I purchased 180# each of west coast malbec, merlot, and zinfandel this fall. I inoculated with Red Star Premier Rouge and initial fermentation went as expected. I did a light press and have ~35 gallons of wine in carboys. I started a 2nd run from the pomace of all 3 -- fermented as separate batches, using Wal-Mart brand sugar. When each batch dropped below 1.010 I did a light press to get 5 gallons of wine. All 3 went together into a 54 liter demijohn and a spare gallon. I hard pressed the remaining pomace and got an addition 7 gallons, which I kept separate from the free run/light press. The first runs are kept as varietals while the second runs are homogenized into 1. Here's the oddity -- the first run wines all fermented down to 0.994 to 0.996, as expected. No problems here. All containers of the second run fermented to 1.000 and stopped. I added EC-1118 to kick start the wines with no change. Temperature remained fairly stable so that doesn't appear to be the problem. Each of the containers is at least somewhat different -- demijohn is mostly malbec and merlot wtih some zin. The spare gallon is all zin. Of the hard press, the carboy is almost totally malbec and merlot, and the extra gallons are zin. Yet each fermented to exactly 1.000. I brain stormed with guys at my local shop and the only thing we could think of was non-fermentable sugars. So, does anyone have any idea if cheap sugar (Wal-Mart brand) has more unfermentable sugars in it than name brands, and does anyone have any other ideas regarding the source of the problem? This is curiosity on my part. If the SG remains the same at bottling time I'm going to stabilize. Both the free run and hard press taste good for green wines so I'm fine with making no changes.