Spore Syringes

How to use spore syringes to inoculate grain jars — sterile technique, storage, and what to expect.

What Is a Spore Syringe?

A spore syringe is a sterile syringe filled with water that contains mushroom spores in suspension. It is the most common and beginner-friendly way to start a mushroom grow. When injected into sterilised grain, the spores germinate and grow into mycelium, which eventually colonises the entire jar.

Spore syringes are typically 10–12 ml in volume and contain millions of spores. One syringe is enough to inoculate 5–6 grain jars, which is plenty for a single monotub grow.

Tip: Spore syringes contain a random mix of genetics. For more consistent results and faster colonisation, consider making a liquid culture from your spore syringe first (see the Liquid Culture guide).

Where to Buy Spore Syringes

Purchase spore syringes from reputable vendors who specialise in mycology supplies. Good vendors will:

Ship syringes with clear labelling of the strain and date.
Use sterile packaging and sealed caps.
Have positive reviews and a track record in the mycology community.
Offer a variety of well-known strains (Golden Teacher, B+, etc.).
Provide customer support if you receive a contaminated syringe.

Look for vendors on mycology forums, Reddit communities (such as r/sporetraders), and dedicated mycology supply websites. Avoid buying from random marketplace sellers with no reviews.

Warning: Always check the laws in your jurisdiction before purchasing spore syringes. In most places, spore syringes are sold for microscopy and research purposes only. Ensure you comply with all local regulations.

Storage

Proper storage keeps your spore syringes viable for months:

Storage Method	Temperature	Shelf Life
Refrigerator (recommended)	2–8°C (36–46°F)	Up to 12 months
Room temperature	20–25°C (68–77°F)	1–2 months
Freezer	Below 0°C	Not recommended — ice crystals damage spores

Store syringes in the fridge in a sealed zip-lock bag.
Keep them away from light.
Always keep the cap on the needle to maintain sterility.
Let the syringe warm to room temperature for 30 minutes before use.

Sterile Technique Basics

Contamination is the number one cause of failed grows. Spores and grain are food for mould and bacteria, so you need to work as cleanly as possible. You do not need a professional lab — a simple Still Air Box (SAB) is sufficient for spore syringe work.

Still Air Box (SAB)

A SAB is a large clear plastic tub with two arm holes cut in one side. It creates a zone of still air that dramatically reduces the chance of airborne contaminants landing on your work.

Take a large clear storage tub (60–80 qt / 55–75 L).
Cut two arm-sized holes in one of the long sides, about shoulder-width apart. Smooth the edges with tape.
Before each use, wipe the inside with isopropyl alcohol (70%) and let it settle for 5 minutes.
Work slowly and deliberately inside the SAB. Fast movements create air currents that carry contaminants.

Essential Supplies

Isopropyl alcohol (70%) — for wiping surfaces, gloves, and injection ports. 70% is more effective than higher concentrations because the water helps it penetrate cell walls.
Nitrile gloves — wear them and spray with alcohol before starting.
Lighter or alcohol lamp — for flame-sterilising the syringe needle.
Paper towels — soaked in alcohol for wiping.

Danger: Never use isopropyl alcohol near an open flame. Spray alcohol onto a paper towel away from any flame source, then use the towel to wipe surfaces. Alcohol vapour is highly flammable.

How to Inoculate Grain Jars

Once your grain jars are sterilised and cooled (see the Grain Spawn guide), you can inoculate them with your spore syringe.

Step-by-Step Inoculation

Set up your SAB. Wipe the inside with 70% isopropyl alcohol. Place your grain jars, spore syringe, lighter, and alcohol wipes inside. Let the air settle for 5 minutes.
Put on gloves and sanitise. Spray your gloved hands thoroughly with alcohol.
Shake the syringe. Spores settle to the bottom over time. Shake the syringe vigorously for 10–15 seconds to distribute the spores evenly throughout the water.
Remove the cap and flame the needle. Take the cap off the syringe needle. Hold the needle in the flame of your lighter until it glows red-orange. Let it cool for a few seconds — do not blow on it or touch it.
Wipe the injection port. If your jar lid has a self-healing injection port, wipe it with an alcohol-soaked paper towel.
Inject the spores. Push the needle through the injection port and inject approximately 0.5 ml of spore solution. Pull out and move to a different spot on the grain surface (rotate the jar). Inject at 4 different points around the jar, for a total of about 1–2 ml per jar.
Flame between jars. Flame-sterilise the needle again before moving to the next jar. This prevents cross-contamination if one syringe or jar has an issue.
Seal and label. Once inoculated, set jars upright and label them with the strain name and date.

Tip: Injecting at 4 separate points around the jar gives the mycelium 4 starting locations, which speeds up colonisation significantly compared to injecting all the solution in one spot.

How Much to Inject

Jar Size	Spore Solution	Injection Points
Half-pint (250 ml)	0.75–1 ml	2–3 points
Pint (500 ml)	1–1.5 ml	3–4 points
Quart (1 L)	1.5–2 ml	4 points

Warning: Do not over-inoculate. Injecting too much liquid adds excess moisture to the grain, which creates conditions that favour bacterial contamination. More is not better — 1–2 ml per quart jar is plenty.

What to Expect After Inoculation

After inoculating your jars, store them in a warm, dark place at 24–27°C (75–80°F). Here is a typical timeline:

Timeframe	What You Should See
Days 1–3	Nothing visible. Spores are germinating. Be patient.
Days 3–5	First signs of white, fluffy mycelium at the injection points. Small white dots or patches.
Days 5–10	Mycelium patches grow outward from injection points. You should see clear white growth.
Days 10–14	Multiple patches visible, starting to spread across the grain surface.
Days 14–21	30–50% colonisation. This is when you do your first break-and-shake (see Grain Spawn guide).
Days 21–35	Full colonisation. Jar should be entirely white with mycelium.

Warning: If you see any green, black, orange, or pink colours in your jar, that is contamination. Do not open contaminated jars indoors. Seal them in a bag and dispose of them outside. See the Troubleshooting guide for more details.

Tip: Spore syringes are slower to colonise than liquid culture because the spores need to germinate first. If you want faster colonisation in future grows, use your spore syringe to make a liquid culture (see the Liquid Culture guide) and use that LC to inoculate your grain jars instead.

Common Mistakes to Avoid

Not shaking the syringe. Spores settle at the bottom. If you do not shake, you may inject plain water into some jars and a clump of spores into others.
Skipping flame sterilisation. Always flame the needle between jars. Always.
Injecting into hot jars. Make sure your grain jars have cooled completely to room temperature after pressure cooking before inoculating. Injecting into warm jars will kill the spores.
Checking jars too often. Moving and tilting jars disturbs early mycelium growth. Check once a day by looking, not by handling.
Giving up too early. Spore syringes can take up to 7 days to show any visible growth. Do not assume failure until at least 14 days have passed with no signs of life.