The organism should be re-incubating to permit it to have additional opportunity to create finished results that might be acidic. It may be the case that there isn't sufficient finished result to change the shade of the Methyl Red yet.Some microbiologists prescribe re-brooding life forms delivering methyl red-negative outcomes for an extra 2 to 3 days to build test sensitivity.
Answer: You can add neutral solutions with a pH of 7, like water. Water will dissolve the alkaline/acidic pH to near 7 and 8, which are safe to drink.
Hope this helps you!
I don't know if this helps or not but you would want to know the age of the rock (absolute dating) and from there you will be able to know the age of the fossil and what caused it to die.