Yeast Starter?

Just wondering has anyone ever tried to take dormant yeast off of a beer.
I have done this and put it into a food saver bag and pulse vac and sealed it. I have used washed yeast before, but i didn't wash this just poured it from carboy to bag and sealed it. Put it in my secondary fridge which has no light emitting into it.
This came off a cream ale which is lightly hopped and the og was around 1.052.

When making my next batch I will take wort off that and put it in a mason jar and cool it down and pitch this into it and replace the lid quick starter style. So by the end of the process, it should be like a slap pack. Doesnt hurt to try right?

I will do 2.5 gallon batches one with new yeast from the store, one with this yeast. I will keep you posted.

I don't see that being much different than putting it into a mason jar. I would bet it will have about the same shelf life.

I have tried the jar method, it didnt seal. Plus you have to stick it in boiling water to perform a canning method on the yeast to prevent botulism.

I use ball canning jars and have never had a problem with a seal. I don't understand why you would need to boil to decant?