Under Pressure - preparing flasks

I am continuing to collect equipment and supplies for my Orchid Flasking adventure and have taken another couple of steps closer to success.  A key component of that success will be sterility, and a key tool for that is an autoclave.

Mine was actually designed as a home pressure canner for preserving food (a giant pressure cooker), but that process has the same end in mind: a final product completely free of bacterial and fungal contamination.  As long as it can sustain at least 15 psi of pressure and 250° F it will accomplish that.  In my mad-scientist way, I rather enjoy the anthropomorphic thought of contaminating organisms landing in the freshly made nutrient media and "thinking" they have hit the jackpot, only to be utterly destroyed by this vintage piece of kitchenware.

The Beast - My Giant Pressure Cooker Canner
©2011 ColinFraser

Speaking of vintage, this thing is a classic.  It is a huge 20-Quart Presto from the 1970s and doesn't have any of the annoying safety interlocks of its modern counterparts.  The "Harvest Gold" enamel color attests to its age!  I bought it on eBay for $31 (plus some serious shipping - it's heavy), and I think I got a great deal because the "Harvest Gold" color has fallen out of style.  It reminds me of a Gibson Les Paul guitar from the 1950s whose mustardy color came to be known as "TV Yellow."  It was designed to show up well on black-and-white TV, but wasn't so popular after color caught on.

So, what goes in this monster?  Well, I ordered some pre-measured P668 Orchid Seed Germinating Media from the Orchid Seedbank Project.  Aaron sells it in packets that you just add to a liter of water and dissolve - simple.  I have also been collecting jars to put the media in.  My boss has been kind enough to set aside empty "palm hearts" jars for me, and I think those will make excellent replate flasks, but the most popular thing for Amateur Orchid Seed Germination ("mother flasks") is probably the 4oz baby food jar.  I don't, and never have had, kids; how else would I have time for all this Orchid Madness?!  So, I went back to eBay looking for empty jars.

Cleaning Jars in the Sink
©2011 ColinFraser

I ended up ordering some, and with shipping it worked out to a little over $0.50 per jar (the cheapest I could find them).  During the days while I waited for them to arrive in the mail, I actually looked at baby food in stores - the first time since I had to buy pureed fruit for my breeding Day Geckos years ago.  Imagine my surprise when I discovered that Walmart (I know, I know) has cheap baby food for $0.50 per jar; the food inside is worth less than the glass jar is!!  I could buy full jars, not wait for them to be shipped, feed the contents to my Scottish Terrier, and have them ready to go for the same price and less time than ordering them empty online!  What a crazy world . . .

Preparing to Fill the Clean Jars/Flasks
©2011 ColinFraser

I bought and emptied a few more jars, and my eBay purchases eventually arrived.  I removed the labels and any remaining glue, rinsed them well, soaked the jars and lids in hot bleach water in the sink for a while, and then rinsed them again.  Now my jars were ready to become flasks.

I added the media to a liter of distilled water, brought the mixture to a boil on the stove, and stirred while everything dissolved.  I let it cool slightly and then dispensed it into the jars with a "flavor injector" syringe.  There are almost 34 ounces in a liter, so it was no problem filling 30 jars with one ounce each.  I then put the lids on LOOSELY and arranged them all in the pressure cooker.

Following the manufacturers instructions (which I found online), I sealed it up and then vented the chamber for 10 minutes.  Once steam had displaced all of the air inside, I placed the pressure regulator over the vent, and the pressure began to build.

Sterilizing Heat and Pressure
©2011 ColinFraser

 When the gauge reached at least 15 psi and the regulator began to "jiggle,"  I let it run for at least 15 minutes at that level, before turning off the heat and letting it cool slowly.  My media was now autoclave sterilized and my "jars" had been transformed into "flasks."

The Agar in the Media Turns to Gel
©2011 ColinFraser

As the flasks cooled the media solidified, and I tightened the lids as I removed them from the pressure cooker.  I also intentionally opened one flask and exposed the media to the air for a few moments.  This will serve as my "contamination control" flask; it is virtually guaranteed to be contaminated.  When growth of contaminants is detectable in this flask, I can check it against the other ones, which will still hopefully be pristine.  At that point, I know that the remaining flasks are safe to use for Orchid Seed Sowing.  Neat huh?

Clean and Sealed
©2011 ColinFraser

Finally, I placed the cooled and sealed flasks into my still unfinished glove-box and misted bleach solution on and around them.  I let them sit for a bit; then I donned a pair of gloves, wiped each one, and wrapped some cling film around the lids.  Hopefully, this will prevent the entrance of contaminants if the flasks "breathe" a bit with changes in temperature and pressure.

Now all that's left to do is wait a couple of weeks and see how much, if any, contamination develops.  I have a couple of seed pods that are nearing readiness, so these flasks should be ready just in time!