Jars for substrate
STEP 4. Day 2. How to prepare spawn jars
On the previous step you've already cooked the substrate for magic mushrooms. Now you should prepare jars for it in order to proceed with sterilization.
For this purpose growers use different kind of jars, containers or spawn bags for substrate with inoculation port and breathable air filter.
What is inoculation port and air filter?
Each container, either a polypropylene heat-resistant bag or jar with lid, must be equipped with an inoculation port and a breathing air filter.
Inoculation port (aka injection port) — is an entry point for a syringe needle containing the liquid spore solution or liquid culture to inoculate the sterile substrate. It must be protected agains any competing microorganisms penetration through it. Bactericidal breathable patch, butyl rubber self-healing injection ports (aka bottle stoppers) or heat-resistant rtv silicone sealant is used for this purpose.
Breathable air filter — is an orifice that provides minimal air exchange during the colonization period of the substrate. It must be protected by bactericidal layer to prevent any competing microorganisms from entering through it. Bactericidal breathing patch, Luer lock syringe filters, and synthetic filter disks are used for this purpose.
Mushroom cultivators practice in different ways. Someone makes two holes in the lid: one for injection port and one for filter. Someone makes several ports for inoculation and several filters for air exchange.
In our growing, inoculation port and air filter is one hole. Less holes - less opportunities for contaminants. At the same time, everything is durable, reliable, simple and cheap. Next, I'll show you how to implement it.
Jars for substrate with lids. What are options?
There is a huge variety of materials that can make life easier for growers. Let's take a look at the different options and alternatives.
❇️ Ready-made jars and/or lids with a built-in injection port and filter. Mason jars are often used for such purposes. Lids for Mason jars consist of two parts: a replaceable disposable lid disc with a rubber seal around the rim and a reusable threaded ring. Each lid is equipped with an inoculation port (butyl rubber injection port) and a breathing filter (patch or micropore nylon laboratory filter).
❇️ Lid components. Butyl rubber self-healing bottle stoppers are a great option for an inoculation port. Can also be used in conjunction with high temperature, heat resistant silicone to fully secure the port. They can be installed in any kind of lids, substrate containers or spawn bags.
Luer lock syringe filters are a great option for an air filter. They can be installed in any kind of lids or substrate containers. The syringe filters can be substituted with a bactericidal patch.
❇️ Glass screw jars with heat-resistant plastic lids. You can prepare your own or buy ready-made. Inoculation port - butyl rubber injection port. Filter — laboratory funnel filter or substitute with a patch.
❇️ Ready-made heat-resistant polypropylene spawn bags with inoculation port and air filter.
❇️ Make your own jars and lids for the substrate, as we do.
What to use is up to you!
Jars is more predictable in comparison with spawn bags. It is harder to accidentally injure growing mycelium in jars. In addition, it's easier to detect contamination and souring. That's why our guide is about jars. Let's figure out how to prepare jars for substrate quick, easy and cheap on your own.
How to prepare jars for substrate?
To make DIY jars and lids for substrate you need:
- Jars with lids (volume, types of jars and lids we'll discuss below).
- Screwdriver/nail/awl/drill with a diameter of 5-10 mm.
- Bactericidal breathing patch — 1-2 per lid.
- Heat-resistant rtv silicone sealant — optional.
What volume for spawn jars is needed
Any jar that fits your pressure cooker (autoclave or multicooker) from 250 ml to 1 liter. We use 500 ml and 700 ml jars. For us these are the optimal volumes. The shape of the jars does not matter.
Note: The shape of the jars is important for PF-tek growing. Then the jars need to be cylindrical without a narrowed neck. Or conical shaped (the neck is wider than the bottom), so that you can take out the mushroom cake safe and sound.
Jars more than 1 liter are not recommended. Why?
- First, the jar may not fit in the pressure cooker (multicooker).
- Secondly, a large volume will require more time to colonize the substrate. Accordingly, more risk for souring and contamination, which can take over the substrate faster than the mycelium of psilocybin mushrooms.
- Third, it is better to share the risks and make more jars of smaller volume. So that, increase the chances of future mushroom survival.
- With more jars you can experiment and try different methods. Mycelium in each jar will be genetically unique and there is an opportunity to select the best one.
What kind of jars is needed
We use heat-resistant polypropylene jars with polypropylene lids (withstand temperature up to +140°C or 284°F) and glass screw jars with metal twist-off lids (withstand temperature over +160°C or 320°F) or Mason jars.
Pros of glass jars:
- Easily withstand higher temperatures than polypropylene jars. This point is especially important if your pressure cooker doesn't allow you to set a specific temperature.
- The jar can crack or break during the sterilization process. You can't use such jar and substrate in it for inoculation.
- It is more difficult to shake the substrate that has covered by mycelium.
Pros of polypropylene jars:
- Flexible and elastic (it will be easier to shake the substrate with mycelium in such jars)
- Don't crack or break during sterilization, as it can happen with glass ones.
- Under the influence of temperature changes, the lid can open, then we can't use such substrate for inoculation. Make sure that the lid is tightly closed before and after sterilization.
In fact, we had no problem either with polypropylene (500 ml) or glass (700 ml) jars. The choice is up to you.
Step-by-step spawn jars and lids preparation
1️⃣ Wash all jars and lids. You can use a dish detergent.
2️⃣ Make only one hole in each lid for the injection port and air filter. Diameter about 5-10 mm. Polypropylene lids can be burned through with a red-hot nail/awl or a screwdriver.
For metal lids you can use a drill or punched with a nail/awl or screwdriver.
3️⃣ Tape inoculation port with a breathing bactericidal patch outside. Try to stick the patch so that the breathing dots on the patch show you where the center of the inoculation port is. This will make inoculation more convenient.
🔴 Important: When you make a hole in the metal lid, it is necessary to bend the metal pieces on the back side and seal this place with a breathing bactericidal patch both - inside and outside!
It is necessary, because water drops with rust from the lid accumulated there and contamination can easy get in. For polypropylene jars only one breathing bactericidal patch (outside) is needed.
4️⃣ Inoculation port can be made with heat-resistant rtv silicone sealant. This is a great alternative to butyl rubber bottle stoppers.
Fill the hole for the inoculation port with heat-resistant silicone sealant (rtv silicone) on both sides.
The silicone that hasn't yet solidified should be pressed lightly with a napkin inside and outside of the lid. So that it takes the shape of a tablet or wax seal. Wait for the sealant to completely solidify.
Don't forget to make another separate hole in such lids for air filter and cover it with a bactericidal patch.
Now jars for substrate are ready! You can proceed and move on — STEP 5. Day 2. Substrate sterilization ▶️
Feel free to ask any questions and leave your comments ⬇️⬇️⬇️