cardboard as alternative to straw?

Hey Julian,

welcome to the forum! Yes, when we began growing on coffee back in 2011 we used to use shredded card mixed in and had pretty good success like this for a couple of years. It breaks up the mix reasonably well and if your coffee is very wet it can be added dry and will help to soak up the extra moisture.

Most of the the time though it is best to soak the card in water for an hour or so first (freshly boiled water is ideal to pasteurise it). Then, when it has cooled, squeeze any excess water out and add to the mix at up to 20% of the coffee volume. If you add it dry, most of the time you will create a very dry mix that the mycelium will struggle with.

The main reason we stopped using shredded card was to do with scale and consistency – we wanted a material that was easier to pasteurise/soak in bulk and would mix consistently when on a larger scale. The cardboard tends to clump up in the mix quite a lot so it didn’t work so well in larger batches. Also, whenever we experienced contamination, we suspected the card was the most likely source, so we switched to using straw which gave a much better mix and next to no contamination.

In summary – yes shredded cardboard can work well at a smaller scale and is obviously really easy and cheap to source. Give it a go, and try to pasteurise and squeeze out excess moisture before using.

best wishes, Adam

• This reply was modified 9 years, 3 months ago by Adam.