I myself would use the sulfur to lower the pH of the soil. I've read about people using vinegar to try and modify a soils ph, and they were using standard 5% acidity vinegar, but I've never tried it and I am not sure what sort of affect acetic acid will have on soil biota and other minerals. I have used sulfur to lower the pH for my blueberry bushes, and sulfur takes time, at least one growing season to have a measurable affect. Using sulfur relies on microbes in the soil to do a little chemistry to lower the soils pH, and that only really happens when the soil is warm. Sulfur added to soil in late fall or during winter will have little or no affect on lowering pH until the following summer comes around. Sometimes not all the sulfur added will be converted to sulfuric acid by the soil microbes in the first warm season, and some sulfur can still remain and another round of pH lowering can happen in the second year even though no more sulfur was added.
I hope Redhawk chimes in and maybe he has some knowledge on using vinegar to adjust a soils pH. I really don't know much about it.
I personally would not use Miracid. It's just chemical salt fertilizer and will do nothing to benefit the soil and soil biota and will actually harm the soil food web.
I took a few minutes and did a quick google search looking for studies done by universities on using vinegar to lower a soils pH and really didn't find anything helpful. I did find some garden and horticulture sites that speak of using it, but for me, I am more inclined to trust the reliability of information from university agriculture extensions.
"Study books and observe nature; if they do not agree, throw away the books." ~ William A. Albrecht
Location: Huntsville Alabama (North Alabama), Zone 7B
Sulfur is the thing to use for long term acidification of soil, only work it into the top six inches of soil for blueberries.
You can use agricultural sulfur or even calcium sulfate (the latter works slower but also adds calcium ions as it breaks down, so if you need calcium it might be a good choice).
I prefer to use Ag. sulfur to get an initial acidification into the soil, (peat is also good at acidifying soil but many are now objecting to using it).
You will also want to add fungi hyphae growth so a mushroom slurry will do a lot for getting that sulfur working as you want it to work.
vinegars would need to be 50% to 58% commercial grade acetic acid and would only work for about 2 weeks, the first rain or watering would leach the acid down below the 12" depth of blueberry bush roots.
Application of such a vinegar would also burn the tender feeder roots.
Vinegars are good for getting rid of weeds in a rock covered commercial landscape site where you want a fast kill.
In a home or garden situation they are a last choice, the rapid acidity kills off bacteria and fungi and all the other organisms you want alive in your soil.
I have used 56% acetic acid (vinegar) on some beds being developed, it worked out there since I was killing off everything and starting fresh.
I will not use it any longer because I also killed off all the earthworms (didn't find that out for several weeks and it took rebuilding the soil before they repopulated that area).
I live in the middle of wild blueberry country. They love growing in areas of coniferous forest that have been clear cut and there is wood chips, shreds, branches etc all over the place on top of boggy soil. A few feet thick too, not just a sprinkling.
From my observations picking wild blueberries, hugelculture made from conifers/pines would be blueberry heaven.
But back to your question, yes pine needle mulch works very well. It's not aggressive like industrial acid, and it doesn't add sulfur to the soil.
For what it's worth, last year I got talking to a localcoffee shop that roasts their own coffee. They just bought a new roaster and had to break it in with a batch of beans to condition the thing properly. Since they can't make coffee with the roasted beans, they gave be a sack full which I'll use as a blueberry mulch / soil acidifier / slow release fertilizer.
Unless you are wanting to get specific species into your soil, it really doesn't matter what type of mushrooms you use to make your slurry.
I typically use what ever I find on our farm when I walk through the woods (over half of Buzzard's Roost is left untouched).
If I want a specific species of fungi I tend to use Paul Stamets' products, not that there aren't other great products out there but I trust Paul explicitly to provide me what I am in need of.
My own normal slurry tends to have about 7 species blended together, I also dilute my slurry to double the amount so I can cover more area with a single slurry making.
Blueberries are bacterial plants. It has been found in the last three years though, that bacteria work in unison with fungi which makes the whole system work better.
It isn't that you need fungi for good blueberries, it is just that fungi do seem to help since they allow a communication network via the intersections of hyphae serving as a highway for bacteria to travel along.
But now we are getting into that realm of my current PHD work and this is not the time for that.
Thanks for the guidance Redhawk. Your current work does sound interesting. I hope you give us more lessons! Maybe book #2.
If there is a chance to pre-order your book let us know. Maybe extra $ to get an autographed edition.
Plant a seed and see if it grows. Some seeds do not grow well but others grow beyond your expectations.
Why does your bag say "bombs"? The reason I ask is that my bag says "tiny ads" and it has stuff like this:
Switching from electric heat to a rocket mass heater reduces your carbon footprint as much as parking 7 cars