Think Twice Before Pouring That Bacon Grease: Real Talk from a Plumber
Hi, I’m Dennis, the owner of Veteran Plumbing Services in Falls Church, VA.
I’ve been unclogging drains for decades, and let me tell you – one of the most common culprits is cooking grease buildup.
Pouring leftover bacon grease, frying oil, or other fats down the kitchen sink is a recipe for clogs.
In fact, the EPA found that grease from kitchens is the number one cause of sewer blockages, responsible for about 47% of reported sewer system blockages.
Plumbers and environmental folks even have a nickname for this problem: FOG, which stands for fats, oils, and grease.
FOG comes from everyday foods like cooking oil, lard, butter, meat drippings, and creamy sauces, and it might be liquid when hot – but it quickly cools and hardens like wax inside your pipes.
The result? A gunky clog that can stop up your drains and even cause sewage backups into your home if it gets bad enough. Not fun!
Now, I want to explain which kitchen greases and scraps are most likely to clog your drains, how these sticky substances build up (ever heard of a **“fatberg”? 🤢 I’ll explain!), and the common mistakes I see homeowners make – like rinsing pans with hot water or relying on the garbage disposal (spoiler: those tricks don’t work).
I’ll also share safe disposal methods for grease, including some handy programs we have here in Fairfax County for recycling cooking oil. Finally, I’ll wrap up with why I strongly recommend annual plumbing inspections to check for grease build-up.
A little proactive maintenance can save you a ton of money and prevent nasty plumbing emergencies down the road. Let’s dive in (not literally, I hope!) and talk about fighting the grease menace in your pipes.
The Usual Suspects: Grease and Food That Clog Drains
When it comes to clogged kitchen drains, not all foods are equal – some are repeat offenders. Over the years, I’ve learned to blame certain greasy foods first whenever a client’s sink is slow or blocked. Here are the worst culprits (the “usual suspects”) that I see turning into gooey globs in people’s pipes:
- Bacon grease and lard: After cooking bacon or frying something in lard, you’re left with liquid fat that solidifies into a thick blob at room temperature. This stuff hardens like candle wax in the drain and is excellent at causing clogs.
- Butter, shortening, and coconut oil: These fats might start as a warm liquid in your pan, but they cool into solids. A pat of melted butter poured down the sink can re-harden inside the pipe a few feet down. Coconut oil is especially sneaky – it’s often liquid when warm, but turns solid below about 76°F, coating pipes with an oily white wax.
- Vegetable oils (like canola, olive, etc.): You might think, “Oh, it’s just liquid oil, it will flow through.” Unfortunately, even liquid cooking oils don’t stay harmless. They float on water and stick to pipe walls, catching food particles and gradually building up a slick coating inside the drain. Over time, that coating thickens into an obstruction.
- Greasy sauces and gravies: That delicious gravy or creamy sauce is full of fat. When you rinse it down the sink, the fatty portions will congeal. I’ve pulled out drains clogged with what looked like petrified Alfredo sauce. Soups and stews with oil or grease (like that layer of fat on top of cooled soup) do the same thing.
- Meat scraps and drippings: Little bits of meat or poultry skin, and the fatty juices from cooking them, can accumulate as well. Meat fats (think Thanksgiving turkey drippings, sausage grease, etc.) are a big part of FOG clogs. Even if you have a garbage disposal, those greasy meat scraps don’t magically vanish – they get shredded and then stick to any grease already in the pipe, making the build-up worse.
All of these contain fats or oils that don’t stay liquid for long.
Once they’re in your cool pipes, they cling to the pipe walls and solidify into stubborn layers. It’s a lot like cholesterol in your arteries – grease narrows the “flow” inside your pipes until water can barely get through.
And if you keep adding a bit of grease here, a bit of oil there, the layer keeps growing.
How Grease Builds Up (and Turns Into “Fatbergs”)
So, what actually happens after you pour that frying oil or drop those greasy leftovers down the drain? Initially, it might seem like it “went away” – the hot liquid flows through the trap and into your plumbing.
But hidden from sight, the cooling process begins. As the fats and oils cool, they turn viscous, then eventually solidify on the inner walls of your pipes. The next time you drain something else (even plain water), the flow pushes the grease a bit further along and cools it even more, layering it on like coats of paint inside the pipe.
Over days and weeks, that thin greasy film builds up into a thick sludge. It often starts in the kitchen drain line and can extend into the larger sewer line.
Think of it like a snowball effect: a little grease catches some food bits, which catch more grease and more bits. In technical terms, that’s a FOG deposit. In plumber terms, it’s a nasty blob that’s clogging your pipe.
If this keeps happening unchecked, the grease blob can grow big enough to significantly reduce the flow diameter of the pipe – I’ve seen pipes where the opening was choked down to the size of a pencil. Your once 2-inch-wide drain line can get a scary slim opening due to all that hardened fat.
If this sounds gross, well, it is! These accumulations of grease can grow into what we call “fatbergs.” A fatberg is basically a rock-like mass of fat, oil, grease, and whatever else gets caught in it (food scraps, wet wipes, hair – you name it).
Over time, small clogs from multiple homes can merge in the public sewer and form a huge fatberg down the line. Cities around the world have found colossal fatbergs in their sewer systems – we’re talking masses weighing hundreds of pounds (or even several tons) of solidified gunk. Even in your home’s plumbing, the same process of FOG accumulation is happening on a smaller scale.
The greasy lump in your kitchen drain might not make the news like London’s 130-ton fatberg, but it can certainly cause a nasty backup into your sink or dishwasher. And if that greasy blockage occurs in your main sewer line, it could even cause sewage to back up into your basement or bathrooms (yikes!).
Besides causing blockages and overflows, grease build-up can also damage your pipes over the long term. As FOG sits in the pipe and breaks down, it can create fatty acids – basically an acidic goo that corrodes metal pipes and even eats into concrete.
That’s right, years of grease can actually chew holes in iron pipes.
I’ve seen older cast iron drain lines that were almost swiss-cheesed from a combination of grease and chemical drain cleaners.
The bottom line: hardened grease clogs (“fatbergs”) are bad news all around – they’re hard to remove, they stop your drains from flowing, they can cause sewage spills, and they might even ruin the pipes themselves.
Common Grease Disposal Mistakes (What NOT to Do)
Most of my customers don’t pour bacon fat down the drain thinking it’ll clog – the problem is, a lot of folks have heard some bad advice or myths about how to handle kitchen grease. Let’s clear up a few of the common mistakes I often hear people make when it comes to fats, oils, and grease in the kitchen:
- “I flush it with hot water, so it’s fine.” – This is probably the #1 myth I encounter. Yes, hot water will melt grease temporarily and may push it a little further down the line. But as the water cools, the grease will re-solidify further along in your pipes. You’re basically just moving the clogging material from one spot to another (and possibly into a place where it’s even harder to reach). Eventually that hot water turns cold, and your grease turns back into solid gunk coating the pipe. So no, hot water doesn’t solve the problem – it delays it and often makes it worse by moving it deeper.
- “I use dish soap to break it up.” – I’ve heard people say that chasing the grease with a squirt of dish soap will emulsify it and carry it away. While soap can break up grease in the moment, once that soapy water goes down the drain, it dilutes, loses its effectiveness, and the grease can re-coalesce on the pipe walls. The slick soapy mixture may travel a bit further, but eventually the soap gets rinsed off and you still have fatty deposits in the line. In short, you can’t just magically “dissolve” oil and fat with a bit of soap forever – it’s going to solidify somewhere.
- “It’s okay if I use the garbage disposal.” – Another misconception is that if you have a garbage disposal, it will chew up the grease and food so nothing bad happens. The truth: a garbage disposal does not get rid of grease. It doesn’t have special powers to separate oil from water, and it won’t prevent dissolved fats from solidifying. The disposal will grind up solid bits of food (which you also shouldn’t overload, by the way), but fats and oils will slip right through anyway. In fact, using the disposal for greasy scraps can make things worse by breaking them into smaller particles that then mix with the grease and stick to pipes further down. So don’t trust the disposal to save you from grease – it can’t.
- “Liquid oils are safe to pour – they don’t harden.” – This one is tricky because it feels intuitive: if it’s a liquid (like canola or olive oil) at room temperature, it must stay liquid, right? Wrong. Cooking oils will float on top of water in the pipes and cling to the insides. Over time, that layer of oil catches other particles and can polymerize (thicken). Plus, remember many “liquid” oils (like olive oil) can become pretty thick and gooey in a cool environment (think of olive oil in the fridge – it gets cloudy and sludgy). So even liquid fats can create blockages. The oily film they leave can combine with bits of food and start a clog just as well as bacon grease does.
In a nutshell, no shortcut or gimmick negates the fact that grease and drains don’t mix. Hot water, soap, disposals – none of these prevent the eventual buildup of FOG in your plumbing.
The only surefire way to avoid a grease clog is not to put grease down the drain in the first place.
As one locality here in Virginia puts it, “It’s easy to forget, but eventually the water will cool, and the grease will solidify” – meaning that grease will always harden somewhere.
Keep that in mind next time you’re tempted to dump that oily pan down the sink and “flush it real quick.”
Safe Ways to Dispose of Cooking Grease (Do This Instead!)
Alright, so if we don’t put grease down the sink, what should we do with it? The good news is there are plenty of safe, mess-free ways to dispose of fats, oils, and grease from cooking. As a plumber (and a homeowner who cooks!), here are the methods I personally use and recommend to all my customers:
- Collect grease in containers: Keep an empty heat-safe container (like a coffee can, jam jar, or an old soup can) specifically for grease. When you’re done cooking, pour or scrape the grease into this container instead of down the drain. You can use a funnel or line the can with foil for easy cleanup. Let it cool and solidify in the container. Once it’s full and the grease has hardened, throw the whole container in the trash. Many experts call this the “can it and trash it” method. (Tip: You can store a container of used grease in the freezer to prevent any odors, then toss it on trash day.)
- Scrape food scraps into the trash or compost: Before you even wash a greasy pan or plate, scrape off the leftover food bits into the trash (or compost bin if those scraps are compostable). Use a spatula or paper towel to get as much food and fat off as possible. This goes for plates with gravy, pans with bits of meat, etc. The less that goes down your drain, the better. Wipe down greasy cookware with a paper towel to soak up residual oil before rinsing or washing. That way, you’re putting far less grease into your plumbing.
- Use a sink strainer and (if needed) a grease trap: I always advise using a sink strainer to catch food particles – it’s a simple little basket or mesh that sits in your drain and catches solids. This keeps things like veggie peels, rice, and meat bits out of the pipes (where they could join forces with grease). For most homes, that plus good habits are enough. If you do a ton of cooking with oil (say you fry foods every day or run a home-based catering business), you might even consider installing a small grease trap under your sink. Grease traps/interceptors are more commonly used in restaurants, but they do exist for residential use. They capture FOG before it enters the sewer by slowing down the wastewater flow, allowing the grease to cool and rise to the top for collection. It’s an extra step that can help if normal disposal methods aren’t keeping up with your household’s grease output.
- Take advantage of Fairfax County grease disposal programs: Here in Fairfax County, we’re lucky to have options for disposing of cooking oil properly. Large quantities of used cooking oil (think turkey fryer oil or the jug of oil from your deep-fryer) can be recycled at county facilities instead of tossed out. The county’s Household Hazardous Waste program accepts liquid cooking oils (vegetable, peanut, canola, olive, etc.) every day at the I-66 Transfer Station and the I-95 Landfill Complex for recycling. All you have to do is collect your used fryer oil in a sealed container and drop it off at the facility. They’ll take it for free. Important: They only want liquid oils – fats that solidify (like bacon grease or shortening) should be sealed in a can and put in your regular trash (as we described above). Fairfax County literally says “No Fats, Oils or Grease Down the Drain” – they encourage residents to “can the grease” and use these disposal methods instead of dumping it. By following these programs, you not only protect your own plumbing, but also help prevent sewer clogs in the community. (If you’re outside Fairfax, check your local government or waste management – many areas have similar grease recycling or drop-off options.)
By using the methods above, you’ll significantly reduce the amount of FOG that ever enters your pipes.
It might seem like a bit of extra effort at first, but trust me, it becomes second nature. Instead of dealing with a nasty clog and an emergency plumber visit, you can just throw out a can of solidified grease once in a while.
It’s a small hassle to save yourself a giant headache.
As the saying goes in our industry: Cool it, can it, trash it! – meaning let the grease cool, put it in a container (can), then throw it in the trash. Do this, and your pipes will thank you.
The Importance of Regular Plumbing Check-Ups
Even if you’re very careful about grease, a little bit of FOG can still sneak through into your drains over time – it happens to the best of us. Maybe it’s the residue from washing a buttery dish, or some gravy you couldn’t scrape out completely.
Over the months and years, even tiny amounts can accumulate.
That’s why I recommend annual plumbing inspections, especially if you suspect grease build-up or if you’ve had a history of clogs.
During an annual check-up, a plumber (like yours truly) can do a drain line inspection – often with a camera snake – to see if there are any developing grease coatings or other issues. We look for early signs of narrowing in the pipe.
If we spot a lot of greasy gunk, we can clean it out before it causes a blockage.
It’s much easier (and cheaper) to remove a partial build-up proactively than to emergency-clear a fully clogged pipe after it backs up.
I’ve had customers who were shocked when we showed them the camera footage: “That’s in my pipe?!” – a half-inch thick layer of old grease lining the pipe interior.
But catching it early meant we could hydro-jet or snake the line clean on a scheduled visit, avoiding a nasty overflow in their kitchen later on.
Regular inspections can also check the overall health of your drainage system.
We might find other issues like tree roots starting to intrude or minor clogs forming from other debris.
Think of it like a doctor’s check-up for your home’s plumbing – a quick annual look can prevent a lot of pain down the road.
And if your drains are completely clear, great! You get peace of mind knowing your habits are working and your pipes are in good shape.
From my real-world experience, proactive maintenance is key.
Homeowners who adopt good grease disposal practices and have their drains checked periodically rarely have major clogs.
On the other hand, I’ve done emergency calls where lack of maintenance (and maybe a bit of “pour and ignore” habit in the kitchen) led to a spectacular grease clog that could have been prevented.
So, to wrap up: Keep fats, oils, and grease out of your drains as much as humanly possible.
Use the disposal methods we talked about – collect it, wipe it, trash it, or recycle it – instead of dumping it down the sink.
Educate your family members too, so everyone is on the same page (no secret grease dumping!).
Remember that even a little grease each day can add up to a huge problem, like how cholesterol builds up in arteries.
By being mindful now, you’ll avoid the disgusting fatberg surprises and sewer backups later.
And don’t forget to consider a yearly drain inspection, especially if you suspect any buildup.
It’s a cheap insurance policy against future plumbing disasters.
Stay grease-free and keep those drains clear by scheduling a pipe inspection today!
As a plumber who’s seen it all, trust me – a clean, fat-free pipe is a happy pipe.
Your wallet and your plumbing will thank you in the long run. Happy cooking (and responsible grease disposal)!
Sources: EPA and Fairfax County guidance on FOG (fats, oils, and grease) handling, plus local campaigns reminding folks that grease clings to pipes and causes clogs.
