So this is my first year working from grapes since I am fortunate enough to now be stationed in central California and the gettin's good here! So yesterday I picked up about 100# of chardonnay from down in the central valley. It's testing at almost 30 brix with a pH about 4.0. So using the online calculator at vinoenology.com it looks like the 6 gallons of juice I have I need to add 1.7 gal of water to get the brix down to 24. I pressed yesterday evening, and my homebrew store isn't open until tomorrow, so I won't be able to buy tartaric acid until then (and add tomorrow evening, nearly 48 hours after pressing and 60 hours after picking). Is this an acceptable course of action or am I royally hosed at this point? Of course I want a balanced chardonnay, but do I eat it now and adjust the acid after fermentation or hold the yeast until I can adjust the acid?