Thursday, April 14, 2011

Yeast on Fire!

I was starting to get worried when the fermentation process for my home brew hadn't started after a couple of hours but, last night, about six hours after pitching it, it finally woke up. Phew! If it hadn't started, I would have gone and purchased a bottle of liquid yeast and pitched that in there, so it wouldn't have been all bad. Below is a video of the airlock spitting away. That's a sign the yeast is eatin'!


Nosh told me how to read the hydrometer, so now I know what the actual original gravity (OG) is. Seeing as I read it while the wort was at 80 degrees Fahrenheit, I will need to calculate it to convert the number to what it would be at the temperature I was supposed to test it at, which is 60 degrees F. The gravity reading shown is about 1.055. To convert it as though it was taken at the right temp, either do the math or open a fancy app, such as the one I use, called Brewzor Calculator. The math is as follows: For every 10 degrees above 60 F, the measurements are off by .002-.003. So, if your brew measures 1.038 at 80 F, you need to add .004-.006 to that. Brewzor Calculator did it for me. My actual reading came out to 1.058, which is .006 higher than what the recipe said it would be. This is ok, that's pretty darn close! This could be because I didn't add quite enough water to replace the water that evaporated, but I still think I did pretty well. I'll take another reading at the 24 hr. since pitching mark today so I can follow what's called the attenuation.

Attenuation is the percentage of sugar (extract) that has converted to alcohol and CO2 by the yeast. This is important if you want to really take great notes and start to understand how to build your own better brew in the future. At least, that's my goal. For now I'll just play scientist and pretend I really understand. The type of yeast strain you choose affects attenuation, which I never really considered before. This, in effect, affects the taste and character of the beer. Most companies will give you the attenuation rates, so I'm going to go check mine. Be right back. Great, the attenuation rate looks like Greek to me. After scouring 326 forum posts about this particular yeast, it looks like the attenuation is perfect for an ale. Most people said the best temperature to ferment at is about 65-68 F. I'll check the temps this afternoon at the 24-hour point. Apparently a dry yeast also takes less time to ferment, so keep that in mind before you reach for the same liquid version. Be back in a few hours with the exciting results!

And that's why your kids should help you brew: Science!

The bubbles are covering the reading, but original gravity is at about 1.055.

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