Recent content by eolle

You never count cells when calculating theoritical maximum extraction from grain. That is for yeast #s not grain yield. The following is a generalization there are some differences from lab to lab and assay to assay but the methods are arbout the same. In the lab they will use something...

Why are people saying the racking early can cause attenuation and or bottle bombs? I rack when the krausen falls back and usually 2/3 of the sugar has fermented. I have not had a early attenuating beer or bottle bombs (when I bottle conditioning). The majority of the fermentation occurs...

Thought I'd clarify a bit to help out its really not that bad to manage. BeeGee is on the right track. I'll give a little more detail of what I do. Mash in (1.25 to 1.4:1 is good for decoction) target between 120 and 128 (122 for lager and 128 for a doppleweisen bock similar to Aventinus)...

Yeah and grain density...but there is one problem with shallow. Without enough overall resistance you can cause channeling. It is very easy to channel a shallow grain bed if you draw off too fast. A larger grain bed provides greater resistance (which slows run off) but also acts to "even out"...

It will work fine! Good job with the flaming of the bottles and the use of 151. A posibly less expensive alternative would be 70% rubbing alchol but you cant drink it :). To increase viability it is better to put yeast in to a quiescent state when in the log phase (i.e. active growth). If...

Hmm...enzyme kinetics are independent of the vessel size and shape. It is dependent on the concentration of substrate and the enzyme. 15 min mashes are possible in any shape cooler there is a vast excess of enzymes in todays grains. I've seen full conversion via iodine test in 15 minutes or...

Don't worry. It takes a couple of times to work out how much sparge water you are going to need. Generally, depending on what you want for mash consistency....I mash in with between 4 to 5 gal of water. I start about 10-11 gal of sparge water. When I get a little more 13 gal (90 min boil) I...

FWIW. Doubling time and fermentation rates are not the same thing. The doubling time is how long it take the yeast to divide. Fermentation rate is how long it take the yeast to convert a sugar molecule into ethanol and CO2. In a simple system...doubling the number of yeast would cut the...

I do it all the time. I usually only save 50 ml but a 12 oz bottle would be more than enough. If they settle out...you can pour off most of the liquid resuspend the yeast and dump into a fresh starter. No problems at all! Just make sure you use good sterile/aseptic technique. If you did a...

1. Most trub doesn't matter that much...after 1 batch. Okay that isn't 100% true. Trub matters a little but not so so much that you should have to worry about it. In fact I can think of about 5 different microbrews that do serial beers (usually 3 or more batches). So the do 1 beer and pitch...

You have a couple of options. First you can brew it like a lager. Pitch the yeast and wait for good activity and then throw in a temp controlled area I usually set the low end a 50. For primary there is no real reason to slowly step down. After at least 2/3 of the OG is feremented then do...

Its unlikely the beer has expired. Sounds like some form of contamination. If you pop the cap does it foam out the top? Also if you smell it does it have a weird chemical type smell? If so it sounds like you've got a contamination that could have occured anywhere in the brewing process...

I'm a scientist and I can tell you that ice DOES kill yeast no if and or butts about it. Its not as effective as an autoclave, boiling, bleach ect but it will kill yeast and bacteria. More specifically the formation of ice crystals around/in the cell membrane is the main culpret for cell death...

Right on! It doesn't really matter what sparging method you use (batch v. continous) or even the water temp that much all that really matters is that you have enough voulume in your boil. I've seen everything done and almost everytime it makes good beer. Don't worry too much. I can dig...

Decoction mashing will work fine with a cooler set up. I've done them before. A single decoction is more than enough and I couldn't detect a major differnce between a single, double or triple decoction except for time. One problem I've seen with decoctions is the grain bed being way too dense...