I'm new to this brewing thing but I'm a little puzzled at what's going on. Here's the situation. I brewed up another batch a week ago, today I noticed the airlock had quit bubbling. So I pry off my lid and to take a taste of the brew and a hydrometer reading. First of all, the brew tastes.... strange... it defiantly has a high alcohol content. It tastes so strange I'm not sure if I like it or not. The first thing I noticed after I took of the lid to my fermentor was the smell. I was almost knocked off my feet with the strong alcohol smell and something else that just didn't smell very good. So.... not sure what I should do, I racked to a secondary to get it off that yeast cake. (I was thinking that not-so-good smell was from the yeast eating each other and producing off-flavors.) I put the brew in the secondary about an hour ago. The air lock isn't bubbling, but once every 2 seconds a drop of some liquid forms and drips back down into the brew. I gave this a thought for a second or two and I'm guessing it's alcohol vapors condensing at the top of the airlock and dripping back down.
I brewed this batch with an intention of making a strong beer. I put about 9 lbs of fermentables in the brew.
Does anyone have any thoughts on my situation? I'm mainly curious at to what this liquid is. It's strange how it forms at the top of the fermentor. There is no mist or haze from multiple drops of liquid. It forms in one spot, builds up and drips. It's very consistent, 1 drip every 2 seconds.
It seems as though most people touched upon the original question of this thread, with some other detours along the way.
Seven77, you said that your pitching temperature was 70 degrees F, and some of your temperature readings during fermentation were at times as low as 68 degrees F. I hope my education in civil engineering can help here. There are two ways that could have attributed to the airlock situation. One the pressure of the room (or fridge, or cooler or whatever your fermentation vessel is stored in) is of a higher pressure than the inside of the fermentation vessel, or the pitching temperature inside your fermentation vessel (when you sealed the fermentation vessel) was higher than the temperature at the time that the airlock situation presented itself. You were correct in the fact that you created a vacuum in your fermentation vessel. In either scenario, pressure or temperature differences, you essentially condensed the air in the headspace of your fermentation vessel, and a very low aspect the liquid as well (but its so low in the liquid condensing it is negligible). That is what is causing the liquid in your airlock (you put water, I always put sanitizer to keep a clean seal) to be sucked into the bucket itself. Regardless if you noticed condensation on the bottom of the lid of your fermentation vessel or not, since you are condensing the air in the headspace of the fermentation vessel you are as well condensing the liquid which is in the air of the headspace, this is due to a change in the vapor pressure (the pressure at which gaseous water becomes liquid).
In a lot of situations people, books, and forums suggest pitching at a lower temperature than optimum for the yeast culture to allow the yeast to raise the temperature to be within the range. The yeast culture creates an exothermic reaction, meaning it produces energy in the form of heat and puts into the system it is surrounded by. The added benefit of pitching at a lower temperature is for the fact it allows a more effective lag phase, AKA growth phase, of the yeast. This in turn allows the yeast to create the appropriate by products to have a good healthy fermentation, avoiding production of precursors or actual compounds which contribute to off flavors and off aromas. You can do the opposite, pitch at a slightly higher than optimum temperature which allows the wort to cool further and has generally the same outcome as explained. The down side of this is the negative pressure which pulls the airlock back into the fermentation vessel, although this doesn't happen most of the time because it requires a drastic and large change in temperature. I did not do the calcs for the theoretical number, but I would have to say around 5-8 degrees difference/change in/delta. The reason I pitch over optimum temperature not lower than optimum is because of pure laziness and cheapness. I do not own a wort chiller and do not want to stand forever over top of an ice bath. Generally I have not had an issue with the over temp pitch, but if you are going for quality, and have money on the line, under temp pitch is the way to go.
As for the off flavor and aroma. The flavor is definitely due to green beer. I won't go into too much detail because this can just be found out through experience and tasting, but aging beer is generally good for most beers. Unless of course that style of beer is supposed to be consumed fresh, like hefeweizens or kolchs. But....what I think was the problem of the off aroma of the fermenting beer is CO2. This is something that I tend to forget when I am excited about the beer that I am fermenting and forget to turn my brain on when opening the fermentation vessel. CO2 is not good to breathe, especially in large quantities. I have had a few times over the past 3.5 years to 4 years of home brewing, I open the fermentor and immediately bury my face below the level of the top of the bucket to get that fresh smell, only to realize that it is 100% all CO2, my nostrils burn, I get a slight headache and don't want to open my eyes. CO2 weighs more than oxygen so while fermentation occurs it pushes all the oxygen out through the airlock and leaves behind all the CO2 that the yeast produce during fermentation. So essentially when I do that I am suffocating myself and also breathing in nothing more than CO2...yay me!
