Wow that's not bad, what temp do you store them in, is any heating necessary?
I recently started breeding fruit flies for our 3 poison dart frogs. It is really easy, and you learn real quick not to pour boiling hot water into a plastic jar...like I did...and will never do again...lots of melted plastic jars and wasted time. Luckily, I hadn't added the Repashy Superfly mix yet, so I didn't waste any of that.
I have had great luck using Gatorade bottles for my cultures with a coffee filter rubber banded over the top as a lid, so far, no escapees until we go to feed the frogs.
I plan on getting a booth at our next reptile show and selling some of the cultures, since we are becoming overrun with empty Gatorade bottles...I gave up all carbonated drinks about 6 months ago, so I traded one addiction for another, soda/energy drinks for Gatorade, but at least I am able to use the mountain of empty bottles for something.