Growing Nameko on Supplemented Hardwood sawdust.
I've been cooking substrate today. I have a couple of jars of Nameko grain spawn over due spawning to substrate. They were inoculated 15th March with liquid culture bought from a UK supplier. If anyone wants to know where exactly I can post over in the dedicated supplier discussion thread. The grain is 'pop corn' as usual (for me). They were ready a month ago really. I've not had the spare energy to spend on hobbies in recent weeks. I think they have produced some myco-piss as there is yellow staining; can anyone give an experienced opinion on the photo as I am not 100% sure it is not contamination of some sort? I'll use it anyway and see what happens. If it turns nasty in the substrate it can go outside.
Supplemented Sawdust Formula based on Stamets'
The substrate is hardwood sawdust supplemented with 20% wheat bran by dry weight and a final moisture content of around 60%. Stamets' recipe includes gypsum (calcium sulphate) but I don't have any and I do not believe it is necessary for my 'hobbyist' level of production - if I were attempting a commercial grow I'd be inclined to source all suggested ingredients and follow the procedures from Stamets' GGaMM to the letter. I have used this recipe excluding Gypsum previously, to grow Lion's Mane with reasonable success i.e. healthy long lived blocks.
The most economical source of hard wood chips/dust that I could find in the UK (taking into account I want a few kilos not a few tonnes) was "Briquette Heat Logs", probably known as something else in other regions of the world. Essentially they are quite course hardwood saw dust formed into approx. 3 1/2" diameter logs by heat and pressure - no glue added to hold it together. the courseness is good as if your saw dust is too fine it reduces aeration in the mixture. They are approx. £1 per kg here which is fine for my purposes. Each 'log' in the box I got is about 1.8kg and they are not too easy to break up so I just do a batch of substrate from one 'log'. They disintegrate quite quickly once you pour hot water on them but I don't want to store wet/damp HW saw dust. I could also saw them up to get specific weights but just can't be bothered - seems to much risk on the table saw and hand sawing hurts my sore joints.
Finding the weight of bran to add.
The Hardwood 'Log' Briquette was 1.85kg, this will represent 80% of the total dry weight, so divide by 80 then multiply by 20 gives the weight of bran needed.
(1.85/80) x 20 = 0.46kg of Wheat Bran
Back check calculation:
1.85kg Hardwood 'Log' Briquette - (compressed HW sawdust) + 0.46kg Wheat Bran ------ = 2.31kg total dry weight ------ (0.46/2.31) x 100% = 20% of total dry weight (near as damn it anyway, I'm not weighing out to the nearest gram).
Calculating water for 60% - 65% moisture content.
The total wet substrate will have 40% weight from dry ingredient and 60% from water.
(2.31 / 40) x 100 = Total wet weight = 5.775 kg Total Wet weight - Dry Ingredient Weight = Weight of water to add 5.775 -2.310 ----- =3.465 ----- Round to 3.5L water (NB: 1L water weighs 1kg)
Back check calculation:
2.31kg <-- Total of dry ingredients + 3.50kg <-- Rounded up amount of water ------ = 5.81kg Total wet weight (Nearly 13lbs for those who prefer non metric) ------ (3.5/5.81)*100 = 60.24% moisture by weight. Rounding up the water volume made little difference and it is still in the 60% <-> 65% range.
This makes enough substrate for 3 of the filter patch bags I happen to have, leaving enough room for the spawn to be added and mixed in later after sterilisation. The bags are 25cm x 50cm x 6cm and the filter patch is about 3/4 the way up the bag. I find it rather easy to over fill them, about 4lbs is enough per each of these bags. Also this fill level helps them fit safely in my 21L pressure cooker.
I put the log in a large plastic bucket that can stand boiling water, boil the 3.5L of water and pour it in. The log quickly absorbs the water and expands and starts breaking up. You could probably just leave it to it but I like to get hands on and help it along by breaking it up and mixing to get the water evenly distributed/absorbed by the wood. It was late evening so I left it over night to fully absorb the water then this morning added the Wheat bran and mixed thoroughly. I shared the substrate out between 3 filter patch bags. Only 2 fit in my PC at a time so it'll be 2 runs, annoyingly the second run is with a half load which seems inefficient but never mind. If I was more active in the hobby I'd probably have other bits and bobs I could add to the PC to make use of the space but I don't right now. Baring in mind my PC only does about 12.5 PSI I will run it for at least 2 hours for the full load and maybe 1.5hrs for the half load. It'll take time for the heat to penetrate to the centre of the full load, 2 bags is a tight fit. The bottom and sides of the bags are protected from direct contact with the PC body by 2 layers of cloth, the bags tops are folded over and will likely pull in tight on cool down but as a precaution for safety during the run I put a small diner plate on top of the bags to ensure they cannot open up and block the pressure vent or safety valves etc. I add about 2L of water to the PC and this comes up nearly 1/2 of height of the PC body due to the volume mainly being filled with substrate bags. Seems high but I do not want to risk running dry.
PC is allowed to cool down naturally - I don't like forcing fast cool down, I am not at all confident my cheap PC would survive repeatedly doing that.
Spawning tomorrow seems likely - I have home repair/DIY to do now and the PC/bags will take many hours to cool down any way.
I will try and keep posting methods and progress here.
Edited by Cuboid, 16 May 2020 - 12:00 PM.