Hey Everyone, This has happened on my lat few batches of all different types, but we will use this last batch as an example. The batches fermentation ends way early. They start with a decent OG, then finish fermenting at a FG that is about half the way to what it should be. Brewing a very simple wheat beer: 5 pounds 2-row 5 pounds white wheat .5 oz Hallertau (once at 60min, once at 30min) Basic process: My mash tun is just a beercooler with a filter near the release valve it tends to hold temperature ok. Held all the grains in the mash tun at 154 degrees for 75 minutes. Boiled for 60 minutes then pitched a vial of WPL300 that i had started 18 hours before. OG: 1.044 1W: 1.036 2W: 1.026 3W: 1.024 Does anyone have any idea of what could be restricting my fermentation? Any tips would help a whole lot.
Its pretty stable, it just sits in our kitchen pantry. Thermometer in there looks like 75-76 degrees.
Have you checked your thermometer? If it is off you might be mashing higher than you think. Although, you'd have to mash pretty damn high to only hit 44% attenuation.
Agreed with what's said above. Try your thermometer at boiling to see if it's accurate. Or hell go to the grocery store or Target and buy a new one.
You know that sounds like it could be the problem. When I have the thermometer in the boiling pot it only registers like 190-200 when it should be up around 205-210. So the mash temperature being too high can really affect my fermentation?
High mash temp can totally affect FG. The higher the mash temp, the less fermentable sugars arise from the mash. If your thermometer is off by 5-10 degrees and you're mashIng at "154", you're really mashing at 160 or so which will yield a much less fermentable wort causing your FG to be higher than what you really want.
DNuggs - This sounds like it could definitely be my problem. If I am mashing at a too high of a temp, would this also yield normal OG numbers while making the wort less fermentable? Jthahn - I'm using a regular floating hydrometer to measure my gravity. As far as i know it has shown reliably, I can tell my beer has not fermented fully because it taste fairly grainy and sweet.
FWIW, boiling water should always register 212*F, unless you are at a very high altitude. I bring a quart of water to a boil first thing ever brew day, and calibrate my thermometer. Then that water goes into my mash tun to pre heat it. Kills two birds with one stone.
Possibly Definitely. So you're about 12-22 degrees off, which is huge. Also, what do you mean it registers 'like 190-200'? I've never seen a thermometer swing that widely at a single stable temp. Did you actually read it, or are you guessing?
