Yeast Adaptation and Starter Size

[maltyPython]

Hi guys, I have had a really weird couple of batches lately...In particular I tried to clone the awesomest beer in the world (pliny the elder what else?!) and I got an OG of 1.075 which is about 10 points lower than I expected! Anyways, I had prepared a 2L stir-plate starter for the 6 Gal. of 1.075 beer (WLP001) and the yeasties were happy and healthy. Also I have used yest nutrient in the wort. Long story short: fermentation does not start for FIVE (5!) days! Probably that happened b/c I kept the temp too low (68F) but the weird part is that on the 5th day fermentation starts hardcore, and it is still going on a strong as ever after 6 days!!! never had anything like this. Any ideas why this may happen?

 

[bja]

I can't answer your question, but 68f is not too low for WLP001. I have 10 gallon fermenting with WLP001 right now at 62f and it took off within 8 hours.

My guess is that your starter wasn't as happy as you thought it was.

 

[kanzimonson]

It must have been an older tube pitched into the starter. I feel like this is something that people ignore or don't think about when they make starters. If you use a really old tube/pack, there are so few viable cells in there that it takes a lot of time to build it up to appropriate levels.

As for your gravity, I believe pliny is within a couple points of 1.075, right?

 

[maltyPython]

kanzimonson: yes Pliny is about 8%ABV which with an 80% attenuation gives an OG of about 1.077. But I wanted more I was shooting for a 9%ABV :rockin:

I did not use a vial. I hold a yeast bank and WLP001 is one of my strains. As I recently recultured WLP001 I wanted to make sure my starter was OK, so decided to take a cell count after the starter was ready. I diluted 1ml of the starter into 9ml of sterile water, for 6 times, and then I plated the dilution: I got MORE than 300 million viable cells in 1ml of stater!!! But that was no surprise to me as I had produced this starter with 8 step ups and a stir plate, so I thought everything was ok.

The only way I think things may have gone wrong is that reculturing the yeast made it mutate, but how likely is that?...sheesh I surely am crossing my fingers for my beer now

 

[bja]

The only way I think things may have gone wrong is that reculturing the yeast made it mutate, but how likely is that?

I guess it depends on how many times it's been recultured, but I've been making and using slants from 8 different strains of yeast that I bought several years ago. I haven't had any issues yet.

 

[maida7]

sheesh I surely am crossing my fingers for my beer now

Yeah, I'd be very worried. 5 days lag time is crazy.

How do you store the yeast in the bank?

 

[maltyPython]

I have recultured the yeast for 2 or 3 times at most...perhaps, last summer I moved and I lost the ability to store the masters in a cold fridge for about 2 weeks. That could have done some damage to my bank. In fact when I got my hands back on my yeast I was ready to throw the whole bank away, but after reculturing I noticed that the colonies were growing just as usual so I took my chances with a couple of batches and everything went fine...till now!

I keep the master culture in water and sugar solution that I keep in the coldest part of my fridge. From that I inoculate slants and every 2/3 months I replace the slants...

 

[maltyPython]

UPDATE: ok now I KNOW there is something very wrong with my yeast. I took a gravity reading the other night, and it was at 1.050 after 4/5 days of active fermentation...

now what?! Just throw in some NEW yeast or throw away the whole thing?

 

[bja]

Is it still fermenting? I certainly wouldn't throw it away. It's only been 5 days, let it go for a couple weeks then check again.

BTW, I've used slants that were over a year old and never had a problem. But I've never heard of keeping yeast in a water and sugar solution. Doesn't sound the the best way.

 

[maltyPython]

The water & sugar solution is recommended by Rajotte in his book. I know some use distilled water with good results but this far I never had a reason to experiment...

bja what do you use for your main masters?

 

[AmandaK]

I use a sterile wort/agar solution for my slants...


Also, I wouldn't throw it away. Keep at it! Keep taking gravity readings, and if it stops, pitch a metric crap ton of HEALTHY yeast.

 

[bja]

I use a glycerol/water solution in the freezer.