Currents & Spice

Stock, both animal and vegetable, is a cornerstone of cooking and is largely believed to have followed the discovery of fire. Once we began cooking, we developed a strategy for boiling every last calorie out of food that we had spent a vast amount of time and energy collecting.

Stock is universally recognised as the basis of a good bowl of soup. Despite this, stock making at home largely fell out of fashion in the western developed world after World War II, when products that simplified cooking such as stock cubes were perceived to be modern and aspirational. As a consequence, many Gen X and Millennial kids more than likely grew up eating soup that lacked depth and was generally relegated to being an entrée.

It doesn’t have to be that way.

The Freezer Bag Habit

Making stock is simple and a simple habit can mean it largely comes from your (and your butchers’) scraps, rather than something that you spend extra money on.

The first step to making stock is to stop throwing things away. Onion skins, celery tops, carrot tops and garlic offcuts all go into a bag in the freezer. So do leftover bones and carcasses. This bag gives you the base to make stock, along with a chicken carcass bought from your butcher, generally for around $2 a bag.

Why stock is better than stock cubes

While stock cubes attempt to mimic the taste of stock, they miss several important taste and texture elements that result in a fuller bodied soup, including:

• Gelatin, which gives the soup body. Gelatin provides viscosity and mouthfeel that is not possible to achieve without boiling the bones and ligaments of an animal. Stock cubes cannot deliver this — there is no shortcut for collagen breakdown.
• Glutamates, which are the G in MSG and deliver a level of umami and savoury depth in the base of the soup. Stock cubes do contain glutamates — often MSG directly, or yeast extract — which is why they can approximate savoury depth. But without gelatin, the result is flavour without body.

These two compounds, along with the fact that the base of the soup is already developed through long cooking and multiple flavour profiles from aromatics and bones, means that you are starting from a nourishing base, rather than salty and oddly flavoured water.

A base stock recipe

This is base stock: it is neutrally flavoured, which means it can be made in bulk, frozen and used for a range of dishes: from a Vietnamese pho to an Italian risotto. It is based on:

• Chicken bones / carcass, which provides the collagen, which in turn breaks down into gelatin during long cooking.
• The fab four vegetable base: onion, celery, carrot and garlic. These four feature across cultures as the base for savoury dishes, with:
  • Onion skins providing savoury and sweet notes, along with colour.
  • Celery tops and the gnarly tough bits providing bitterness, along with phthalides that contribute a subtle umami.
  • Carrot tops and skins that provide sweetness.
  • Garlic offcuts, that provide pungency and additional umami.

You will notice that this recipe lacks salt. This is purposeful and common in professional kitchens. It allows you to salt the dish later and to reduce or add other ingredients (e.g., fish sauce, soy sauce) that contain salt, without the dish becoming too salty. While salt is essential for flavour, it is very hard to neutralise when you have too much.

Making the Stock

What you need

• 2 chicken carcasses (your butcher will sell these for around $2 a bag)
• 3 large handfuls of frozen vegetable scraps fab four
• Any additional saved bones from your freezer
• 2.5 – 3 litres of cold water.

Method

1. Place the carcasses, saved bones and vegetable scraps into your pressure cooker. Add cold water until everything is covered. Starting with cold water draws impurities out of the bones gradually rather than seizing them in, which is what hot water does.
2. Seal the pressure cooker and bring to full pressure. Cook for at high 2 hours.
3. Release the pressure and strain the stock through a fine sieve into a large container.
4. Leave the stock to cool to room temperature, then refrigerate overnight.
5. The next morning the fat will have solidified into a pale layer on top of the stock. Scrape it off cleanly with a spoon.
6. Pour the stock into freezer bags in portion sizes that suit how you cook — 500ml is a useful standard. Freeze flat, stack when solid. Keeps for 3 months.

This will give you a base for a range of dishes, including soups, braises, risotto, and noodle broths, with limited cost and limited effort. It also tastes divine by itself, particularly if you’re feeling poorly. And when you ladle it out, it is worth remembering what it is: onion skins, carrot tops, celery offcuts and a couple of dollars worth of bones: the scraps that every generation before the convenience food era would have considered too valuable to waste.

Myths worth busting

You need to add vinegar to extract more gelatin

This one circulates endlessly in bone broth content. The claim is that acid helps draw collagen out of the bones. The science is genuinely mixed — acid does help dissolve some minerals from bone, but a tablespoon of apple cider vinegar diluted across 2.5 litres of water creates such a mildly acidic environment that most food scientists consider the effect negligible. You would need a far more acidic environment to make a meaningful difference, at which point your stock would taste sour.

You need to simmer for hours on the stovetop

The pressure cooker reaches around 120°C compared to 100°C on the stovetop. That higher temperature breaks down collagen into gelatin faster and more completely. What takes 4-6 hours on the stovetop takes 2 hours under pressure. You are not cutting corners — you are applying better chemistry.

Stock must be clear to be good

Clarity is aesthetic, not functional. A pressure cooker produces slightly cloudier stock because the agitation emulsifies some fat into the liquid. It tastes identical to a clear stock. The only context where clarity matters is consommé.

Roasting bones first is essential

Roasting bones creates deeper, more complex flavour through the Maillard reaction — the same browning that makes seared meat taste better than boiled meat. It is worth doing if you have the time and inclination. It is not worth doing if you don’t. Better collagen extraction and a good bone ratio will make a more significant difference to your stock than whether the bones were roasted first.