I think I finally got it. I've removed "defined" as well and left it like that:
<?php if(types_render_field('fw_product_wine_appellation', array('raw'=>'true'))){?>
<dt class="productLabel"><?php echo __( 'Appellation:', 'formulawino' ); ?></dt><dd class="productDescription"><?php echo(types_render_field('fw_product_wine_appellation', array('class'=>''))); ?></dd>
<?php }?>
and it seems to be working. When I clear the field in admin panel the label disappear, when I put something there than it is displayed so I guess this time it worked 
Thanks for the directions.
regards,
Przemek