The default is what you set it to on the settings page. When first installed, the defaults are Gutmann for file erasing and 1-pass pseudorandom data for free space erasing.
In point of fact, Gutmann is serious overkill for any erasing task, particularly on today's hard drives. The authority for this is none other than Peter Gutmann himself, who actually said in the 1996 article in which he described his (theoretical) method, that a few passes with random data was "probably the best one can do". More recent work, which as far as I know has not been challenged, indicates that even a single pass is sufficient to make even data whose location on the drive is known to all intents and purposes non-recoverable. I use the HMG IS5 (3 pass) method for file erasing and the single pass for free space erasing.
David
