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Alright, I have some results from my experimentation with freezing conditions. Cells were grown up in a starter until they reached stationary phase. They were then kept in the refrigerator for a few days. I aliquoted 30 billion cells into 9 different 50ml conical tubes, centrifuged them, and...

The continuous aeration idea came from the guy at Wyeast that I spoke with. I used an aquarium pump with an inline 0.2 micron filter and no diffusing stone, just blowing bubbles into the wort. I don't know if an air stone would help or not, probably not if you're using a stir plate. I did use...

So my problem was a lack of oxygen in my cultures. I used an aquarium pump to do continuous aeration in addition to infusing pure oxygen at the start, and I got really nice growth. I started with 5 billion cells in 1L and they grew up to 70 billion in 12 hrs. I then removed the supernatant and...

I just spoke with the microbiologist from Wyeast on the phone. Very helpful guy. He gave me some tips that I'll try to implement this weekend. He told me their pitch rate calculator is only for very rough estimates, and that actual numbers will vary a lot based on strain and equipment. I'll...

I'm using this yeast nutrient from Wyeast. http://www.rebelbrewer.com/shoppingcart/products/Wyeast-Beer-Nutrient-%252d-1.5oz.html Their website says that's all that's needed for starters. Do you think I should be using something else?

I started off keeping it at room temp (~72oF), then I moved it to 30oC (86oF) to speed up the growth. I don't think that matters much because I had poor growth at both temps. I oxygenate every batch of fresh wort before I add it. I've been adding between 1.2-1.5L of wort. I'm up to ~250...

My yeast is growing really slowly. Anyone have any suggestions? I made my starter with 1.5L of bottled spring water (not distilled) + 150g light Munton's light DME from Rebel Brewer. I added 1/2 Tsp of Wyeast yeast nutrient, boiled x 20 min, cooled to room temp, oxygenated using BernzOmatic...

Thanks for the detailed explanation. I think I understand where you're getting your numbers from, but just to make sure I'm doing it correctly... Using the Mr. Malty calculator, if I enter 1.223 for the OG, 5L, and 50% viability, stir plate, it tells me I need a 1.4L starter (which is what I...

Can you give me links to those calculators. The ones I've seen are pitch-rate calculators that tell you how many cells you need depending on the beer your making, but I can't find a calculator that gives you predictions of growth rates and numbers based on starting cell number and volume of...

Oops that was a typo. I corrected the post. The OG was 1.040

I agree. I was expecting more cells. I weighed out 150 grams of light DME and added 1.5L of water and 1/2 Tsp of yeast nutrient. Boiled for 20 min, cooled to room temp. The original gravity was 1.040 just like I read it should be. I oxygenated using a can of pure oxygen and a diffusing stone...

The vial from White Labs was ~50 billion (depending on how you count), which grew up to 115 billion in the 1.4L starter. Don't try to factor in time for the growth rate on my starter. I had it at room temp, but then cold crashed it for a few hours thinking it was done, but then I put it back...

As far as microscopes, I don't know, but this one looks pretty good: http://www.amazon.com/dp/B005TJ5CEG/?tag=skimlinks_replacement-20 I'd consider this one if you want a cheaper alternative though: http://www.amazon.com/dp/B000NOU54O/?tag=skimlinks_replacement-20 If you end up getting one...

OK, so my colonies have grown up so I can compare counting on a hemocytomter with CFU by plating. I want to revise my previous calculation based on hemocytomter counts to say that the original vial had 66 billion yeast. The CFU on the plates say there were 44 billion. It's pretty close, but...

I first counted at home using the $24 microscope from Amazon, then I took the cells into work to count using a real microscope. I was able to get pretty close using the $24 scope, but it was pretty difficult, and I have many years of experience counting cells on microscopes. There's no way you...

Well, the experiment has begun. I made my starter last night. I decided to use California Ale yeast from White Labs (WLP001). Before pitching the yeast, I took out a small aliquot to count on a microscope and hemocytomter, and measured viability by Trypan Blue exclusion. The total # of...

I agree colony forming units (CFU) is the most accurate way to measure viability. The problem is that it takes 24-48 hrs for colonies to grow up. Meanwhile, what do you do with your starter? It'd be nice to have a real time measurement of viability. As far as I can find, no one has directly...

I use trypan blue to measure viability, but I don't know where you can buy it other than scientific supply stores like Sigma-Aldrich. I don't know if they'll sell to an individual user not affiliated with an organization. I think you can also use methylene blue, which you may have an easier...

I bought a $24 microscope on Amazon. To be sure, you get what you pay for, but it's actually good enough to focus in on a hemocytometer. I haven't tried counting yeast yet, but I think it'll work OK. http://www.amazon.com/dp/B0001FPRC0/?tag=skimlinks_replacement-20

Have you had any results Katy_bug?