Semi-rigid silicone closable container

A method of using an closable container, the method comprising:

• (a) receiving a crude oil through an opening in an interior chamber of a tube of the closable container, the closable container being at least partially composed of silicone;
• (b) performing winterization of the crude oil, the winterization including at least:
• (1) mixing the crude oil while it is in the interior chamber with ethanol;
• and
• (2) placing the closable container in a cold environment of between minus 15 degrees and minus 25 degrees Celsius for a period of time that is between 24 and 48 hours, the winterization causing substances in the crude oil to at least one of coagulate or solidify;
• (c) filtering out at least one of a coagulated substance or a solidified substance from the winterized oil;
• (d) performing decarboxylation by heating the filtered and winterized oil to a temperature and for a duration sufficient to remove 99% of the ethanol from the oil;
• and
• (e) mixing one or more additives to the oil to achieve a finished product suitable for shipping in the closable container.

An closable container comprising:

• (a) a semi-rigid tub that is composed of at least 90 percent silicone and that includes at least:
• (1) a base wall, including a floor of the tub;
• (2) one or more side walls defining a junction with the base wall and extending from the junction to a rim, the one or more side walls including one or more interior surfaces that together with the floor define an interior chamber of the tub, the junction defines a band circumscribing the tub that has a thickness that is at least twice as great as a thickness of at least a portion of the one or more side walls;
• and
• (3) at least one window formed in at least one side wall of the one or more side walls that is at least one of at least partially transparent or translucent;
• and
• (b) a semi-rigid lid composed at least partially of silicone and configured to sealingly mate with the one or more side walls via the rim, the lid configured with a channel for insertion of the rim in the channel.