Unicorn bags are made from polypropylene which has a melting point of 160c and thus autoclave/pressure cooker safe.
To use, fill the gusseted bags about half way then fold, like wrapping a Christmas present, by tucking in the sides and then tucking the open top under the bag before sterilization. Bags compress after sterilization as a vacuum is formed inside your autoclave/PC.
When cooling, the bags take air back in through both the filter and the unsealed top of the bag, so cooling should be done in your most sterile location.
Inoculate through the top of the bags (working in a sterile environment so as to avoid random fungal spores getting in from the air), and then seal the bag end – best with an impulse sealer.
- Type 4 = 46cm x 10cm – Best for grain spawn (1 of these for X Type 3 Fruiting bags when used at 20% w/w).
- Type 10 = 46cm x 13.5cm – Best for grain spawn or fruiting – Holds about 2.5L/2kg of rehydrated wheat seeds.
- Type 3/14 = 48cm x 20cm – Best for fruiting
- Type XLS = 61cm x 25cm x 13cm – Best for fruting but you need a large autoclave.
As a rule, bacteria start at about 1um and above. Fugal spores start at around 2um. So filter type A and T should stop all contamination entering the bags. Type B will potentially allow both forms of contamination into your bags. However, many commercial farms use B successfully and it is often recommended as the best for fruiting bags due to increased gas exchange aiding substrate colonisation.
- ‘A’ – 0.5um pore size –Best for Shiitake but good for most fruiting bags.
This is from Unicorn: “Our Type A filter is designed for shiitake cultivation. It has a nominal 0.5 micron pore size meaning 80% at 0.5 micron and some over and some under. It is also made to have only 50% approximately area for breathing. This allows shiitake mycelium to grow in higher CO2 environment.
- ‘B’ – 5um pore size -Best for fruiting bags if your grow rooms are very clean.
This is from Unicorn: “Our Type B filter has a high gas exchange ?characteristics, with over 90% area has pores and pore size is higher than the A filter which is 5 microns. Due to this characteristic B filtered bags can be sealed before autoclaving. Most other bags either the filters ?allow competing fungi to go through or too small pores that will pop during autoclaving.”
- ‘T’ – 0.22um pore size -Best for spawn production, too restrictive for fruiting.
This is from Unicorn: “Our T filter has 0.2 micron pores and 90% efficient and is designed for spawn producing.”