Gravity problems

[mafeeker]

So, recently I have been coming in lower on my FG than expected by usually five or so points. I thought it was my mash temperatures, so i bought a new thermometer. I just checked the gravity today on two beers brewed with the new thermometer, and the problem is still happening. My question is can overpitching cause this to happen. I usually pitch a 2 liter starter for all my ales, and i oxygenate my starters. Anyone have any advice/experience with this problem?

 

[martinworswick]

what were the original gravities?what fg were you anticipating? are you using a hydrometer or refractometer? what temp were you taking the reading at?, have you tested your refractometer/hydrometer with distilled water?

 

[mafeeker]

OG: between 1.040 and 1.060 expected FG: 1.012 and 1.018
Beer tested today: OG 1.042 FG: 1.006
Samples tested at 68 degrees
Using hydrometer, tested in tap water and was close to 1.000

 

[mafeeker]

beer tested today: anticipated gravity: 1.012

 

[martinworswick]

have you tasted the beer? tastes normal? what strain of yeast were you using? what was your mash temp?

 

[Calder]

Lower mash temperatures = lower FG.
Longer mashes = lower FG.
Different yeasts have different attenuation rates.
Use of simple sugars = lower FG.
Re-using yeasts tends to result in lower FGs.

Personally I try hard to get beers to attenuate well. I re-use a lot of yeast and record the attenuation I get with them, and often design my beers with this in mind.

 

[mafeeker]

My mash temps were generally 150 - 152, but there have been some brews i do that had 154 mashes and they still attenuated a lot. The beer tastes fine, its not infected, but some of them lack body. For example, my maibock and scottish ale both would be a lot better with a fuller body. My mashes are usually 60 min, and i use 1.5 qt per gallon. The yeasts were all from wyeast activator packages and then pitched into a 2L starter. There have been a variety of strains: German lager, scottish ale, london ale, german/kolsch ale

 

[mafeeker]

For example, my liberty ale clone had an expected FG of 1.013 and used wyeast american ale 2L starter. The OG was 1.055 and it attenuated down to 1.002. It tastes fine, there wasnt any infection or anything like that, but this is kind of frustrating. Should I just get a laboratory mercury thermometer or something?

 

[mafeeker]

From what I have been reading, it might be because I fly sparge, and this usually takes about an hour. That would mean that an hour mash is really more like 2 hours because of the lengthy sparge time, which would make a more fermentable wort. I guess I am going to start performing mashouts to preserve the sugar profile and invest in a few more thermometers.