In organics what is often overlooked is simply letting the soilmix cook. That is, allowing it, after the recipe of amendment have been combined and mixed, to simply sit and stabilize. Usually for thirty days or more, which allows the microlife to reach an equilibrium and balance the soils ph between 6 and 7. So if you haven't already, go ahead and mix the ingredients and allow them to sit and cook, so to speak. Then recheck the ph. If you're using a probe type ph meter the moisture of the soil, whether it's dry or moist when you check can affect the reading. Case in point, this morning it was 45 degrees out and I checked my soilmix and it came out to near 8. But the day before it was 6.6. This evening I checked it again and it was 6.6 at 69 degrees so sometimes a false reading is given due to things like that when dealing with probe type meter like I use. But I knew it hadn't changed that quickly from the day before. Anyhow good gardening.