At 170 Grammi in Surry Hills, every red-base pizza starts the same way: a tin of San Marzano tomatoes, crushed by hand, with nothing added. No sugar, no herbs, no thickener. The reason is simple — when the tomato is right, it doesn’t need help.
San Marzano is one of those names that gets printed on a lot of tins, not all of which are telling the truth. Here’s what San Marzano tomatoes actually are, why they’re protected by law in Italy, and what they’re doing on the pizzas that come out of the oven on Crown Street.
What Are San Marzano Tomatoes?
San Marzano is a variety of plum tomato grown in the volcanic soils of the Sarno River valley, near Naples, in the Campania region of Italy. Long, thin, and pointed compared to a standard Roma tomato, San Marzano tomatoes have a thinner skin, fewer seeds, and a flesh that’s denser and less watery than most plum varieties.
That density matters more than it sounds. Less water means less dilution — the flavour is concentrated rather than spread thin. San Marzano tomatoes are also naturally lower in acidity and higher in sweetness than many other tomato varieties, which is why a sauce made from them can taste rich and rounded without needing sugar to balance it out.
The DOP Difference
Not every tin labelled “San Marzano” is the genuine article. The real thing — Pomodoro San Marzano dell’Agro Sarnese-Nocerino DOP — is a protected designation, governed by the same kind of regulation that applies to Pecorino Romano and Prosciutto San Daniele. We’ve written before about what DOP certification actually means, but the short version is this: the tomatoes have to be grown in a defined geographic area, to a defined standard, and processed in a way that’s been verified rather than assumed.
That certification exists because the name San Marzano became valuable enough to be worth copying. Plenty of tomatoes grown elsewhere — sometimes from San Marzano seed stock, sometimes not — get labelled San Marzano-style, San Marzano-type, or simply San Marzano without the DOP mark. They’re not necessarily bad tomatoes. They’re just not the same tomato, grown in the same soil, with the same guarantee behind it.
Why San Marzano Tomatoes Suit Pizza
A pizza sauce has a narrow set of requirements, and they’re surprisingly hard to meet. It needs to be thick enough not to soak the base, acidic enough to cut through cheese and oil, sweet enough not to taste sharp, and flavourful enough to hold its own under high heat for a short, intense cook. Most tomatoes fail on at least one of these.
San Marzano tomatoes tend to pass on all four. The low water content means the sauce doesn’t need long reduction — crushed, lightly seasoned, and used essentially raw is often the better choice, because it preserves the tomato’s character rather than cooking it into something generic. The balance of acidity and sweetness means the sauce reads as bright rather than sour once it’s gone through a 60-second blast in a 450-degree oven. And because the flavour is concentrated to begin with, a thin layer goes a long way — which matters on a Roman-style base, where the dough is meant to be the headline, not a vehicle for sauce.
San Marzano vs Other Tinned Tomatoes
Walk down the tinned tomato aisle of any supermarket and the choice is overwhelming — Roma, crushed, diced, passata, and a dozen versions claiming some San Marzano connection. The practical differences come down to three things: variety, growing region, and processing.
Roma tomatoes are a different variety entirely — bred for reliability and yield rather than the specific flavour profile of San Marzano. They’re perfectly good tomatoes, and plenty of excellent sauces are built on them, but they tend to be more acidic and watery, which means more reduction time and often more seasoning to compensate.
Tomatoes grown outside the Agro Sarnese-Nocerino area — even from San Marzano seed — won’t carry the DOP mark, and the soil and climate differences show up in the final product. Volcanic soil drains differently and carries a different mineral profile than most other growing regions, and that shows up in the tomato regardless of how careful the farming is.
None of this means a non-DOP tomato can’t make a good pizza. It means the margin for error is smaller, and the kitchen has to work harder to get the same result. Starting with the right tomato removes one variable from a process that already has very few places to hide.
San Marzano Tomatoes at 170 Grammi
The Amatriciana pizza is the clearest example of San Marzano doing the work it’s meant to do — tomato, guanciale, and Pecorino Romano, where the sauce has to stand up to cured pork without disappearing underneath it. The Burrata pizza uses San Marzano the other way around, as the acidic counterpoint to the cream and richness of La Stella burrata and Prosciutto San Daniele. Same tomato, two completely different jobs — which is really the point. A good ingredient doesn’t need to be the star of every dish. It needs to do whatever that dish requires, reliably, every time.
If you want to taste the difference a tomato makes, the easiest comparison is to order both in the same sitting. The contrast between a red-base pizza built around San Marzano and a white-base pizza with none at all tells you more about what the tomato is contributing than either one does on its own — and the full range of both is on the 170 Grammi dine-in menu.
👉 Book a table at 170 Grammi and taste the Amatriciana alongside a white-base pizza to feel the difference San Marzano makes.
Frequently Asked Questions
San Marzano is a variety of plum tomato grown in the volcanic soils of the Sarno River valley near Naples, in Italy’s Campania region. Compared to standard plum tomatoes, they have thinner skin, fewer seeds, denser flesh, and a balance of sweetness and acidity that makes them especially well suited to sauces.
Genuine San Marzano DOP tomatoes — Pomodoro San Marzano dell’Agro Sarnese-Nocerino DOP — must be grown within a defined geographic area, to defined standards, and processed under verified conditions. This protects the name from being used on tomatoes grown elsewhere, even if they come from San Marzano seed stock.
They’re better suited to specific uses, particularly sauces and pizza toppings. Their lower water content and balanced acidity mean less reduction time and less need for added sugar or seasoning. Other tomato varieties, including Roma, can still produce excellent results — they generally just require more work to get there.
Roma and San Marzano are different varieties. San Marzano tomatoes are longer, less watery, and lower in acidity, with a sweeter, more rounded flavour. Roma tomatoes are more widely available and reliable for growers, but tend to be more acidic and watery, often needing longer cooking to concentrate the flavour.
Tinned San Marzano tomatoes, including DOP-certified versions, are available in Australia through Italian grocers and some supermarkets, though genuine DOP tomatoes are less common than tomatoes labelled “San Marzano-style” or “San Marzano-type,” which don’t carry the same certification or growing-region guarantee.
No — many excellent pizzas use other tomato varieties, and white-base pizzas use no tomato at all. San Marzano is one option among several, but it’s a particularly reliable one for red-base pizzas where the sauce needs to be both flavourful and unobtrusive.
San Marzano tomatoes form the base of the Amatriciana pizza, where the sauce balances guanciale and Pecorino Romano, and feature in the Burrata pizza as the acidic counterpoint to the cream-rich burrata and prosciutto.
