Evidence in Funny Places
I'm working on the vinegar recipes in Qimin Yaoshu , and one of the recipes contains a line that offers some useful insight into the wine making business: 至十月中，如壓酒法，毛袋壓出，則貯之。 When it has become the tenth month, press it with a wool bag as if you were pressing wine, and then store it. Seems like I've been on the right track using cheesecloth and nylon bags, although I would like to get a bag made from mohair or something like that eventually.