buddy said the thermometer I was going to say thermometer. I have had some jacked thermometers, my first two analog ones in fact. They would read way high for both freezing and boiling water.

Finally got a digital thermometer that could also be calibrated. Came with a degree on both freezing and boilding water so I didn't even bother with the calibration. Last two batches with the thermometer finished right on and didn't dry out. I figure I was mashing in the mid 140's when I thought I was 152-154.

guevedoche · 01-13-2009, 03:50 AM

Absent your process details we're really just guessing, but that's probably the only reason I'm comfortable offering an opinion.

Are you doing a mashout or starting the 1st runnings in the boil pot soon after collection? If the wort is sitting at 140-150 F for an extended period (e.g., while waiting for batch sparges to complete) without first denaturing the enzymes via mashout/heating, you will end up with a more fermentable wort.

+1 on the thermometer is your best friend and your worst enemy