Easy - cook 'em first!! Boil the waste pulp for 15-20 minutes in water, drain well before adding. I made the mistake about 5-6 years ago of adding about a quart of raw tomato seeds/skin that came out of my Villaware strainer when I was canning tomato sauce. OMG... They loved the skin & left pale orange tissue-paper thin remains that easily sifted out - BUT apparently seeds are not on the menu. Although I had sifted my compost pretty well (I THOUGHT!), I had countless tomato seedlings coming up in my cell packs of various other seedlings under lights since I had mixed the vermicompost in with my seed-starter! Also had enough sprouting in my newly re-potted houseplants that spring and for 3-4 years later to supply the whole county! SO be forewarned -- cook any seed waste before adding it to the bin! I don't mind avocados or even the odd squash-type seedling that pops up - they are large & easily dealt with!

Just noticed the date of your post, Mad Dog. Sorry this is just a tad late! So... what did you end up doing with the blackberry pulp?

I threw them out. Next time I will boil them as I know the worms would love the solids.