I understand that difference between unfermented wort vs. green beer. However the unfermented wort will be green beer in a matter of fractions of hours after your steep process. The pH drop and production of alcohol will wipe out any gains made my unwanted cells in that time surely. If I recall your process has you chilling to pitching temps very quickly.
However, bacteria divides three time faster than yeast, so why risk it? We are dealing with an exponential growth pattern that favors bacteria.
bacteria_cell_count_at_time_t = initial_bacteria_cell_count x 2
(integer(t / 30))yeast_cell_count_at_time_t = initial_yeast_cell_count x 2
(integer(t / 90))Let's look at some numbers.
Yeast cell counts at ninety minute intervals
Time = 90: initial_cell_count x 2
1 = initial_cell_count x 2
Time = 180: initial_cell_count x 2
2 = initial_cell_count x 4
Time = 270: initial_cell_count x 2
3 = initial_cell_count x 8
Time = 360: initial_cell_count x 2
4 = initial_cell_count x 16
Time = 450: initial_cell_count x 2
5 = initial_cell_count x 32
Time = 540: initial_cell_count x 2
6 = initial_cell_count x 64
Time = 630: initial_cell_count x 2
7 = initial_cell_count x 128
Time = 720: initial_cell_count x 2
8 = initial_cell_count x 256
Bacteria cell counts at ninety minute intervals
Time = 90: initial_cell_count x 2
3 = initial_cell_count x 8
Time = 180: initial_cell_count x 2
6 = initial_cell_count x 64
Time = 270: initial_cell_count x 2
9 = initial_cell_count x 512
Time = 360: initial_cell_count x 2
12 = initial_cell_count x 4,096
Time = 450: initial_cell_count x 2
15 = initial_cell_count x 32,768
Time = 540: initial_cell_count x 2
18 = initial_cell_count x 262,144
Time = 630: initial_cell_count x 2
21 = initial_cell_count x 2,097,152
Time = 720: initial_cell_count x 2
24 = initial_cell_count x 16,777,216
If anyone has ever wondered why pitching a large healthy yeast starter is standard practice, the data presented above should give you insight.