Sustainability and costing: using ingredients and costs wisely
Sustainable cooking sometimes sounds as if you mainly have to buy different products. But in the kitchen, sustainability often begins much more simply: don’t buy more than you need, use as much as possible of what you buy and know what a dish really costs.
That last point is perhaps less exciting than a lovely sauce or a good piece of meat, but it is part of good cooking.
Because if you buy €3 worth of ingredients and end up using only half of it, you don’t only pay for what ends up on your plate. You also pay for what disappears into the bin.
Sustainability and costing therefore have more to do with each other than you might think.
What does sustainability mean in the kitchen?
Sustainable cooking doesn’t mean that every ingredient has to be organic, local or packaging-free.
It is about making conscious choices in which as few raw materials as possible are lost.
Think of:
- not buying more than you need;
- storing food in the right way;
- reusing leftovers;
- using as many edible parts as possible;
- taking season and availability into account;
- looking critically at packaging;
- planning dishes so that ingredients return in several preparations.
In particular, preventing food waste has a big effect. In the Netherlands, on average well over 25 kilos of edible food per person are thrown away every year. That food has already cost raw materials, energy, transport and money before it ends up in the bin.
So sustainable cooking doesn’t only begin with the choice in the supermarket. It begins with your recipe.
What is costing?
With costing you calculate what a dish really costs.
That can be very simple. Suppose you use the following ingredients for a dish:
| Ingredient | Cost |
|---|---|
| Potatoes | €0.80 |
| Carrot | €0.35 |
| Onion | €0.20 |
| Cream | €0.60 |
| Herbs | €0.15 |
| Total | €2.10 |
If you make four portions with this, the dish costs, based on these ingredients:
€2.10 ÷ 4 = €0.53 per portion
That seems simple, and it is.
But a good costing goes further than just the price on the shopping receipt.
Purchase price is not the same as the price you use
This is where things often go wrong in the kitchen.
Suppose you buy a 1-kilo bag of carrots for €2.00.
You use 400 grams for your recipe.
Then you can’t simply count €2.00 as the cost of your recipe.
If you really do use the other 600 grams for other dishes, you should only charge the amount used to the recipe.
In this example:
€2.00 ÷ 1,000 grams = €0.002 per gram
For 400 grams:
400 × €0.002 = €0.80
So the ingredient cost of this recipe is €0.80.
That seems a small difference, but with dozens or hundreds of dishes, such an error quickly adds up.
Allow for trimming losses
Not everything you buy ends up on your plate.
From a cauliflower, for example, you remove leaves and part of the stalk. From a leek you cut off the root end and sometimes part of the green. With meat and fish there may be trimming losses or removed parts.
That is why it is important to distinguish between:
Purchase weight
What you actually buy.
Cleaned weight
What is left after you have cleaned the product.
Usable weight
The part that you actually use in your dish.
We often call that difference the yield of a product.
And that is exactly where sustainability gets interesting.
Waste is not always waste
A part cut off a product is not automatically worthless.
The stalk of broccoli, for example, can be peeled and eaten too. The green part of a leek can go into a soup or stock. Vegetable scraps can be used for a stock or broth, as long as they are clean and fit for consumption.
The Nutrition Centre (Voedingscentrum) also mentions using, for example, broccoli stalks, leek greens and the peel of certain vegetables as a way of using more of a product.
That doesn’t mean you have to keep everything.
It is about learning to look:
Can I still use this, or is it really waste?
That is a much more useful question than simply trying to throw away as little as possible.
From vegetable scraps to stock
A nice example is a vegetable stock.
While cooking you may have small pieces of carrot, leek, onion, celery or herb stalks left over. If they are clean and fit for use, you can collect them and use them later for a stock.
You can, for example, keep them in a sealed container or bag in the freezer.
When you have collected enough, you can make a basic stock from them.
That gives a waste stream a new function.
But note: only keep scraps that are still safe and fit to eat. A product that has spoiled doesn’t belong in a stock after all.
Costing starts with your recipe
A good recipe costing actually begins before you start cooking.
Note down for each ingredient:
| Ingredient | Quantity | Purchase price | Recipe cost |
|---|---|---|---|
| Onion | 150 g | €1.50/kg | €0.23 |
| Carrot | 300 g | €2.00/kg | €0.60 |
| Potato | 600 g | €1.80/kg | €1.08 |
| Cream | 200 ml | €3.00/l | €0.60 |
| Herbs | — | — | €0.20 |
| Total | €2.71 |
If you make four portions, then:
€2.71 ÷ 4 = €0.68 per portion
That is the ingredient cost price of the dish.
What is food cost?
The term food cost is mainly found in professional kitchens.
Food cost looks at the relationship between the cost of the ingredients and the selling price of the dish.
The basic formula is:
Food cost percentage = ingredient cost ÷ selling price × 100
Suppose:
- ingredient cost: €4.00
- selling price: €16.00
Then:
€4 ÷ €16 × 100 = 25%
So in this example the food cost is 25%.
That doesn’t mean that a restaurant makes €12 profit on a selling price of €16.
All kinds of other costs still have to be deducted.
Food cost is not the same as profit
This is an important distinction.
A dish can, for example, also involve costs for:
- staff;
- energy;
- rent;
- equipment;
- cleaning;
- packaging;
- transport;
- depreciation;
- administration;
- taxes;
- waste.
That is why food cost is only one part of the total operating costs.
You can simply see it like this:
Selling price
↓
ingredient costs = food cost
↓
other operating costs
↓
what is ultimately left
A dish with a low food cost is therefore not automatically a profitable dish.
So what is the cost price?
The cost price is a broader concept.
If you bake a cake at home, for example, you can look only at the ingredients.
But if you make that cake commercially, labour, energy, packaging and other costs can also be included.
You then get, for example:
| Costs | Amount |
|---|---|
| Ingredients | €8.00 |
| Packaging | €1.00 |
| Energy | €0.50 |
| Labour | €5.00 |
| Other costs | €1.50 |
| Total cost price | €16.00 |
The calculation thus becomes much more realistic.
Why portion size matters
A recipe can look cheap on paper, but that says little if you don’t know how many portions you get from it.
Suppose:
Total ingredient cost: €12
With four portions:
€12 ÷ 4 = €3 per portion
But with six portions:
€12 ÷ 6 = €2 per portion
That is why a recipe should always make clear how many people or portions it is intended for.
That is handy at home too.
If you regularly cook for two people, a recipe for four can mean you make needlessly much food. Sometimes cooking extra is handy, when you can store the rest well or freeze it. The Nutrition Centre, for example, advises deliberately cooking for several days when that helps to prevent waste.
Buying sustainably: look beyond the price
The cheapest choice is not automatically the most sustainable choice.
But the reverse also applies: a more expensive product is not automatically more sustainable.
With vegetables and fruit, season, growing method, origin, transport, packaging and storage method all play a part. Milieu Centraal (a Dutch environmental information organisation) stresses, for example, that local is not automatically more environmentally friendly. The total environmental impact depends on several factors.
That is why it is wiser not to work with one simple rule.
Look at the whole picture.
Seasonal products
Cooking with seasonal products can have several advantages.
Seasonal vegetables are often readily available and can be good value. Cooking with the seasons also brings more variety to your menu.
In winter, for example, think of:
- cabbage;
- celeriac;
- winter carrots;
- leeks;
- Brussels sprouts.
And in summer:
- courgette;
- tomato;
- green beans;
- pepper;
- various leafy vegetables.
The nice thing is that sustainability here also becomes directly linked to cooking.
If you cook with the seasons, you automatically change ingredients and recipes more often.
Buy what you actually use
One of the simplest ways to prevent waste is also one of the most effective:
first look at what you already have.
Before you go shopping:
- Check the fridge, freezer and store cupboard.
- See which products need to be used up soon.
- Think of dishes in which you can use these products.
- Only then make your shopping list.
- Buy fresh products to fit your plans as far as possible.
Milieu Centraal advises exactly that approach: first look at what is still in the house and then match your shopping to your planning.
That way you avoid shopping for a recipe when the same ingredient is already at the back of the fridge.
Leftovers are not a failure
Half a courgette, a few boiled potatoes or some rice from yesterday needn’t be a problem.
See it as a new ingredient.
A leftover vegetable can, for example, end up in:
- an omelette;
- soup;
- pasta;
- nasi;
- a stir-fry;
- a salad;
- a sauce.
The Nutrition Centre also advises using leftovers as the starting point for a new meal.
A good cook therefore looks not only at the recipe on the menu today, but also at what will still be usable tomorrow.
Storage is part of sustainable cooking
Sustainable cooking doesn’t stop when the food comes out of the pan.
Storing it well is at least as important.
Prepared leftovers should be cooled quickly and put in the fridge or freezer in a sealed container. For many meal leftovers, the Nutrition Centre advises a maximum of two days in the fridge and about three months in the freezer.
A simple system helps:
Cook → cool → portion → date → store
That way you know what is in there and prevent a container from sitting at the back of the fridge for weeks.
Sustainability also begins with the menu
When you make several dishes, you can share ingredients cleverly across different dishes.
Suppose you need carrot for three dishes.
Instead of buying a small amount for each dish separately, you can buy one larger amount and plan how you use it.
For example:
Monday: carrot in soup
Tuesday: roasted carrot as a side dish
Wednesday: carrot in a stew
That way you use an ingredient fully and have to buy fewer different small packages.
This is not only handy for your wallet. It also makes your kitchen more organised.
Costing with waste
This is where sustainability and costing really come together.
Suppose you buy €10 worth of vegetables.
Of that, you end up using only €7 worth of edible parts.
Then you haven’t made a recipe with €7 of vegetable costs.
You have spent €10 to end up with €7 of usable product.
So you shouldn’t just forget the other €3 in your calculation.
You can then investigate:
Can I reduce that €3 next time?
Perhaps by:
- cutting differently;
- buying a different pack size;
- buying smaller quantities;
- using waste streams;
- planning better.
That is costing as a cook really needs it.
A simple example
Suppose you make a vegetable soup.
You buy:
- 1 kg of carrots for €2.00
- 1 leek for €1.00
- 2 onions for €0.60
- stock for €0.80
Total:
€4.40
You use everything except €0.50 worth of vegetable scraps.
If those scraps really can’t be used any more, then for your calculation you should start from the quantities actually used and the yield of your products.
But if you use the vegetable scraps for a later stock, the story changes.
Then those scraps still have value.
So waste is not only a sustainability issue. It is also a costing issue.
The five questions of a sustainable cook
When you buy, use or throw away an ingredient, ask yourself these five questions:
1. Do I really need this?
Don’t buy automatically just because a recipe prescribes it.
2. Do I already have it in the house?
Check the fridge, freezer and store cupboard.
3. How much do I really need?
Adjust your quantity to the number of people eating.
4. Can I use the rest?
Think of soup, sauce, stock, salad or another dish.
5. What does this dish really cost?
Calculate the ingredient costs per recipe and per portion.
Those are simple questions, but together they can make a big difference.
Sustainability and costing at a glance
| Topic | Question you ask yourself |
|---|---|
| Purchasing | What do I really need? |
| Planning | What do I already have in the house? |
| Portions | How many people am I cooking for? |
| Trimming loss | How much of the product do I really use? |
| Waste streams | Can I still use the parts I cut off? |
| Storage | Can I store the surplus safely? |
| Recipe cost | What do all the ingredients cost together? |
| Portion cost | What does one portion cost? |
| Food cost | How do ingredient costs relate to the selling price? |
| Total cost price | What other costs come into play? |
Remember this
Sustainable cooking doesn’t mean that you may never throw anything away or that every ingredient needs a complicated environmental calculation.
It begins much more practically:
Buy consciously. Plan your quantities. Use what you have. Store what is left over. Calculate what your dish really costs.
And perhaps most importantly:
a good costing doesn’t begin at the end of the recipe, but with the first shopping.
When you learn to look at how much you buy, how much you really use and what you can do with the rest, you start to cook differently.
You waste less.
You buy more cleverly.
And you gain more and more insight into what a dish really costs.
That is sustainability that you can apply every day in your own kitchen.