Sourdough BLT Sandwich with Garlic Mayo

Few lunches beat a really good Sourdough BLT Sandwich. Think golden, buttery sourdough bread, crisp bacon, thick slices of ripe tomato, fresh lettuce and a generous layer of homemade garlic mayonnaise. It’s a classic combination, but a few thoughtful touches turn it into something particularly delicious.

What I love about this BLT sandwich with garlic mayo is the contrast in every bite. The toasted sourdough brings a satisfying crunch, the bacon adds savoury richness, and the juicy beefsteak tomatoes give the sandwich freshness and natural sweetness.

Then there’s the mayonnaise. Instead of using it straight from the jar, this version combines Duke’s mayonnaise with freshly minced garlic and a squeeze of lemon juice. The result is creamy, tangy and wonderfully flavourful without overpowering the bacon, lettuce and tomato.

Toasting the sourdough in a cast-iron frying pan with butter gives the bread a beautifully golden finish. It also helps the slices hold up against the juicy tomatoes and generous filling.

This homemade sourdough BLT recipe is ideal for a relaxed weekend lunch, a quick family meal or those days when you want a sandwich that feels a little more special than usual.

With ten slices of sourdough, you can assemble five generously filled sandwiches, making it a great option when you’re feeding family or friends.

Sourdough BLT Sandwich Recipe Overview

Recipe: Sourdough BLT Sandwich with Garlic Mayo
Recipe Type: Lunch / Sandwich
Cooking Method: Stovetop Toasting and Bacon Cooking
Yield: 5 sandwiches, using 2 slices of bread each
Bread: 10 slices sourdough
Bacon: 1 lb thinly sliced bacon
Tomatoes: 2–3 beefsteak tomatoes
Lettuce: 1 head iceberg or green leaf lettuce
Spread: Duke’s mayonnaise, garlic and lemon juice
Toasting Fat: 2 tablespoons butter
Preparation Time: Not specified
Cooking Time: Not specified

Important preparation note: The supplied instructions explain how to toast the bread, mix the mayonnaise and assemble the sandwiches, but don’t include a step for cooking the bacon. The bacon must be fully cooked before assembling the sandwiches unless you’re using a product specifically labelled ready to eat.

Why You’ll Love This Sourdough BLT Sandwich

Golden toasted sourdough: Butter-toasting creates a crisp, flavourful base.
Crispy bacon: A generous amount of bacon adds savoury crunch.
Fresh tomatoes: Thick beefsteak tomato slices make every bite juicy and satisfying.
Crunchy lettuce: Iceberg or green leaf lettuce balances the rich bacon and mayonnaise.
Homemade garlic mayo: Garlic and lemon turn ordinary mayonnaise into a punchy sandwich spread.
Simple preparation: No complicated techniques or specialist ingredients required.
Great for sharing: The ten bread slices make five complete sandwiches.
Classic comfort food: Familiar flavours with a delicious sourdough twist.

Sourdough BLT Sandwich Ingredients

Here are the exact ingredients and quantities from the recipe.

For the Sandwiches

10 slices sourdough bread
2–3 beefsteak tomatoes
1 lb bacon (approximately 454 g), thinly sliced
1 head iceberg or green leaf lettuce
Salt and black pepper, to taste
2 tablespoons butter, for toasting the bread

For the Garlic Lemon Mayonnaise

1 cup Duke’s mayonnaise
2 garlic cloves, minced
1 tablespoon fresh lemon juice

Ingredient note: Duke’s is the specified mayonnaise brand, but a similarly rich, tangy mayonnaise can be used as an optional substitute if it isn’t available locally.

Ingredient Notes and Why Each One Matters

Sourdough Bread

The recipe uses ten slices of sourdough bread.

Sourdough adds a gentle tang and a sturdy texture that works beautifully with juicy tomatoes and generous sandwich fillings.

The butter-toasting step helps create a crisp exterior while preserving a little softness inside.

Duke’s Mayonnaise

One cup of Duke’s mayonnaise forms the base of the homemade garlic spread.

Duke’s is known for its rich, tangy flavour and is popular in Southern American cooking.

For UK readers, a good-quality full-fat mayonnaise is a practical optional alternative if Duke’s isn’t available.

Fresh Garlic

Two minced garlic cloves give the mayonnaise a fresh, punchy flavour.

Finely mincing the garlic helps it distribute evenly throughout the spread.

Lemon Juice

One tablespoon of fresh lemon juice adds acidity and brightens the richness of the mayonnaise.

Freshly squeezed lemon juice gives the spread a clean, lively flavour.

Beefsteak Tomatoes

The recipe calls for two to three beefsteak tomatoes.

These large, juicy tomatoes are ideal for thick sandwich slices.

They bring natural sweetness and freshness to contrast with the salty bacon.

Bacon

One pound of thinly sliced bacon provides the savoury centre of the sandwich.

Thin slices are especially good when cooked crisp, giving each bite a satisfying crunch.

The original method doesn’t specify how the bacon is cooked, so make sure it’s fully cooked before using it in the sandwiches.

Iceberg or Green Leaf Lettuce

One head of either lettuce variety is listed.

Iceberg provides a particularly crisp bite, while green leaf lettuce has a softer, more delicate texture.

Butter

Two tablespoons of butter are used to toast the sourdough in a frying pan.

Butter contributes a rich flavour and helps the bread develop a golden surface.

Salt and Black Pepper

The recipe seasons the thick tomato slices with salt and black pepper.

This simple step helps bring out the tomatoes’ natural flavour.

Equipment You’ll Need

Cast-iron frying pan or another heavy-based frying pan
Large frying pan or suitable cooking equipment for the bacon
Mixing bowl
Spoon or small whisk
Sharp knife
Chopping board
Spatula or tongs
Paper towels, if needed for draining cooked bacon
Serving plates

A cast-iron frying pan is particularly useful for creating an evenly golden surface on sourdough bread.

How to Make a Sourdough BLT Sandwich with Garlic Mayo

The supplied recipe uses a straightforward method: toast the bread, prepare the garlic mayonnaise, slice the vegetables and assemble the sandwiches. I’ve also included the essential bacon-cooking step that was missing from the original instructions.

Step 1: Cook the Bacon

Essential additional step: The ingredient list includes one pound of bacon, but the submitted method doesn’t explain how to cook it.

If using raw bacon, cook it thoroughly according to the product instructions using a suitable frying pan or another appropriate method.

For a crisp BLT, cook until the bacon reaches your preferred crispness without burning.

Set the cooked bacon aside while preparing the other ingredients.

If using ready-to-eat cooked bacon, follow its packaging instructions.
Step 2: Heat the Cast-Iron Pan

Place a cast-iron frying pan over medium heat.

Add the 2 tablespoons butter and allow it to melt.

The butter should melt and begin coating the pan without burning.
Step 3: Toast the Sourdough

Add the sourdough bread to the pan in batches.

Toast each slice until golden brown.

Remove the toasted bread and set aside.

Continue until all ten slices are toasted, distributing the measured butter as needed during cooking.

Chef’s tip: Keep the heat moderate. Sourdough can brown quickly, particularly in a well-heated cast-iron pan.
Step 4: Make the Garlic Lemon Mayonnaise

In a small mixing bowl, combine:
- 1 cup Duke’s mayonnaise
- 2 minced garlic cloves
- 1 tablespoon fresh lemon juice
Stir until smooth and evenly mixed.
Step 5: Prepare the Tomatoes

Slice the 2–3 beefsteak tomatoes into thick rounds.

Season lightly with salt and black pepper to taste.

Keep the slices ready for assembling the sandwiches.
Step 6: Prepare the Lettuce

Wash the iceberg or green leaf lettuce thoroughly.

Drain and dry the leaves.

Tear them into pieces that fit comfortably inside the sandwiches.
Step 7: Spread the Garlic Mayo

Spread the homemade garlic mayonnaise on one side of each toasted sourdough slice.

Cover the bread evenly, using the mayo-side as the inside of each sandwich.
Step 8: Layer the BLT Filling

Place the lettuce on one slice of toasted sourdough.

Add the seasoned beefsteak tomato slices.

Top with the fully cooked bacon.

Repeat for the remaining sandwiches.
Step 9: Close the Sandwiches

Place another sourdough slice on top, mayonnaise-side down.

Press gently to hold the layers together without flattening the filling.
Step 10: Serve Immediately

Serve the sandwiches while the toast is crisp and the bacon is freshly cooked.

Cut each sandwich in half if desired.

Enjoy straight away for the best flavour and texture.

How to Get Crispy Bacon for a BLT Sandwich

The bacon is one of the three defining ingredients in a classic BLT, so it’s worth preparing it well.

Choose Thinly Sliced Bacon

The original recipe specifies thinly sliced bacon.

Thin slices can develop a crisp texture that works particularly well between toasted bread and fresh vegetables.

Cook in Suitable Batches

Try not to overcrowd the pan, as tightly packed bacon may cook unevenly.

Watch the Heat

Excessively high heat can burn the edges before the rest of the bacon is cooked to your liking.

Drain Excess Fat if Needed

Allowing freshly cooked bacon to rest briefly on kitchen paper is an optional way to remove excess surface fat.

Keep It Crisp Until Assembly

Prepare the bacon before building the sandwiches, then add it once the tomatoes and lettuce are ready.

Serve While Fresh

BLTs taste particularly good when the bacon is crisp and the vegetables are cool and fresh.

How to Make Homemade Garlic Lemon Mayonnaise

The homemade garlic spread is what makes this sandwich stand out from an everyday BLT.

Start with Mayonnaise

Measure one cup of Duke’s mayonnaise into a bowl.

Add Freshly Minced Garlic

Stir in two finely minced garlic cloves.

Raw garlic has a stronger flavour than cooked garlic, so the original quantity provides a noticeable garlic kick.

Add Lemon Juice

Pour in one tablespoon fresh lemon juice.

This adds a bright, tangy finish.

Mix Until Smooth

Stir thoroughly so the garlic and lemon are evenly distributed.

Spread on Toasted Bread

Coat one side of each slice so the spread faces the sandwich filling.

Keep It Chilled When Not Serving

Because the spread contains mayonnaise and fresh garlic, refrigerate it promptly when not in use.

Chef’s tip: Finely minced garlic is particularly important here because the spread isn’t cooked.

How to Toast Sourdough Bread for the Best BLT

Toasted sourdough provides the structure and flavour that make this recipe special.

Use Slices That Hold Their Shape

Sourdough with a sturdy crust and even crumb makes a good sandwich base.

Warm the Cast-Iron Pan

The original method calls for medium heat.

Use Butter for Flavour

The two tablespoons of butter help the bread develop a rich, golden finish.

Toast Until Golden

Look for a lightly crisp surface rather than deeply burnt edges.

Cook in Batches

Toast only as many slices as comfortably fit in the pan.

Assemble Promptly

Freshly toasted bread gives the finished sandwich its best texture.

Chef’s tip: If your sourdough slices are particularly thick, keep the heat moderate so the surfaces toast without burning.

The Best Way to Layer a BLT Sandwich

A little care during assembly helps prevent a delicious BLT from turning into a slippery, soggy mess.

Start with Toasted Bread

Place the first sourdough slice on a clean work surface.

Spread the Garlic Mayo

Coat the inside of the bread with the creamy garlic and lemon spread.

Add Crisp Lettuce

Dry lettuce helps keep excess water out of the sandwich.

Layer the Seasoned Tomatoes

Thick beefsteak tomato slices provide a juicy, satisfying centre.

Add the Cooked Bacon

Arrange the bacon evenly so every bite includes some of its savoury flavour.

Close with Mayo-Side Down

Place the second toasted sourdough slice on top with the garlic mayo facing the filling.

Cut and Serve

Cut the sandwich diagonally or in half if desired, then serve immediately.

Expert Tips for the Best Homemade BLT Sandwich

1. Choose Ripe Tomatoes

Good beefsteak tomatoes make a noticeable difference to the finished sandwich.

2. Slice the Tomatoes Thickly

Thick slices provide a satisfying bite and plenty of tomato flavour.

3. Season the Tomatoes

The original recipe specifically includes salt and black pepper for the tomatoes.

4. Dry the Lettuce Thoroughly

Wet leaves can make the toasted bread soggy.

5. Cook the Bacon Properly

Use fully cooked bacon before assembling the sandwich.

6. Toast the Bread in Butter

Butter adds flavour and creates golden edges.

7. Avoid Burning the Sourdough

Medium heat allows better control.

8. Mince the Garlic Finely

Small pieces blend more evenly into the mayonnaise.

9. Use Fresh Lemon Juice

It brightens the rich spread.

10. Spread Mayo on Both Bread Slices

The source instructs you to coat one side of each slice.

11. Don’t Overfill the Sandwich

Distribute the bacon, lettuce and tomatoes evenly among the five sandwiches.

12. Serve Straight Away

BLTs are best while the toast is still crisp.

Common BLT Sandwich Mistakes to Avoid

Using Unripe Tomatoes

Tomatoes with little flavour make the sandwich less satisfying.

Skipping the Tomato Seasoning

A little salt and black pepper help bring out their natural flavour.

Leaving Water on the Lettuce

Wet lettuce can soften the toast quickly.

Using Undercooked Bacon

Always cook raw bacon thoroughly before using it in a ready-to-eat sandwich.

Burning the Butter

Keep the frying pan at a moderate heat while toasting the sourdough.

Using Large Pieces of Raw Garlic

Finely mince the garlic so the flavour spreads evenly through the mayonnaise.

Assembling Too Far Ahead

Tomato juices and mayonnaise can soften the bread over time.

Forgetting Which Side Has Mayo

Place the second slice mayonnaise-side down, facing the filling.

Optional Sourdough BLT Variations

The original recipe is a classic bacon, lettuce and tomato sandwich with homemade garlic mayo. These are optional adaptations.

Avocado BLT

Add sliced avocado for a richer, creamier sandwich.

Spicy Garlic Mayo BLT

Stir a small amount of hot sauce into the mayonnaise for extra heat.

Cheddar BLT

Add a slice of cheddar for a cheesy version.

Turkey Bacon BLT

Use a suitable turkey bacon product as an alternative, following its cooking instructions.

Extra-Lettuce BLT

Add additional crisp lettuce if you prefer a lighter, crunchier filling.

Classic Plain-Mayo BLT

Omit the garlic and lemon for a more traditional mayonnaise spread.

Wholemeal Sourdough BLT

Use wholemeal sourdough for a different bread flavour and texture.

Note: These variations change the original ingredients and may affect the final flavour or texture.

What to Serve with a Sourdough BLT Sandwich

Crisps

A handful of crisps makes an easy classic sandwich accompaniment.

Potato Wedges

Golden potato wedges turn the BLT into a more substantial lunch or dinner.

Tomato Soup

A warm bowl of tomato soup pairs beautifully with toasted sourdough.

Simple Green Salad

A lightly dressed salad keeps the meal fresh.

Coleslaw

Crunchy coleslaw adds a cool contrast to the bacon.

Fresh Fruit

Fresh fruit makes a lighter side for lunch.

On Its Own

With generous bacon, tomato, lettuce and sourdough, the sandwich is satisfying without extra sides.

Serve immediately after assembly for the best contrast between crisp toast, juicy tomato and savoury bacon.

How to Store and Make Ahead Sourdough BLT Sandwiches

The original recipe recommends serving immediately, which is the best way to enjoy the texture.

Storing Cooked Bacon

Cool cooked bacon briefly, then refrigerate promptly in a covered container.

Follow the bacon product’s storage instructions. As general guidance, use properly refrigerated cooked leftovers within approximately 3–4 days.

Storing Garlic Mayo

Refrigerate the garlic mayonnaise in a clean, covered container and handle it with clean utensils.

Because it contains freshly minced garlic, prepare modest quantities and follow conservative refrigerated storage practices.

Preparing the Lettuce

Wash and dry the lettuce ahead if needed, then keep it refrigerated.

Preparing the Tomatoes

Tomatoes generally give the best texture when sliced close to serving.

Storing Assembled Sandwiches

Fully assembled BLTs don’t store particularly well because the bread absorbs moisture from the tomatoes and mayonnaise.

Best Make-Ahead Method

Prepare the cooked bacon and garlic mayo ahead, keep the vegetables separate and toast the bread shortly before serving.

Assemble the sandwiches at the last moment for the best crunch.

Frequently Asked Questions About Sourdough BLT Sandwiches

What is a BLT sandwich?

BLT stands for bacon, lettuce and tomato, the three main fillings in this classic sandwich.

Why use sourdough bread for a BLT?

Sourdough has a distinctive tangy flavour and sturdy texture that work well with juicy tomatoes and crisp bacon.

How many sandwiches does this recipe make?

Ten bread slices make five complete two-slice sandwiches.

What type of bacon should I use?

The original recipe specifies one pound of thinly sliced bacon.

Do I need to cook the bacon first?

Yes. Raw bacon must be cooked thoroughly before being added to the sandwich. The submitted instructions omit that cooking step.

What are beefsteak tomatoes?

Beefsteak tomatoes are large, fleshy tomatoes that are particularly good for thick sandwich slices.

Can I use other tomatoes?

Yes. Choose ripe, flavourful tomatoes that slice well.

Which lettuce is best for a BLT?

The original recipe allows iceberg or green leaf lettuce.

Why toast the sourdough in butter?

Butter adds flavour and helps the bread develop a golden, crisp surface.

Do I need a cast-iron frying pan?

No. The original recipe specifies cast iron, but another heavy-based frying pan can work.

What is in the garlic mayo?

One cup of Duke’s mayonnaise, two minced garlic cloves and one tablespoon fresh lemon juice.

Can I use another mayonnaise brand?

Yes. Duke’s is specified in the source, but another full-fat mayonnaise is a practical alternative.

Can I make the garlic mayo ahead?

Yes, if you refrigerate it promptly and handle it safely. Fresh garlic mixtures should not be left at room temperature.

Should I season the tomatoes?

Yes. The original method specifically calls for salt and black pepper.

Should the lettuce be torn or chopped?

The source suggests washing and tearing it into sandwich-sized pieces.

Which side of the bread gets the mayo?

Spread one side of each toasted slice and assemble with the mayo facing inward.

Can I add cheese to my BLT?

Yes, as an optional variation. Cheese isn’t included in the original ingredient list.

Can I add avocado?

Yes. Sliced avocado is a popular optional addition.

How do I stop the BLT getting soggy?

Dry the lettuce, use well-toasted bread and assemble just before serving.

What should I serve with a BLT?

Crisps, potato wedges, soup, coleslaw or a simple salad all work well.

Can I make BLT sandwiches for a picnic?

You can, but keep the prepared ingredients chilled and assemble close to eating time. Bacon and mayonnaise fillings need appropriate temperature control.

Can I freeze an assembled BLT?

Freezing isn’t recommended because lettuce, tomato and mayonnaise can lose their texture after thawing.