Collected from the trees at my house and got 10L of 4% (after dumping out the ice in the buckets). Removing the ice in my large sap storage container over the past few days has left me with 4% in there as well. Can't get to my other trees due to ice and a fallen tree over the roadway. I'd be quite sure that they are mostly frozen as well so it's not a problem to wait for a day or two more. Mother Nature's the boss.