The use of the term pushes my buttons and I wish people would stop and tell us something useful about the tomato
The important consideration with tomatoes is the general type they are:
- Basic slicer - about the size of baseball and tend to be ok with rough handling
- Beefsteak - your big tomato with a thinner skin
- Paste - romas and such, the ones you make sauces with
- Cherry - the small half a bite ones that are very sweet
- Campari - half between a cherry and a slicer but not mealy and very sweet
These are the distinction in tomatoes that make sense, not using the term heirloom, the one other distinction would be colour as the yellow tomatoes tend to much less acidic than the red.
.All heirloom really means is that the tomato is an open pollinated variety and not a hybrid seed and has been grown for some unspecified length of time in the past. There is nothing to say that an heirloom tomato will taste good, in fact many of the old varieties are flavourless and mealy. Heirloom does not mean good, in fact on average a heirloom tomato will be a tomato you do not want use, there is a reason they fell out of fashion and it was not some conspiracy by the big agri-business to kill the tomato.
Heirloom also does not mean organic, there is no reason to expect anything called an heirloom tomato to be organically grown.
Hybrids are developed for a host of reasons, one of them is their ability to manage being handled and shipped, but they are also developed for better flavour and for less mealiness. Many of the organic tomatoes grown are hybrid seeds.
The tomatoes you buy in a supermarket will always tend to less flavourful than ones bought from a grower because of the different length of time between picking and eating of the two tomatoes. The same tomato will taste very different when sold in the supermarket versus fresh off of the vine. When I buy a tomato from Glanford Greenhouses I know it was picked only a couple of hours earlier.
When I lived in Lillooet I used to buy a lot of Fountainview Farm carrots. They were so sweet as to more like a fruit like a peach or nectarine than what we know as carrots. In 2004 I saw one of their 50 pound sacks for sale in Victoria at Fairway, I bought them because I wanted that amazing taste, turns out that in transit and such the sugars turned to starches and it was no longer the same blissful piece of heaven. I can say the same about apricots, my favorite fruit but in my opinion inedible unless picked and eaten off of the tree.
There are literally thousands of different heirloom tomatoes, the majority of which are not great eating. Many of the tomatoes refereed to as heirlooms were deliberately created by someone within the last 70 years, some cultivars people call heirloom are not old at all but very recently developed.
If restaurants want to get fancy, they should tell us the name of the tomato cultivar they are using and not call it heirloom.