Making a batch of onion bacon jam is one of those Sunday projects that ruins you for condiments forever. We started our first batch thinking it was a quick project. It wasn’t. Four hours in, we were eating it straight off the spoon before the first burger even hit the grill.
The thing about this jam that was important for us was the texture – it needed to be jammy, thick, and still have very intentional bacony bites. We figured out the step after the slow cook was the reduction – simmering it all in a big skillet gave everything a minute to really go from good to, ‘damn, I am making this for every burger night ad infinitum.’
When you take the time to reduce it in a skillet, what you end up with is your new burger topping, sandwich upgrade, band smear-it-on-a-Ritz-and-go snack. It’s mahogany-dark and sweet-savory, with balsamic cutting through the fat and coffee adding just enough bitterness to keep the sugar balanced. Once there’s a jar in your fridge, you’ll find excuses to use it up.
🔪 Ingredients for Onion Bacon Jam
- Thick-cut bacon: slab or strips, cut into ½-inch lardons before cooking. Thickness matters; thin bacon overcooks before the onions are ready and gives you bits instead of chunks. Pop it in the freezer for 15 minutes before cutting to make it easier.
- Yellow onions: large ones, diced fine. Skip sweet onions; they’re already too sweet and lose their structure early.
- Garlic
- Fresh thyme: tied into a bundle so it pulls out cleanly. Don’t skip the bundle step — fishing individual stems out of jam is not fun.
- Dark brown sugar: packed. The deeper molasses content is what builds the mahogany color. Light brown sugar works, but the result is noticeably lighter in both color and complexity.
- Strong brewed coffee: hot or cold. It won’t taste like mocha. Coffee is the bitter agent that cuts through pork fat and sugar and adds depth.
- Bourbon: for deglazing the fond and adding layered sweetness.
- Balsamic vinegar: complex acidity that rounds out the sweetness without sharpness. The tannins work with the coffee to keep the jam savory.
- Apple cider vinegar: a brighter, higher note to balance the balsamic’s depth.
- Pure maple syrup: a different sweetness register than the brown sugar, one that adds a quiet depth in the background.
- Red pepper flakes: optional, but recommended. Just enough to keep the jam from tipping fully sweet.
- Freshly cracked black pepper: coarse grind. Don’t use pre-ground here.
Equipment
- Large skillet or Dutch oven for the initial bacon render and onion cook
- Slow cooker, 6-quart or larger — you need the headroom for all those onions before they break down
- Wide 12-inch skillet for the finishing step — stainless or cast iron, something that holds and distributes high heat evenly
- Wooden spoon or silicone spatula for the drag test
📝 How to Make Onion Bacon Jam
- Freeze the bacon for 15 minutes before cutting. Cold fat cuts cleanly into uniform ½-inch lardons. Warm fat slides and gives you uneven pieces that cook unevenly.
- Render the bacon in batches in a large skillet over medium heat until the pieces are deep brown and crispy, 8–10 minutes per batch. Work in batches – crowding the pan steams instead of renders. Transfer to a paper-towel-lined plate. Reserve 3–4 tablespoons of fat in the pan.
- Cook the diced onions in the reserved fat over medium heat, stirring occasionally, until soft, translucent, and just starting to take on golden color at the edges, 10–15 minutes. Add minced garlic and cook 1 more minute, until fragrant.
- Increase heat to high. Pour in the bourbon and scrape up all the browned bits from the bottom of the pan. Let it bubble hard for 2 full minutes – the alcohol burns off, the fond dissolves into the base, and the smell shifts from sharp to caramel.
- Transfer the onion mixture and crispy bacon to the slow cooker. Add the coffee, balsamic vinegar, apple cider vinegar, maple syrup, dark brown sugar, red pepper flakes, cracked black pepper, and the tied thyme bundle. Stir to combine everything.
- Cook on HIGH for 4 hours or LOW for 6–8 hours. Remove the lid for the last hour of cooking to start releasing moisture.
- Discard the thyme bundle. The mixture will still be loose at this point. The slow cooker built the flavor. The skillet finish builds the texture.
- Transfer everything to a wide skillet over medium-high heat. Cook, stirring constantly, for 20–30 minutes. The drag test is your doneness cue: drag a wooden spoon through the pan – the jam should hold a clear line for a full second before flowing back together. Pull it off the heat at that point.
- For a smoother texture, pulse 2–3 times in a food processor. For chunky (recommended), skip this step. Cool completely before transferring to jars.
🔄 Substitutions
- Yellow onions: red onions work and the color goes nearly purple-dark, which looks stunning on a cheese board but a little off on a burger; white onions produce a sharper, more savory result that reads less sweet
- Bourbon: dark rum or brandy is an easy substitution for bourbon.
- Dark brown sugar: light brown sugar gives you a lighter-colored jam – more amber than mahogany – and the molasses backbone that brings it all together just isn’t as deep; white granulated sugar is a no, the color goes flat, and the complexity goes with it
- Balsamic vinegar: sherry vinegar works and keeps the round acidity; red wine vinegar is sharper, and you’ll notice it; white balsamic is too sweet and too thin – don’t use it.
- Strong brewed coffee: espresso is even better; instant dissolved in hot water works fine; skip it entirely, and the jam is noticeably one-note and overly sweet.
- Fresh thyme: 1 teaspoon dried tied in cheesecloth substitutes cleanly; leaving it out entirely doesn’t ruin the jam, but the finish is flatter, like something’s almost there but not quite. Fresh herbs add brightness that rounds this out.
💡 Meat Nerd Tips
- The skillet finish is not optional. We tested batches straight from the slow cooker. They taste good. They just don’t behave like jam – they pool, spread, and run off everything you put them on. The 20–30 minute stovetop reduction is the step that makes this a spread.
- Trust the drag test, not the clock. Depending on how much liquid your specific onions release and how hard your slow cooker runs, the finishing time can vary by 10 minutes in either direction. The clock is a guide. The spoon dragging across the pan is the actual answer.
- Do not put raw bacon in the slow cooker. We’re texture freaks when it comes to bacon. Raw bacon in a slow cooker produces a greasy, pale, flabby texture that never properly renders, no matter how long you cook it.
- Make a double batch. It freezes perfectly for up to 3 months, and the active work time is nearly identical whether you make one jar or two. The slow cooker does the waiting either way.
🍽️ What to Serve with Onion Bacon Jam
- Spoon it warm onto smash burgers while the cheese is still melting – you will never go back to ketchup
- Melt it over a whole wheel of Camembert until the cheese is melty inside; the whole situation is hard to explain and impossible to stop eating
- Fold into puff pastry, bake until the edges caramelize – Bacon Jam Palmiers (coming soon) take 20 minutes to make and disappear faster
- Ladle over Hasselback potatoes fresh from the oven – think loaded baked potato with pockets for extra toppings
- Pile onto Big Mac Sliders in place of special sauce – the sweetness hits differently against the pickles and feels like the adult upgrade you didn’t know you needed.
- Top crackers with aged cheddar and cornichons – it’s the thing on the charcuterie board everyone asks about
🧊 Leftovers and Storage
- Fridge: store in an airtight glass jar for 2–3 weeks
- Freezer: up to 3 months; freeze in small portions so you can thaw exactly what you need
- Serve: always warm or at room temperature — cold bacon fat has a waxy, unpleasant texture straight from the fridge
- Reheat: gently in a small saucepan over low heat, or microwave in 15-second intervals; if too firm, add a small splash of water or bourbon and stir to loosen
- If it separated in the fridge: totally normal — fat solidifies when cold; warm it up and stir it back together
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Onion Bacon Jam Recipe
Recommended Equipment
- 10-12″ Cast Iron Skillet or other oven safe skillet or Dutch oven
- Wooden spoon or silicone spatula
Ingredients
- 2 lbs thick-cut bacon cut into ½-inch lardons
- 4-5 large yellow onions finely diced
- 4–5 garlic cloves minced
- 1 bundle fresh thyme tied
- 1 cup dark brown sugar packed
- 1 cup strong brewed coffee
- ½ cup bourbon whiskey
- ½ cup balsamic vinegar
- ¼ cup apple cider vinegar
- ¼ cup pure maple syrup
- 1 tsp red pepper flakes optional but we highly recommend
- Freshly cracked black pepper to taste
Instructions
Prep the Bacon
- Freeze bacon 15 min, then cut crosswise into uniform ½-inch lardons (pieces).
Render the Bacon
- Cook in batches in a large skillet over medium heat until deep brown and crispy, 8–10 min per batch. Reserve 3–4 tbsp fat; discard rest. Transfer bacon to paper-towel-lined plate.
Cook the Onions
- Cook diced onions in reserved fat over medium heat until soft and translucent with golden edges, 10–15 min. Add garlic and cook 1 more minute.
Deglaze
- Increase to high heat. Add bourbon; scrape up all browned bits. Bubble hard for 2 full minutes to cook off alcohol.
Slow Cook
- Transfer onion mixture and bacon to slow cooker. Add coffee, both vinegars, maple syrup, brown sugar, pepper flakes, black pepper, and thyme bundle. Stir to combine. Cook HIGH 4 hrs or LOW 6–8 hrs. Remove lid for last hour.
Skillet Finish
- Discard thyme. Transfer to a wide 12-inch skillet over medium-high heat. Cook, stirring constantly, 20–30 min until sticky, glossy, and mahogany-dark. Drag test: spoon through jam should hold 1 second before flowing back.
Finish and Jar
- Optional: pulse 2–3 times in food processor for smoother texture. Don't over process, this should have texture.
- Cool completely before jarring.
Notes
- Do NOT put raw bacon directly in the slow cooker — results in greasy, flabby texture that won’t render.
- The skillet finish is mandatory. Slow cooker = flavor. Stovetop = texture.
- Fridge: 2–3 weeks airtight. Freezer: up to 3 months. Always serve warm or room temp.
- Too firm after refrigerating? Stir in a splash of water or bourbon while reheating over low heat.
Nutrition
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Quick Summary
Onion bacon jam is a slow cooker recipe with a mandatory skillet finish. Render the bacon first, caramelize the onions in the fat, deglaze with bourbon, slow cook 4–6 hours, then transfer to a wide skillet and reduce for 20–30 minutes until the drag test holds. Makes 2.5 to 3 cups and keeps 2–3 weeks in the fridge. Find more in our Sauces, Mops & Condiments library.
❓ FAQs
Yes. After deglazing with bourbon, return the bacon to the pan with all remaining ingredients, bring to a simmer over low heat, and cook uncovered for 2–3 hours, stirring every 20–30 minutes. Then do the same skillet finish. The slow cooker just makes the hands-off portion easier.
Two likely causes: the skillet finish didn’t go long enough (more reduction means more bitterness and complexity to balance the sugar), or the coffee was skipped or too weak. Return the jam to the skillet with a splash of balsamic and cook down further. Five more minutes usually fixes it.
The drag test: pull a wooden spoon through the jam and the line should hold for a full second before the mixture flows back together. If it flows immediately, keep cooking. If it holds for 3+ seconds without moving, you’ve gone slightly too far — add a small splash of water and stir over low heat to loosen.
2–3 weeks in the fridge in an airtight glass jar, or up to 3 months in the freezer. Always serve warm or at room temperature — cold bacon fat straight from the fridge has a waxy texture that doesn’t represent the jam well.
