If I understand what you want the following should do the trick:

use strict;
use warnings;

my @numbers = map {$_, $_} (4, 7, 11, 14);
my @breads  = split '', 'wrifirwf';
my @parts;
my $breadIndex = $#breads;

while (@numbers) {
    push @parts, $breads[$breadIndex = ($breadIndex + 1) % @breads];
    push @parts,shift @numbers;
    push @parts,$breads[$breadIndex = ($breadIndex + 1) % @breads];
}

print join ' ', @parts;
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Prints:

w 4 r i 4 f i 7 r w 7 f w 11 r i 11 f i 14 r w 14 f
[download]

The key is to recycle the breads using the modulus operator to wrap the bread index.