My immediate thought, before reading your comments and upon seeing the photos, was that this is ash. Ash trees grow cankers which have random bark incursions and the wood, when turned wet, oxidises and reddens at the surface. I was therefore surprised to see that it's beech, until I took a closer look at the lower half of the second picture and saw all the medullary flecks, which certainly suggest that it is beech.
Having said that, my instinct is always to turn it in one go because when leaving a piece like this to dry out after initial shaping, it can move so much that it might not be re-workable.
Les