There are purple raspberries varieties that turn red before turning purple, so that may be what you have. Any pictures of the plants and/or berries? This can also occur naturally when red and black raspberries create hybrids which can result in purple raspberries.

Agree,..I have one called purple Royalty but it's a large berry.

What color are the stems of the second year (fruit producing) canes? There are berry varieties that produce on 1st year canes, but most of the wild black raspberry canes I've seen have green first year canes, and colored second year canes.

Hello,

Thanks for you responses, I took some photos this morning.

As you can see, they are tiny little things. They don't taste like raspberries. An elderly neighbour said that when she was little, they were called 'Blackcaps' and she lived in Southern Ontario about 100 miles SE of this location. I have never heard of that name before.

https://en.wikipedia.org/wiki/Rubus_occidentalis

Yep, I think black raspberries. The fruit is 'hollow'. Blackberries are solid.

Rubus occidentalis is a species of Rubus native to eastern North America. Its common name black raspberry is shared with the closely related western American species Rubus leucodermis. Other names include:

wild black raspberry

black caps

black cap raspberry

thimbleberry

scotch cap

Yes. Black raspberries not purple raspberries.

Ripe when they go from purple to black.