Slow down a bit. You harvested yeast from a commercial beer and brewed with it? Can you tell em how did you do it?
Interestingly, I did the same last year with yeast from a Chimay Abbey Ale (750 ml) bottle, but I tried twice with Ommegang and also with Duvel 750s (same parent company, Moortgat), and couldn't duplicate it - I think they use a different yeast to bottle than they do in primary.
On the Chimay, the cork indicated 2017, so the yeast was a couple of years old and in the bottle. My procedure was to (of course) pour off all the beer, and enjoy it! But immediately have ready a fairly small and relatively weak starter - something like 100 ml of 1.010. Instead of transferring the yeast out of the 750, I added the boiled wort to the bottle (figuring the bottle was plenty sanitized after being two+ years sealed). I used a rubber balloon instead of an air lock during the early stages. I swirled the bottle every now and then and kept the temp up at around 70 - 72 F (21 - 22 C). After the balloon inflated (may have taken more than 24 hours), I went to the next step, which was to add a slightly bigger qty of wort (150 ml) at a slightly higher gravity - like 1.015. May have done one more step in the bottle (repeating with slightly more wort, slightly higher gravity) before transferring to a larger starter vessel, but the idea is to gradually work the yeast cells up until you have something close to what you'd buy from White labs or Wyeast.
When the volume in the bottle was more than half, I started working with larger vessels and eventually worked up a pitchable quantity for a 3.5 gal batch (initial batch sizes for my first all-grain batches), but you could continue to build for a 5 gal or 10 gal batch size.
I'll say it was a one-of-a-kind batch. I really felt fully vested in the outcome, since I raised these yeast from a few million dormant cells to a few hundred billion active cells. The beer had an extremely nice Belgian-style taste profile, and I drank them faster than intended. I hope to try this again this year, and wish you good luck in trying to do the same.