Boiling mushrooms in water would tend to gas off essential oils, so I would tincture first and decoct later, especially if starting with dehydrated mushrooms.
According to Wikipedia, "to qualify as an alcoholic tincture, the extract should have an ethanol percentage of at least 25–60%. [...] In herbal medicine, alcoholic tinctures are made with various ethanol concentrations, 25% being the most common."
Doing one extraction in alcohol and a separate extraction in water will remove more compounds than doing a mixed extraction of water/alcohol. On a purely pragmatic level 80 proof alcohol is inexpensive and easy to come by in the form of Vodka. Might as well use that for tincture extraction. It's 40% alcohol, so if you extract dry mushrooms, and dilute the tincture 1:0.6 with decoction water you end up with a 25% tincture.
Would you want to adjust the pH of the decoction water to extract a favored class of compounds? For example by using vinegar instead of water.
What do you want to extract into a tincture or decoction that isn't available by eating the mushroom? Are there insoluble parts of the mushrooms that you wish to avoid? I could understand the usefulness of extracting the soluble components out of a woody mushroom like turkey tails.
Well as we say in both permaculture and herbal medicine, it depends. Water and alcohol extract different constituents of herbs, so higher/lower proof depends on what you are wanting to extract and that usually comes from what the point of the final medicine is. For every herbalist who says reishi is best at x concentration, another will say they've had great results with y. There is also an issue about heat (heating can release/activate some parts of plants/fungi that wouldn't be otherwise). In general heat/long decoction will extract more immune properties, alcohol will get the adaptogenic properties.
If you are doing a double extraction, then the final alcohol% is going to be different i.e. you can make a 96% tincture, but not using a method that involves decoction as well.
I use reishi as a decoction, and haven't made tincture yet, but here are the recipes I would consult. They come from expert level herbal medicine practitioners (Michael Moore and Robyn Klein. Klein is a hardcore scientist, if that's the important thing).
I'm really excited about my new mushroom hobby but, as a realist I would like to challenge everyone out there, mushrooms will not be able to save the world, much less me, with out a free flow of accurate information that the worker bees can use to proliferate this technology.
Again, as with both permaculture and herbal medicine, these things are both science and art, and both theory and practice. What I have found with both is that I can learn from the experts but I need to get my own experience to be able to make good judgement calls about what is best in any given situation. There are no absolutes, everything depends. This is a good thing btw. I agree with you about a free flow of information
To that end one thing you can do is make smaller amounts of 3 different tincures. One is a alcohol tincture. One is a decoct then tincture tincture. One is a tincture then decoct tinctures. Try them out, see what happens. Strongest isn't always best, and using herbal medicines is an exceptionally good way to learn more deeply.
Rose, I hear what you are saying and that's good advice! I can be a bit to rigid at times but it helps me find the truth. You and Joseph are helping me get the foundation with which I can start out into an art form that will take me far. Thanks for the great recipes. For myself, I'm looking for more immune boosting properties. For my sister I'm looking for adaptagenic properties. Thanks again for the great info.
To the rest of you out there, don't stop now, I haven't seen good info like this anywhere.