Sumac Ridge Estate Winery (pre-2015) is Not Vegan Friendly

Company email (January 2016):
"The only ingredients in the majority of our wines are Grapes and Yeast. Sulfur is added during the crushing to control micro-organisms. The exception is our sparkling wines to which we add standard white sugar to start a secondary fermentation.
We use Diatomaceous clay as a fining agent on all of our wines."

[Given the difference in answers, we're assuming a production change between 2012 and 2016]

Company email (October 2012):
"For clarification purposes only, we use casein (milk protein) on our wines."