I think you only risk damage to the yeast if you store them for a long time at warm temps after you make the starter. Make the starter and pitch it while it is active or chill it in the fridge when activity starts to subside. You don't want them sitting at warm temps with nothing to eat or they will start eating each other.
I agree. You don't want to leave the yeast sitting warm because they end up using their glycogen reserves. The reserve is what they use when they first hit the wort and get themselves ready.
I've been doing a bunch of experiments and speaking with both Wyeast and White Labs over the past few months about starters.
One tube or smack pack into 2 liters of wort will approximately double the amount of yeast.
One tube or pack into 1 liter will increase the yeast by about 50%.
Those numbers are for starters with initial O2 around 8 ppm. If you shake the starter every hour or put it on a stir plate, you'll get about 2 to 3 times as much yeast.
On the hemocytometer, do a lot of practice runs first. It is possible to get results that are 200% or more off the mark. Proper dilution and counting method is key.
I hope my post helped in some way. If not, please feel free to contact me.
jamilz wrote:On the hemocytometer, do a lot of practice runs first. It is possible to get results that are 200% or more off the mark. Proper dilution and counting method is key.
Four step serial dilution seems to be the best way. Also using both troughs in the hemacytomer with different counting methods will yeild more acurate results.
Since I got the microscope, I got diverted doing RBC counts. My arm looks like a junkies from making smears.
It really depends on what sample you're starting with. Eventually, you can just look at the sample to see how cloudy it is and decide if you need to dilute more or not.
Hey, the heroin needles are for taking refractometer samples.
I hope my post helped in some way. If not, please feel free to contact me.
There is one technique that I come across a lot in German home brewing, the use of the first wort to wake up the yeast. The idea is that the first wort is the ideal medium to wake up the yeast with since it's composition of sugars matches that of the cast out wort. You take about 200 - 300ml of your first wort. dillute it to 500ml and boil it for 10 min. Then you chill it to pitching temp, should go quick, and you pitch the yeast. In case you are doing fly sparging and a 90 min boil, the yeast got a 3hr head start.
I haven't tried this myself since I batch sparge (not so much of a head start) and am propagating yeast anyway.
The particular advantages of this method is that you don't need extra wort (or DME) ahead of time and that you give the yeast a head start. But it cannot be used to validate the yeast viability (since you are already committed to brewing this batch) and it is just another thing to do in a sometimes already busy brew day.
While we are talking yeast and starters, could you guys have a look at my idea for growing starters http://www.thebrewingnetwork.com/phpBB2/viewtopic.php?t=2734 and tell me what you think. Sorry about cross posting and then advertising it, but this seems to be thge current yeast/starter discussion, but my post is equipment related so I put it in the Eq section.
