Hi Smoky, we have steamed elderberries, we got about a gallon of juice from about 10 pounds of berries, "about" is as close as I can get as we never actually kept records for them, just juiced until I got enough juice to do whatever we wanted. The acid levels will be lower for some reason, at least for us it was very low after juicing. If you can get enough elderberries try to make a 100% juice wine, its really worth it. We juice the berries, add sugar to the hot juice to melt it. We let it cool, take an acid reading and then add acid, nutrient, oak and the yeast. I dont usually add KMeta to the steamed juices as its basically sterilized and t he yeast will get a fast start.
TRY IT YOU WILL LIKE IT