I prepared a must for a mead last weekend (recipe below) and after a whole week there has been no fermentation activity. I took a pH reading and it came in at 4.4 - is it likely that the must is simply too acidic for the yeast? I added a teaspoon of CaCO3 and stirred it in - got a small fizz - so will wait and see if that works. Should I re-pitch more yeast?
16L mineral water 4kg cherry blossom honey 4kg peeled, stoned, and pasteurised lychees 11g US-05
I pitched the yeast at 20 degrees, after aerating the cooled must. There's 20L of must in 2x10L fermentors. I added 1tsp of yeast nutrient in each fermentor, along with 1tsp of pectic enzyme and 1tsp of tartaric acid. When fermentation hadn't started after 2 days I prepared a yeast starter with another 11g of US-05 and the starter was fine, so I know the yeast was healthy when I pitched.
Any suggestions gratefully received.