It is a primarily a fruit shape distinction, not size. Plum tomato varieties are shaped like ...plums. :) They are more oval, more egg shaped and come in small plums, medium plums, and large plums.

Paste tomatoes generally have a shape that is longer than it is wide, some have pointed ends, and come in all sorts of sizes too.

Internally there are differences too. Plums may have different cavity sizes and number, more seeds, less meat, more juice, etc. than pastes but those all vary from variety to variety.

Some use the two labels interchangeably but plums really are a different tomato.

Dave

Thanks Dave! That is very useful info. I appreciate your taking time to answer a question that you've probably answered many times before.

I guess the tomato that really has me confused is "Teton de Venus".
Have you grown this one? I got the seeds from Sand Hill Pres. Center and they described it as a large, red, heart shaped fruit that can be up to 2 lbs. - listed under their red tomatoes and not their paste tomatoes section.
Tatiana's various comments sum it up to be much smaller - less than 6 oz. and oval with a slight point - a plum shaped paste tomato.

Now I am curious to see what this really looks like.

Does anyone know?

Thanks

Hearts are another totally different class from paste and plums. Never grown it but description are often misleading as they are very subjective. About all you can do is read several descriptions and see what the majority is. :)

From the link below I'd call it heart.

Dave

Here is a link that might be useful: Teton de Venus images

I've grown Teton de Venus and it is a heart and a fairly good one at that. Not known as a paste variety but does have dense flesh with few seeds, please see below.

The fruits of ANY variety can vary in size , for the same variety, from year to year and there are lots of variables as well, such as where grown, the weather that season, how the plants are grown, amendments added and on and on.

Five folks list Teton de Venus in the 2012 SSE YEarbook, for members only, and two of them state the size of the fruits they got:

NY, 24 oz
OH, 10-14 oz
TN, just says large meaty heart
VT, good paste tomato
WI, good tasting paste tomato

And I bet the ones who said good paste tomato are ones that have already switched from conventional paste varieties to using hearts and beefsteaks for sauce, etc.

Just noting that sometimes a paste variety has plum in the title but is also a long one as well, the best example Iknow of is Sarnowski Polish Plum and there are others.

Most of my tomato friends switched long ago from using paste varieties to using dense fleshed beefsteak varieties as well as hearts, of which most are dense fleshed with few seeds, and that's b/c most paste varieties are not all that tasty and b'c many of them are susceptible to both BER ( blossom end rot) as well as Early Blight ( A. solani)

Carolyn