[Tastebridge] Mushroom update

Roger H domitron at yahoo.com
Wed Oct 5 14:17:22 PDT 2011


I just used my last bit of sawdust, but I will be getting some very soon.  In the meanwhile, of course, I have vermiculite, which is personally what I would recommend if I were trying to maximize the fruiting potential of sawdust and, probably, coffee grounds too.  While vermiculite doesn't provide any food for mushrooms like sawdust would, it is special in that it has the highest water retention capability of any commonly used amendment (saturation is at a whooping 84%!).  It holds all of that water without affecting the chemistry of the substrate and improving the looseness of the substrate (i.e. reducing density).  Even better, it holds the water tightly until it is needed, not drying out easily like uncolonized sawdust for example.  It basically acts like a sponge or water reservoir, which is a good thing since most of the time the limiting factor in keeping older blocks flushing is water (i.e. they just dry out and cannot be
 easily rehydrated because of the tight mycelium binding). 
 
One thing about using vermiculite, though, is that the feel test becomes even more critical.  Why?  Because depending on how much is used, vermiculite can actually drive the appropriate water capacity for the substrate to a bit higher than without it.  For example normally a supplemented, sawdust-based substrate is prepared around 60 to 65% moisture content, but if a lot of vermiculite is in the mix, it might be better to shoot for 66% and maybe one could even get away with 68%!  And an experienced grower can feel it if that is the case.  The more you work with substrates, the more you know what to look for and how it should feel.  And vermiculite can easily change the overall feel by soaking up a lot more water (per dry weight) than other components of the substrate.
 
Roger
  

 

________________________________
From: Rikke Rasmussen <rikke.c.rasmussen at gmail.com>
To: Roger H <domitron at yahoo.com>
Cc: Tastebridge <tastebridge at lists.noisebridge.net>; Dan Willhite <willhite at gmail.com>; "bio at lists.noisebridge.net" <bio at lists.noisebridge.net>; Natalie C Underwood <underwnc at clarkson.edu>; "noisebridge-discuss at lists.noisebridge.net" <noisebridge-discuss at lists.noisebridge.net>
Sent: Wednesday, October 5, 2011 11:21 AM
Subject: Re: [Tastebridge] Mushroom update


Agreed. We'll be good little citizen scientists and do it right, measurements and all. 
We're out of sawdust; does anyone have some vermiculite we could use? And Roger, if you're coming, can we borrow your scales?  
/Rikke  
On Oct 5, 2011 10:33 AM, "Roger H" <domitron at yahoo.com> wrote:
> Yes, I should be available next Monday. 
> 
> The experiment sounds good, except I do not think gypsum has sufficient water retention to serve to dry up the substrate.  Typically gypsum serves to improve the texture of a substrate or, in spawn generation, to reduce water between grains so they don't grow as a hard pack which cannot easily be broken for mixing or dispersal.  It has a secondary function in some cases as a calcium supplement and long-term pH reducer, good for some wood-loving species. 
> 
> Vermiculite is a good sponge to dry up substrates but it is not the most environmentally sustainable choice.  Another addition that can dry up the grounds would be a small amount of hardwood sawdust.  Sawdust is largely  a waste byproduct of other industries so might be a better choice than vermiculite.  Furthermore, sawdust provides more food for the mushrooms and is less expensive than vermiculite per pound (some sources can be practically free). 
> 
> Regardless how one does it, the final substrate should pass both the feel test and the microwave dehydration test.  Without them you are shooting in the dark in my opinion.
> 
> Sent from my iPhone
> 
> On Oct 5, 2011, at 9:52 AM, Rikke Rasmussen <rikke.c.rasmussen at gmail.com> wrote:
> 
>> We decided to try three different experiments with regards to the moisture level - one where we dry the grounds out first and treat it the same way we did the sawdust (i.e. add peroxide and supplement); one where we adjust moisture level of wet grounds (perhaps with gypsum?) and add peroxide + supplement; and one where we adjust the moisture level of wet grounds and pressure cook them before inoculation.
>> 
>> Mike, can you get me about 3-4 times as many grounds for next week as you got me last time? And Roger, are you available on Monday?
>> 
>> Jake, if you're listening in on this thread, I'll bring parts for automation of the humidifier On Monday - will you be there?
>> 
>> What have I left out?
>> 
>> /Rikke
>> 
>> On Oct 4, 2011 4:28 PM, "Roger H" <domitron at yahoo.com> wrote:
>> > Growing on coffee grounds will probably require some moisture balancing unless by some miracle the coffee grounds just happen to be between 60 to 65% moisture content (per weight).  One method could be actual drying/moistening of the grounds or mixing drier and wetter grounds together to achieve the required moisture content.  Alternatively if the moisture is slightly high, a modest amount of vermiculite could be added to soak up the excess moisture.  pH should also be considered.
>> > 
>> > Coffee grounds have a fairly high buffering capacity and happen to have an ideal pH for oyster growing, so we probably won't need additional calcium carbonate, although gypsum might still be useful to provide calcium without a significant pH impact.  And then there is the question of supplementation. 
>> > 
>> > Substrate supplementation is a yield optimization, never a strict requirement per se.  Substantial yield increases are not uncommon, although I simply don't know if supplementation would serve oyster my going through coffee grounds as well as it does hardwood sawdust/chips.  I would recommend a scientific approach applied, recording yield with varying amounts of Spawn Mate SE supplementation like we did before.  Given the impetus of growing on coffee grounds is largely to improve the sustainability of the operation while simultaneously reducing expense, it would be consistent with these higher ideals to minimize supplementation, even if higher levels result in modest yield increases.  The level that gives us the biggest bang for our buck, so to speak, can only be evaluated once adequate data is available on the efficacy with this particular substrate and grow environment against the level of supplementation.  Likewise, less
>> > expensive and less environmentally impacting bags, such as the compostable garbage bags I introduced, should be tried along beside the regular spawn bags because compostable food-grade garbage bags are nearly an order of magnitude less expensive and impact the environment less since they require less energy to manufacturer (in addition to composting rapidly).
>> > 
>> > Roger
>> > 
>> > 
>> > 
>> > ________________________________
>> > From: Dan Willhite <willhite at gmail.com>
>> > To: Tastebridge <tastebridge at lists.noisebridge.net>
>> > Sent: Tuesday, October 4, 2011 3:25 PM
>> > Subject: [Tastebridge] Mushroom update
>> > 
>> > 
>> > 
>> > 
>> > For everyone at the mushroom meeting last night, I checked at my local Peet's coffee and they are very willing to give away used coffee grounds. The woman I talked to seemed to say they had as much as I wanted whenever I wanted. On the next sunny day, I'll swing by and try to get a couple of large trash bags full and dry them on my roof. Hopefully, we'll get a warm day before next Monday. 
>> > 
>> > Cheers --Danny 
>> > _______________________________________________
>> > Tastebridge mailing list
>> > Tastebridge at lists.noisebridge.net
>> > https://www.noisebridge.net/mailman/listinfo/tastebridge
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