Slanting yeast - Page 2

gingerdawg · 08-21-2009, 04:11 PM

Quote:

Originally Posted by Saccharomyces;1498692[I

Grab a slant, unscrew the cap, and place it on the foil (open side down). Keeping the slant near the flame as you work, grab the paper clip and remove it from the sanitizer. Run it through the flame a few times to sterilize it, and dip it back in the sanitizer to cool it off. Now dip the clip into the yeast package, and then into the slant 4-5 times. Drop the clip back into the sanitizer to free up your hand, and screw the cap on. Sit the vial to the side. Repeat for the remaining vials.

When you dip the paper clip into the slant, are you jabbing it into the agar? or rubbing it along the slanted surface?

ChillyP · 08-21-2009, 04:51 PM

Finally been waiting to a tutorial. And Subscribe.

**Saccharomyces** · 08-21-2009, 05:44 PM

Quote:

Originally Posted by gingerdawg

When you dip the paper clip into the slant, are you jabbing it into the agar? or rubbing it along the slanted surface?

I jab it into the slant but not all the way to the bottom. Streaks of yeast will grow everywhere the clip has touched, each a colony from only a few cells.

saq · 08-21-2009, 10:50 PM

Thread Prosted!

**Pappers_** · 08-21-2009, 11:22 PM

Thanks very much! This is fantabulous!

Now, there is a war in my brain - one side going "cool" and the saying "what a pain in the tuckus."

jason.mundy · 08-24-2009, 02:00 AM

Quote:

- Vials. I use the 24mL vials from Cynmar, stock no. 115-27910.
- Beakers. I purchased the set from Cynmar, stock no. 115-20035.

Good post! This is motivating me to slant my yeast.

Thanks for the part numbers and the reference to www.cynmar.com.

I have a lot of this stuff already. I may be able to do a few equipment substitutions.

Pyrex beaker could be replaced with a pyrex measuring cup.

A candle could be replaced with a propane torch I bought to sweat copper fittings.

KopyKat · 08-24-2009, 03:41 AM

Quote:

Being careful not to drop in the stir bar

I use a stack of 10 3/8" earth magnets to move my stir bars in and out of a flask. They are strong enough to grab the bar through the glass and slide it in or out without any dropping. They are handy for other things as well.

Rare-Earth Circular Magnets - Lee Valley Tools

**humann_brewing** · 08-31-2009, 05:34 PM

Thank you for this. I tried using some WLP830 that I washed almost 7 months ago and had no luck. So this is my next step.

EricCSU · 09-03-2009, 08:15 PM

How many cells are typically in each slant?

**Saccharomyces** · 09-03-2009, 08:44 PM

There is enough yeast that a 250mL starter is actively fermenting on the stir plate after 24 hours. Assuming a growth rate of one generation every two hours, and a maximum yeast concentration of 80M cells per mL, there would have to be at least 5M cells in the slant. So a conservative estimate would be somewhere around 1M ~ 10M cells... but it's just a guess.

This is the best online resource IMO regarding yeast cell concentration and growth rates in wort:

http://www.maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices

If you read, you will see why I use a stir plate AND sterile wort for the first step; the method he gives you can use non-sterile wort safely but it requires adding 10mL of wort (which you could add directly to the slant vial) and wait 2-3 days before pitching the 250mL starter. Since I use sterile wort and am very very careful with my sanitation in the first step, I go straight from the slant into 250mL without any problems.