I have access to a scale but got sick of borrowing it to measure this.
1 Liter water
300 G potatoes
17-20 G Agar
2 G Brewers Yeast
10 G Dextrose
Here are cooking measures that make the same measurements.
Put 3 cups of water in a 4 cup measuring cup.
Cut up one large red potato(unpeeled)and push the chunks into the water till it reads 4 cups.
pour it in a pot.
Add 1 more cup of water so your 1 cup of potatoes are being boiled in 4 Cups of water.
Boil for an hour and drain.
Keep the water,eat the potatoes.
Add water to bring up the level to 4 and 3/4 Cups.
The following are LEVEL measures...
Drag the back of a knife over a heaped measuring spoon to make it flat.
2 Tablespoons + 1 Teaspoon of Agar
3/4 Teaspoon (1/2+1/4)Brewers Yeast
1 Tablespoon +1 Teaspoon of Dextrose
mix the dry.
Heat the potato water in the microwave or on the stove till hot again.
Mix the dry ingredients together then add the dry to the water while stirring.
Pour it sterilize it and use it.

Interesting post peterthinks.
I wish that I had more to add, but I'm not much of a grower.
I plan on getting into cultivating some edibles one of these days. My only attempt at it failed some years ago and I have not tried since. I think it would be a good thing to do during the winter months when nothing growing out in the fields.

That's exactly what I am doing!
Forrage in the spring summer fall,clone the interesting finds and grow during the winter!
I'm done scouring the woods and fields for this year and the lab is ready to go.I just want to finish my glovebox with a filtered air system.
I just started last year building the lab and getting into cloning and haven't had a sucessfull grow yet either(other than a few sprouts in dishes)
But I've done a lot of agar work and have a bag of oyster I'm trying to get to pin right now.
Keep at it!Don't give up cause one grow didn't go well...try an easy mushroom like oyster or enokie.

Peterthinks

But should one start from scratch and go through the whole sterilization process, starting with raw ingredients and building a sterile room dedicated to cultivation? I picked up a book on cultivation a few years ago but it was not designed for the beginner. The way the book talks about it, makes growing seem impossible.
I've always wanted to grow some oysters, so that would be where I would start if and when i do try again. Doing some more research on it now.

Well you can get by with just pasturization for some things
www.ncbe.reading.ac.uk/NCBE/MATERIALS/MICROBIOLOGY/oyster.html
and you can buy pre sterilized agar filled plates but the cost of buying sterile supplies and just making your own are very different!
it's fall and you can get a good deal on a pressure cooker now.
www.kmart.com/catalog/search.jsp?N=0&...tt=pressure%20cooker
You don't need a room dedicated to it.
If you're carefull you can get by with a clean stretch of counter.
I have the room so I took over a spare room but I started on the kitchen counter.

Wow! Oysters on a toilet roll L OL! I got to try that. Looks so easy.. Ever tried it yourself? I'll justr have to get some oyster cultures.. Would be nice to create one from the actual tissue of the fruit bodies. Those pressure cooker deals look nice too.
Thanks for the links and info.