Introduction

You’ve done it a hundred times.

Taken a recipe that serves 6, multiplied everything by 10, and ended up with a vat of curry so spicy nobody can eat it. Or a stew so bland it tastes like hot water with beef in it.

However, scaling a recipe isn’t just multiplication. In practice, it’s chemistry.

The good news? Once you know the golden ratios, batch cooking becomes predictable. Consistent. Repeatable.

Here’s your secret sauce.

Cooking times shift:

• Therefore, more volume results in longer cooking times.
• But not proportionally longer (a 10x batch doesn’t take 10x time)
• As a consequence, texture changes if you overcook trying to get “done”.

For this reason, this is why that 6-portion family recipe becomes a disaster at 60 portions. The maths worked. The chemistry didn’t.

Most importantly, The Golden Ratios What Actually Scales

Professional caterers and canteen chefs know these rules. Now you will too.

Rule 1: Proteins & Vegetables Scale Linearly

✅ Multiply directly:

• Beef, chicken, pork, fish
• Vegetables
• Pasta, rice, potatoes
• Dairy (cream, milk, cheese)

Example:
Recipe calls for 500g chicken for 6 people?
For 60 people: 500g × 10 = 5kg chicken

In simple terms, this one is straightforward. You need 10x the main ingredients for 10x the people.

Rule 2: Spices & Seasonings Scale to 75-80%

❌ Don’t multiply directly

According to professional large-scale cooking guidance, spices and seasonings should only increase by 75-80% of the mathematical scaling factor.

For this reason, spices compound in larger volumes. The flavour becomes exponentially stronger, not linearly stronger.

Example:
Recipe calls for 2 tsp chilli powder for 6 people
Mathematical scale for 60 people: 2 tsp × 10 = 20 tsp
Actual amount needed: 20 tsp × 0.75 = 15 tsp

Spices to watch:

• Chilli, cayenne, hot pepper (scale to 70-75%)
• Black pepper, white pepper
• Garlic powder, onion powder
• Dried herbs (thyme, oregano, basil)
• Curry powder, garam masala
• Ground spices (cumin, coriander, turmeric)

Rule 3: Salt Scales to 80-85%

However, salt behaves differently from other spices.

In larger volumes, it dissolves more evenly and tastes more prominent. You need less than you think.

Example:
Recipe calls for 1 tsp salt for 6 people
Mathematical scale for 60 people: 1 tsp × 10 = 10 tsp
Actual amount needed: 10 tsp × 0.80 = 8 tsp

Pro tip: For this reason, always under-salt batch cooking.. You can adjust at service. You can’t remove excess salt.

Rule 4: Fresh Aromatics Scale to 90-95%

Fresh garlic, onions, ginger, and fresh herbs scale almost linearly, but slightly less than proteins.

Why? Meanwhile, fresh aromatics release flavour compounds that concentrate during long cooking.

Example:
Recipe calls for 3 cloves garlic for 6 people
Mathematical scale for 60 people: 3 cloves × 10 = 30 cloves
Actual amount needed: 30 cloves × 0.90 = 27 cloves

The Scaling Factor Formula

Here’s your basic calculation:

Scaling Factor = New Yield ÷ Original Yield

Example:
Original recipe serves 6
You need to serve 60
Scaling factor = 60 ÷ 6 = 10

Then apply the golden ratios:

Applying the Golden Ratios A Worked Example

To illustrate this, let’s take a classic Irish stew recipe. and show you exactly how to scale it properly.

Start with a family-sized recipe (serves 6) from BBC Good Food’s Beef & Guinness Stew or Bord Bia’s Braised Beef in Irish Stout.

Your scaling task: Take it from 6 portions to 60 portions (scaling factor = 10).

How to Apply the Golden Ratios:

Step 1: Identify ingredient types

• Proteins & vegetables → scale × 10 (full mathematical scale)
• Fresh aromatics → scale × 9 (90%)
• Spices & dried herbs → scale × 7.5 (75%)
• Salt → scale × 8 (80%)
• Braising liquids → scale × 9 (90%)
• Thickeners → scale × 8.5 (85%)

Step 2: Calculate each ingredient

If the original recipe calls for:

• 800g beef → 800g × 10 = 8kg beef ✅
• 2 onions → 2 × 10 = 20 onions ✅
• 3 carrots → 3 × 10 = 30 carrots ✅
• 3 cloves garlic → 3 × 9 = 27 cloves garlic (not 30)
• 2 tbsp tomato purée → 2 × 10 = 20 tbsp ✅
• 2 tbsp flour → 2 × 8.5 = 17 tbsp (not 20)
• 500ml Guinness → 500ml × 9 = 4.5 litres (not 5 litres)
• 400ml beef stock → 400ml × 9 = 3.6 litres (not 4 litres)
• 2 bay leaves → 2 × 7.5 = 15 bay leaves (not 20)
• 1 tsp dried thyme → 1 × 7.5 = 7.5 tsp (not 10)
• 1 tsp black pepper → 1 × 7.5 = 7.5 tsp (not 10)
• 1½ tsp salt → 1.5 × 8 = 12 tsp (not 15)

See the difference?

If you’d multiplied everything by 10:

• Thyme: 10 tsp instead of 7.5 tsp (33% too much → overpowering)
• Salt: 15 tsp instead of 12 tsp (25% too salty)
• Liquids: 5 litres Guinness instead of 4.5 litres (too thin, requires longer cooking)

These differences are the difference between “tastes like Mam’s stew” and “tastes like canteen food.”

In addition, Where to Find Great Recipes to Scale

In other words, don’t reinvent the wheel.Start with proven Irish recipes from reputable sources:

Irish Recipe Sources:

Bord Bia Recipes

• Official Irish Food Board recipes
• Traditional and modern Irish dishes
• Quality Irish ingredients focus
• Categories: beef, chicken, pork, seafood, vegetarian

BBC Good Food – Irish Recipes

• Tested, reliable recipes
• Clear instructions
• Irish classics (stews, soda bread, boxty)
• User ratings and reviews

Donal Skehan Recipes

• Irish chef with professional expertise
• Modern takes on traditional dishes
• Detailed method and timing

Irish Examiner – Batch Cooking Features

• Irish food columnists
• Practical batch cooking advice
• Seasonal Irish ingredients

Pro tip: Choose recipes with:

• ✅ Braised or stewed dishes (forgiving, improve with time)
• ✅ Sauce-based dishes (won’t dry out)
• ✅ Simple ingredient lists (easier to scale accurately)
• ❌ Avoid delicate dishes requiring precise timing

Top 3 “Forgiving” Batch Recipes for Irish Canteens

Fortunately, some dishes scale beautifully. Others are nightmares. Here are three categories that hold hot, reheat well, and forgive timing errors.

1. Beef & Guinness Stew (The Gold Standard)

Why it’s forgiving:

• ✅ Improves with long cooking (collagen breaks down)
• ✅ Holds hot for hours without drying out
• ✅ Reheats perfectly the next day
• ✅ Flavours meld and deepen over time
• ✅ Can be held at 80°C for service without texture loss

Scaling notes:

• Brown beef in batches (don’t overcrowd the pan)
• Use the 90% liquid rule (it’s a braise)
• Add extra carrots and onions if needed for bulk
• Consider adding parsnips, turnips, or pearl barley

Where to find recipes:

• BBC Good Food Beef & Guinness Stew
• Bord Bia Braised Beef in Irish Stout
• Donal Skehan Irish Beef Stew

Service tip: Holds beautifully in a bain-marie or hot cabinet for 2-3 hours. Stir occasionally.

3. Slow-Braised Pork Shoulder (Irish Style)

1. Why it’s forgiving:

   • ✅ Nearly impossible to overcook (the fat keeps it moist)
   • ✅ Shreds easily for portion control
   • ✅ Holds hot indefinitely (it’s already braised to falling-apart)
   • ✅ Works hot or cold
   • ✅ Very economical for large numbers

   Scaling notes:

   • Season pork generously (it’s a dense protein)
   • Liquid can be reduced (pork releases its own fat and moisture)
   • Cook whole shoulders, then shred for service
   • Pairs well with apple sauce, colcannon, or mashed potatoes

   Where to find recipes:

   • BBC Good Food – Pork Recipes
   • Bord Bia Pork Recipes

   Service tip: Shred pork and hold in its own braising liquid. Stays moist for hours.

On the other hand, some recipes don’t work at scale. Don’t learn this the hard way.

❌ Delicate Pasta Dishes (Carbonara, Aglio e Olio)

Problem: Timing is critical. Pasta overcooks. Sauce breaks. Cheese clumps.
Alternative: Pre-cook pasta, shock in cold water, reheat à la minute with sauce.

❌ Soufflés, Meringues, Delicate Baking

Problem: Requires precise oven temperature and timing for multiple batches.
Alternative: Don’t offer these in high-volume service.

❌ Fried Foods (Battered Fish, Tempura)

Problem: Goes soggy quickly. Can’t be held hot without quality loss.
Alternative: Cook to order, or offer grilled/baked alternatives.

❌ Rare/Medium-Rare Steaks

Problem: Can’t hold at temperature without overcooking.
Alternative: Sear to order, or offer braised/slow-cooked meats instead.

❌ Dishes Relying on Fresh Herbs Finishing

Problem: Fresh herbs lose colour and flavour when held hot.
Alternative: Add fresh herbs at service, not during cooking.

3. My Kitchen Calculator

Link: https://mykitchencalculator.com/recipeconverter.html

What it does:

• Converts between measurement systems (metric/imperial)
• Scales recipes up or down
• Handles complex recipes with multiple components

Best for: Metric-to-imperial conversions alongside scaling.

Pro tip: Use the calculator for baseline numbers, then apply your golden ratios (75% for spices, 80% for salt, etc.) manually. The calculators don’t know the chemistry rules.

Most importantly, Practical Batch Cooking Tips for Canteen Service

In addition, beyond scaling, here’s what makes batch cooking work. in real-world service:

1. Cook in Stages

Don’t try to cook 60 portions in one go if your equipment can’t handle it.

Example: For 60-portion stew:

• Cook in 2× 30-portion batches
• Or 3× 20-portion batches

Smaller batches cook more evenly and are easier to manage.

2. Use Weight, Not Volume

Volume measurements (cups, spoons) are inconsistent at scale.

Switch to weight:

• 1 cup flour ≈ 120g
• 1 tsp salt ≈ 6g
• 1 tbsp oil ≈ 15ml

Weigh everything. It’s more accurate and faster.

3. Most importantly, taste as you go.

The reality of rodent behaviour:

• Mice are territorial – seeing one means there are 10+ hidden
• Rats are nocturnal – you only see 5% of the population
• Breeding cycle: mice can have 6-10 litters per year, 5-6 babies each
• By the time you see signs regularly, you have an infestation

One sighting is not “no big deal.” It’s an early warning you’re ignoring.

4. Write It Down

When you get a scaled recipe right, document it.

Record:

• Exact weights of all ingredients
• Cooking times for your equipment
• Holding times and temperatures
• Any adjustments you made
• Customer feedback

Build your own canteen recipe book. Next time, you’ll nail it first try.

5. Plan for Holding Time

Most canteen dishes sit hot for 30 minutes to 2 hours before service.

Test your recipes for holding:

• Cook a batch
• Hold at service temperature (75-80°C)
• Check texture, moisture, flavour every 30 minutes

If it dries out or toughens, it’s not a good batch recipe. Adjust or choose something else.

The Temperature Safety Rule

Most importantly, batch cooking isn’t just about flavour. It’s about food safety.

HACCP principles for batch cooking:

Cooking:

• Core temperature must reach 75°C minimum
• Hold at that temperature for 30 seconds minimum
• Check multiple points in large pots (centre, edges, bottom)

Holding hot:

• Maintain above 63°C at all times
• Check temperature every 2 hours (document it)
• Discard after 4 hours of hot holding (quality and safety decline)

Cooling for reheat:

• Cool from 75°C to 21°C within 2 hours
• Then from 21°C to 5°C within 4 hours
• Use shallow containers, ice baths, blast chillers

Reheating:

• Reheat to 75°C core temperature minimum
• Reheat only once (don’t reheat leftovers multiple times)

Get this wrong, and your scaled recipe doesn’t matter. You’ll be dealing with a food poisoning outbreak instead.

Your staff need to understand these critical temperatures. However, this is where proper food safety training becomes non-negotiable. Level 1 Food Safety training covers temperature control, safe holding times, and HACCP basics for all kitchen staff.

When to Call in a Professional Recipe Developer

Some operations need custom-scaled recipes developed by professionals.

Consider professional help if:

• You’re scaling recipes beyond 100 portions regularly
• You’re launching a new canteen operation from scratch
• You need recipes for commercial cook-chill production
• You’re struggling with consistency across multiple sites
• You need recipes that meet specific dietary requirements at scale

Professional recipe developers understand:

• Industrial cooking equipment behaviour
• Ingredient functionality at volume
• Cost control and margin optimisation
• Nutritional requirements for institutions (schools, hospitals, care homes)

Investment: Typically £500-£2,000 per recipe, but you get a tested, documented, reproducible formula that works every single time.

For high-volume operations, this pays for itself in reduced waste and consistent quality.

For kitchen teams:
Level 1 Food Safety & HACCP training teaches all kitchen staff why procedures matter, including recipe adherence and temperature control.

For supervisors and head chefs:
Level 2 HACCP training covers recipe management, scaling procedures, quality control systems, and how to implement HACCP in batch cooking operations.

You’re still on your break. You have 5 minutes. Do this before you go back to service:

Right now (on your phone):

1. Check your last pest control report – read it properly
2. Check your training records – who hasn’t done food safety training?
3. Make a note of every gap, hole, or broken seal you know about
4. Check when door seals were last replaced

Tomorrow: 5. Walk to Goods Inwards and actually look at it with fresh eyes 6. Take photos of problem areas 7. Ask your porter/delivery staff what issues they see daily

This week: 8. Book door seal repairs if needed 9. Implement immediate cardboard breakdown rule 10. Brief all staff on door discipline 11. Contact your pest control company if gaps were mentioned in reports

This month: 12. Get basic food safety training for porters and delivery staff 13. Add pest checks to opening/closing procedures 14. Fix all ingress points identified in last pest control report