Unicorn Filter Patch Bags SM-4T


4T Unicorn Brand autoclavable bags are popular for making small quantities of mushroom grain spawn.  Fill with substrate and sterilize.  Once cool, inoculate with your mushroom culture and seal.  The filter allows for air exchange, while keeping contaminants out.   Small size bags (4″ X 3″ X 18″) with 0.2 micron filter.

**Lowest Price to your door.  As low as $745.85/box with bulk discount and payment via etransfer**

Save When You Mix & Match

2.5% with 2-4 boxes

5% with 5+ boxes

Unicorn Filter Patch Bags SM-4T $15.99$801.99

Free Canadian shipping on orders over $150

  • Most orders ship in 1-2 business days
  • We guarantee the quality of our products
Unicorn Filter Patch Bags SM-4T

Unicorn 4T bags are made for mushroom growing, and are a popular choice for those wanting to make small quantities of grain spawn.

Fill with your desired substrate such as cooked rye, fold the top of the bag down, and sterilize in an autoclave or pressure canner at 15psi.  Made of polypropylene, these mushroom growing bags can withstand this extreme heat.  However, be sure to follow the equipment manufacturer directions.  A couple of our customers have melted their bags by not using the necessary amount of water in a pressure cooker.

After sterilizing substrate, let cool then inoculate with a mushroom culture in your sterile lab or “still air box” and seal.  Bags can be sealed with an impulse heat sealer, bag clamps, or zap strap.  The finer “T” filter provides for air exchange while keeping out mold spores and contaminants larger than 0.2 micron.

*Product low in stock, delays may occur

4T – (0.2 micron) (4″ X 3″ X 18″) 3.0 Mil Polypropylene
Size Small: Holds ~2.5lbs substrate

LOWEST BOX PRICES delivered to your door.  We ship in 1-2 business days from within Canada.  No hassle clearing customs, nor unexpected cost of brokerage and duty.  If you find a lower price including shipping and brokerage, give us a chance to beat it!

FOR FULL BOXES SAVE AN EXTRA 2% when paying by etransfer!
Select to pay by etransfer at checkout, and fill in customer note with request for etransfer discount.  We will apply the discount and email you a revised invoice.

Additional information


10, 100, 1000