Low FG - caused by high ferm temp?

I have done two AG batches in a row that have had a very watery mouthfeel and FG measurements that were very low: 1.004 for one and 1.006 for the other. I am trying to figure out if high fermentation temperatures would cause this. for reference one was an American pale ale and the other was a hefe.

It is possible that my hydrometer is not calibrated but that still does not answer the issue of watery mouthfeel. I should mention that I have not had either of the beers after bottle conditioning, just tasted as I was bottling.

Thank you for your thoughts,
Billy Ray

Did you add water or did you do full boils?

1. Calibrate your hydrometer with distilled water at 60F.

2. How can anyone address the fermentation temp issue if you don't give the temp you fermented at? Crucial detail.

3. Yeast strain? Temp? Mash temp? Grain bill?

4. Carbonation provides a great deal of mouthfeel character. Judging a beer as "thin" before bottle conditioning is foolish.

5. With all that said, an APA finishing at 1.004 is quite low. This suggests one or more errors in your process or the presence of super attenuating wild yeast.

Before jumping to some of these more specific conclusions about your problem, consider the more likely one. Being your second AG brew, were you able to maintain your mash temperatures? If they slumped into the mid 140's you might have ended up with a highly fermentable beer.

What everyone else said, we need more/complete information on recipe, mash, yeast, fermentation temps, etc.

Not only is it possible that your hydrometer isn't properly calibrated, it is possible that your thermometer isn't. If you do feel that mash temperature is the suspect, then realize that mashing too LOW is what would actually give you a more ferementable wort (leaving you with a lower final gravity). I do agree with the others that we need more details about your process to pinpoint the true issue though.

First, thank you for the feedback. Below are details which should help with diagnosing the issue:

American Pale Ale:
7 lbs Pale malt
0.5 lbs Crystal 60L
0.5 Amber malt
0.5 Munich
Mashed for 1 hour at 154, losing 4 degrees in the hour

Hefe:
5 lb 2 row
3.75 lb wheat malt
0.5 munich
0.5 rice hulls
Mashed for 1 hour at 152

I will go ahead and calibrate my hydrometer and check my thermometer as suggested. Any other thoughts on what could be causing the very thin mouthfeel is appreciated. While I understand that you don't get the full mouthfeel prior to carbonation, it still seems much more watery than it should be.

Thanks again,
Billy Ray

You probably aren't losing 4 degrees. You are probably mashing at 150. Give your mash 10 minutes to absorb all the heat then take the temperature. Make sure you are holding your 154 for 60 mins. Also, calibrate your thermomter in boiling water and/or an ice water batch -- if you are at sea level this would be 212* and 32*. Also calibrate your hydrometer. You need to make sure you instruments are working for you and not against you. Lets say your thermometer is reading higher than it should and your hydrometer is reading higher than it should as well -- you are going to be way off on your FG. Judging by your grain bill with the munich and crystal you shouldn't be getting as low as 1.004 for FG

Forgot to confirm that I am doing full boils and my fermentation temperature has been aroudn 75 - 77 degrees.

Of course beer samples had pre carbonation never feel that thick to me either unless they are imperial beers that were mashed high. But again carbonation (or the lack there of) would have no effect on the final gravity reading. Therefore the hydrometer and thermometer off calibration possibilities are the most suspect. Oh and what temperature was your wort sample when you took the gravity reading? Most hydrometers are calibrated at 60F and if your wort sample is not at 60F you need to use a temperature correction chart to "adjust" the gravity reading you get.

I brewed this a few weeks back (Petite Saison). OG was 1.053. FG was 1.003. Had a boil over at beginning of boil which reduced my volume going into the fermenter to about 3 gallons (was supposed to be 5-gallon batch). I didn't top off, just went with it. Mash temp held at 150* F for 60 min. Mashout at 170* F for 10 min. Beersmith says I should have had a 1.009 FG. Why did I have such a low FG? Equipment is working correctly. Was it because there was so much yeast for a reduced amount of fermentables? If so, I should have gotten a lower OG right?

4.50 lb Pilsner (2 Row)
2.75 lb Vienna Malt
0.75 lb Wheat, Torrified
1.00 oz Goldings, East Kent (60 min)
0.25 oz Styrian Goldings (10 min)
0.25 oz Saaz (10 min)
0.75 oz Styrian Goldings (2 min)
0.75 oz Saaz (2 min)
1 Pkgs Belgian Saison (Wyeast Labs #3724)

Nope, 3724 can chew up wort and end that low. You had a low mash temp, so more fermentable wort, no large source of unfermentables like crystal malts or roasted malts, and a yeast that can ferment well if handled correctly. The larger amount of yeast to lower amount of fermentables does not lower FG (though without a starter you likely still slightly underpitched), but underpitching can cause a higher FG.

Billy-Ray said:

Forgot to confirm that I am doing full boils and my fermentation temperature has been aroudn 75 - 77 degrees.

Click to expand...

The high fermentation temperature will keep the yeast working harder, longer, and will contribute to fermenting out to a low F.G. Usually only a few points or so. I would check the Hydrometer calibration point. There are different points for different hydrometers. Some are 60*, some at 68* F. This is a good article on the subject.

http://byo.com/stories/projects-and-equipment/article/indices/29-equipment/414-calibrate-your-hydrometer-and-fermenter-techniques

That being said, Dude you got to get your fermentation temps down. Starting in the low 60* for ales. You will find your beer will improve tremendously. Consider a swamp cooler method, a fermentation chamber build, or just find a cooler place in the basement or something. This is critical for making good beer.