First Slant Questions (Pic included)

[mthelm85]

Below is a picture of my first innoculated slant alongside a blank slant. Will the yeast continue to grow or do you think it's safe to tighten the cap all of the way down and store in the fridge? It looks nice and healthy to me, no off colors, just a nice milky layer on the surface and in some spots it looks like it is even growing down into the malt-agar medium.

 

[theredben]

You will be fine storing the slant in the fridge at this point.

Is there a reason you streaked the entire surface of the media? Usually you would just streak a thin zig-zag pattern down the centre so that you could see the edge of the yeast growth. In general, cultures cannot be considered "clean" if you cannot see the edge of the growth.

 

[mthelm85]

You will be fine storing the slant in the fridge at this point.

Is there a reason you streaked the entire surface of the media? Usually you would just streak a thin zig-zag pattern down the centre so that you could see the edge of the yeast growth. In general, cultures cannot be considered "clean" if you cannot see the edge of the growth.

I did not know that, will do next time. I did streak in a zig-zag pattern but I did it three times because I couldn't see how much of the slurry from the smack pack was actually on the surface. Now I know one pass is sufficient!

 

[Flakk]

Just because you can see an edge to the yeast growth on an agar slant does not mean you have a pure culture. To be certain you would need to streak out a bit from the slant onto a larger plate in order to get isolated colonies.

Keep an eye out for fuzz or spots of variable color in your culture that might indicate contamination. Also remember that you only need to streak a tiny amount of yeast to start/transfer a culture.

 

[mthelm85]

Just because you can see an edge to the yeast growth on an agar slant does not mean you have a pure culture. To be certain you would need to streak out a bit from the slant onto a larger plate in order to get isolated colonies.

Keep an eye out for fuzz or spots of variable color in your culture that might indicate contamination. Also remember that you only need to streak a tiny amount of yeast to start/transfer a culture.

Thanks for the advice. There is no discoloration, inconsistency in texture, etc., with this slant. It's just a uniformly milky white layer so I think I'm good to go.

This one won't even be used, I was just doing it as an experiment. I really just wanted to try it out and I do want to get a bank of limited release yeasts going so that I can have them year-round and trade with others.

I'd be too paranoid to use slanted yeast on a whole batch when I can buy a smack pack for $7 and know that it's safe, unless it's some kind of limited release yeast that I can't get when I want it.

 

[theredben]

mthelm85, if you can trust your yeast propagation technique on a "special" beer, you can trust if for a "regular beer". People on this board (including myself) have sucessfully fermented beer from their yeast slants repeatedly. If you are too paranoid, then you just need to practice with some small starters until you feel more comfortable.