Liquid Culture

Liquid culture would be consider, to my point of view; the first stage of growth of mycelium.
Is ideal to keep colonies thriving for long periods of time and start a new community.
There are a lot of recipes out there to keep them going on a liquid media. My personal favorite is always the easiest one, so: Water and Honey.
For 400 ml of water I'd dissolve about 15 gr of honey.
My favorite part of this type of colony conservation is that it can be sterile in any media with a fixed cap like Alex Dorr recommends. He's got a book called Mycoremediation handbook and some videos on how to grow mushrooms that are very handy for a beginner like I once was.
So, basically the way to go with liquid culture jars is to have a sterile breathable port and a self-sealing port for syringe transfusions. I'm not sure if you could buy them done already but making your own is very easy. All of the materials are available on amazon or ebay or any of those handy e-shops.
This is how mine ended up looking like. I decided to start working with 8oz regular lid mason jars, just because they're pretty manageable and eventually they'd be cool to transport (also the proportion is very cute) and if you're only doing some experiments without having the precise formulas already, is a good way to go without wasting too much material.

The sterile breathable port is a syringe filter (in this case 22 microns). This allows O2 to go in, which is mandatory cause mushies need O2 to breath.
The gray thing is a silicone self-healing port. This is used to take liquid from the jar (use a new syringe to avoid contaminating the whole jar) and also to immaculate the solution.
After preparing the honey and water solution, autoclave the liquid to ensure a sterile environment inside the jar. Then, immaculate it with a liquid culture of some mycelium, or agar grown mycelium.