I’ve had a few emails this week about the column I wrote in the Sunday Star-Times about my attempt to make tomato sauce that tastes just like the red stuff. Here’s the story (including the recipe) if you missed it:

It went down like an episode of Breaking Bad. Having made contact with a sympathetic small-town pharmacist, I sidled up to the counter and was handed a paper bag containing a disposable plastic syringe and a small bottle of acetic acid.

I went home, donned a pair of latex gloves, sterilised my stainless steel jam pan, sharpened a knife and embarked on an afternoon of bloody carnage. Obviously I wasn’t cooking a batch of crystal meth but something equally addictive: homemade Wattie’s Tomato Sauce.

In our house, nothing is safe from it. Not a sausage (especially a sausage). Not steak and chips. Not mince on toast. Not bacon and eggs. Not mashed potato nor fried rice nor pasta, including free-range fettuccine from the ovaries of our own chooks.

My husband and children go through a large bottle of Wattie’s Tomato Sauce every week. They are ferociously brand loyal. Not only does Heinz have no place in our home, every time I’ve tried to fob them off with homemade ketchup, they’ve shown a distinct lack of enthusiasm.

These days, you can find recipes for almost anything on the internet, from Coca Cola to Colonel Sanders’ 11 secret herbs and spices (paprika, onion, celery salt, sage, garlic, allspice, oregano, chilli, black pepper, basil and marjoram, apparently). But on the subject of Wattie’s Tomato Sauce, the world wide web was all but silent.

My search took me deep into the archives of foodlovers.co.nz, where, at 10.59pm on Thursday 7 February, 2008, a lady named Diane shared her half-century-old method with a glowing endorsement: “This IS like Wattie’s and is pure tomato!”

I weighed out Diane’s ingredients on a set of vintage imperial Salter scales: 12lb tomatoes, 2lb sugar, 3oz whole allspice, 3oz salt and 1.5oz glacial acetic acid from the chemist.

The method was just 16 words long: “Boil all except acid for 3 hours then put through blender/mouli. Add acid and bottle.”

Now for a quick chemistry lesson: acetic acid, which Wikipedia hilariously warns against confusing with the ascetic pursuit of abstinence from worldly pleasures, is the compound that makes vinegar smell sharp and taste sour. The acetic acid in vinegar comes from ethanol fermentation – white vinegar is made from leftover lactose from the dairy industry, malt vinegar from barley, cider vinegar from apples, balsamic from grapes, and so on – and is up to 5 per cent acetic acid, whereas glacial acetic acid is 99 per cent pure.

Why this matters, I have now learned, is that when you make sauces and chutneys with vinegar, it takes hours to boil off all that extra liquid, resulting in a dark brown sauce rather than a sea of red. But if you deseed the tomatoes first (the seeds and gel-like pulp also turn brown when boiled for any length of time), and add only two small spoonfuls of acetic acid as opposed to an entire bottle of vinegar, the sauce retains all of its colour and concentrated tomato flavour.

You must, of course, begin with only the beefiest, beautiful tomatoes. I acquired four crates of ‘Spanish Red’tomatoes from Curious Croppers in Clevedon – horticulturists to the stars, or at least the stars of the Auckland restaurant scene. I sliced each meaty tomato in half, plunging my fingers deep into their blood-red flesh and squeezing sensuously until the seedy pulp ejaculated into a bowl (strain and save the juice for Bloody Marys).

I also tinkered a bit with Diane’s recipe, halving the amount of salt and glacial acetic acid (history tells me that Digby Law and his ilk were rather more fond of vinegar than our modern palates) and adding a tablespoon of citric acid just before bottling in hot jars.

Then I assembled a panel of experts for a blind taste test. My husband, self-confessed sauce connoisseur, couldn’t tell the difference, though the kids remained suspicious until I decanted my DIY version into an empty Wattie’s sauce bottle.

“Profit is sweet,” said Sophocles, “even if it comes from deception.”