old yeast as nutrient

[Chad Keven]

Does anyone use old yeast as nutrient for culturing? I am culturing the dreggs of a bottle of Fullers bottle conditioned IPA, when preparing a small 500ml starter I boiled about 50ml of old yeast (strain unknown) from the fridge for around 10min, the starter is pumping after 2 days, my problem is; have i contaminated what Im trying to grow? is 10 min boiling enough to kill/break down the nutrient yeast?

Im a bit surprised and suspicious of how well its taken off, any thoughts appreciated, and merry xmas

[JR]

I really think that even 1 minute of boiling would kill em all.  Be interesting to compare what you culture out of that bottle with some WY1968 (which is the fullers yeast) and see if there was much difference in a yeast that has been recovered from the bottle.

[Ralph]

Do you know if fullers bottle condition with a different yeast to what they ferment with? It may not be WY1968 strain anyway.

[Chad Keven]

sweet thanks for that

[Damon Colbert]

Should've been well nuked after 10min boiling, that's all it would take me to kill a yeast at work.  Was there a distinct colour change from beige/cream to grey?  That's a good indication of cell lysis.

[Chad Keven]

yes both changes in colour and the appearance in the bottom of the flask much more lumpy and broken down looking