Jangchub wrote in
:

'Brandywine' tomatoes are heirloom so will come true from seed.
I won't go into the whole process here, but the seeds need to be
fermented after you remove them from the fruit. Just do a quick
search on seed saving tomato seeds and you will find a ton of
helpful information. Fermentation is a vital step in the
process and it's not very difficult.

i run mine through my tortoises... they enjoy a treat of tomato gel
& i get prefertilized seeds (actually i pick the sprouted seedings
out of the soil in the tortoise pens. no need to handle the
droppings).
otherwise, yes, fermentation of the gel helps, but it's not
necessary. i've just dried seeds & grown them the next year.
lee