How to Use a Spore Print | Agar, Liquid Culture & Grain Guide

The complete guide to turning a single spore print into fully colonised grain spawn -- with a shopping list of everything you need.

Why start with a spore print?

A spore print is a collection of millions of microscopic spores deposited onto aluminium foil or between two glass plates, from a mature mushroom cap. It contains all the genetic material needed to grow new mushrooms.

Compared to spore syringes or spore vials, a spore print gives you maximum versatility:

Our Psilocybe cubensis spore prints
are laboratory-quality, prepared from fresh specimens, and available in 15+ strains including Golden Teacher, B+, McKennaii, Mazatapec, and many more.

The 4-stage roadmap

Think of the process as four stages, each building on the previous one:

Let us walk through each stage and everything you need along the way.

Stage 1: From Spore Print to Agar Plate

This is where it all begins. You transfer a tiny amount of spores onto a nutrient-rich agar plate, where they germinate and grow into visible mycelium within 5 to 7 days.

Supplies needed for Stage 1

Preparing your agar plates

A simple and proven recipe for malt extract agar (MEA):

Mix the ingredients in an Erlenmeyer flask. Sterilise at 15 PSI for 20 to 30 minutes in your pressure cooker, then pour into your sterile petri dishes inside a clean workspace. Let them cool and solidify completely before use.

Transferring spores to agar

Wipe down the inside of your SAB and the outside of your spore print packaging with an alcohol prep. Put on sterile gloves and a face mask.

Flame-sterilise your scalpel or inoculation loop until glowing red, then cool it by briefly touching it to the agar surface at the very edge of the plate.

Gently scrape a tiny amount of spores from the foil. You need far less than you think. A barely visible dusting is more than enough for one plate.

Streak the spores across the agar surface in a zig-zag pattern. This spreads individual spores across the plate for better germination.

Wrap the plate with Parafilm to seal it. Label with the strain name and today's date using a marker.

Store the plate at 23 to 27 degrees Celsius in a dark place. Within 3 to 7 days, you should see white, thread-like mycelium spreading across the agar. This is your culture coming to life.

Stage 2: Agar-to-Agar Transfers (Cleaning Your Culture)

A spore print contains millions of spores with diverse genetics, and it may carry trace contaminants from the environment. This is why experienced cultivators perform 2 to 3 agar-to-agar transfers before moving forward.

Each transfer leaves contamination behind and narrows down the genetics toward stronger, faster-colonising mycelium. Think of it as selecting the best performers from a crowd.

How to transfer

Look for the healthiest, most vigorous area of mycelium on your plate. Strong, white, rhizomorphic (rope-like) strands are ideal. Avoid any areas near discolouration or contamination.

Flame-sterilise your scalpel, let it cool, then cut a small wedge of agar (roughly 1 cm squared) from the leading edge of the healthy mycelium.

Place the wedge mycelium-side down onto the centre of a fresh agar plate. Seal with Parafilm, label, and incubate.

Repeat 1 to 2 more times until your plate shows only clean, uniform mycelial growth with no signs of contamination.

Stage 3: From Agar to Liquid Culture

Once you have a clean agar culture, you can expand it exponentially by transferring a piece of colonised agar into liquid culture (LC). Liquid culture is a nutrient-rich broth where mycelium grows in suspension. It can then be drawn up into syringes to inoculate multiple grain bags, making it incredibly efficient for scaling your grows.

Option A: Use ready-made liquid culture vials (recommended)

Pre-made, sterile Liquid Culture Growth Medium
vials contain a sterilised nutrient solution. Simply transfer a small piece of your clean agar culture into the vial using a sterile scalpel, and shake daily.

Within about one week, you will have a living mycelium culture ready to inject into grain.

Option B: Make your own liquid culture (DIY)

If you prefer making your own, here is a simple recipe:

Ingredients

Equipment

Process

Mix ingredients, pour into your jars, and sterilise in a pressure cooker at 15 PSI for 30 minutes. Let cool to room temperature.

In your SAB, use a sterile scalpel to transfer a small scraping of surface mycelium from your clean agar plate into the liquid. Avoid dropping in too much agar -- just the mycelium.

Seal and store at room temperature. Swirl or shake the jar daily to break up the mycelium and encourage even growth.

After 1 to 2 weeks, you will see fluffy mycelial growth throughout the liquid. You can now draw up this culture into a sterile syringe and use it to inoculate multiple grain spawn bags.

Stage 4: Inoculating Grain -- The Final Step Before Fruiting

With your liquid culture (or a clean agar plate), you are ready to colonise grain. Colonised grain becomes your spawn -- the engine that drives colonisation of your bulk fruiting substrate.

Option A: Use sterile spawn bags (easiest)

This is the path of least resistance and the one we highly recommend, especially when starting out. Pre-sterilised spawn bags come with a self-healing injection port and 0.2 micron filter patch, so you never even need to open the bag:

Simply inject 2.5 to 5 cc of your liquid culture through the injection port. Incubate at 20 to 24 degrees Celsius. When you see 7 to 10 cm of mycelial growth, gently knead the bag to spread the colonisation. Once fully white, mix with substrate in a monotub.

Option B: DIY grain preparation with rye berries

For the full hands-on experience, you can prepare your own grain spawn using Organic Rye Berries:

Wash the rye berries thoroughly and soak them overnight (12 to 18 hours).

Drain completely, then spread the grains out and let them surface-dry until no visible moisture remains.

Load into jars or Grow Bags with Micronfilter. Sterilise at 15 PSI for 90 minutes.

Once cooled, inoculate with liquid culture via syringe, or drop in agar wedges cut from your clean plate.

Shake the jar or bag when approximately 30% colonised to redistribute the mycelium. Full colonisation takes 2 to 4 weeks.

Your complete shopping list

Here is everything you need in one overview. You likely already have some of these items at home.

You will also need a pressure cooker (15 PSI capable) and 70% isopropyl alcohol, both widely available at kitchen and pharmacy stores. A still air box can be made from any large transparent plastic storage box.

Avoid the number one mistake: do not skip agar

We see it all the time: enthusiastic growers try to go directly from spore print to grain, skipping agar entirely. The result? Contamination. Slow, uneven colonisation. Wasted time and materials.

Agar is your quality control step. It lets you:

Your success story starts here

Picture this: a few weeks from now, you open a grain spawn bag to find it fully colonised -- a dense, white network of healthy mycelium that you grew from a single spore print. You mix it into a monotub and within days, tiny pins start pushing through the surface. A week later, you are harvesting your first flush of beautiful mushrooms.

That is the power of learning to work with spore prints. It is the difference between following instructions on a grow kit and truly understanding the life cycle of the organism you are cultivating.

Happy growing.