It is bright green. It looks like something you’d find at the bottom of a stagnant pond or perhaps a spill in a chemistry lab. If you didn't grow up in the East End of London, your first instinct upon seeing pie and mash liquor is probably to run. Or at least ask for gravy. Don't ask for gravy. Honestly, asking for gravy in a traditional London pie shop is a fast track to getting a look that suggests you've just insulted the proprietor's grandmother.
What is this stuff, really?
The name is a total lie. There is zero alcohol in liquor. It’s basically a thin, savory parsley sauce. But calling it "parsley sauce" feels like calling a Ferrari "a car." It doesn't capture the history or the specific, salty, slightly earthy punch it delivers when poured over a minced beef pie and a scoop of cratered mashed potatoes.
Historically, this sauce was the byproduct of boiling eels. Back in the Victorian era, the Thames was teeming with European eels (Anguilla anguilla). They were cheap. They were plentiful. They were the protein of the poor. When you boil eels, you get a nutrient-rich, gelatinous stock. To make it palatable, cooks added a massive handful of chopped flat-leaf parsley and a bit of flour to thicken it. That’s the "liquor."
Today, most shops use a vegetable or chicken-style stock base because, frankly, fewer people are eating stewed eels these days. But the soul of the dish remains that vibrant green parsley. It’s the contrast that matters. You have the heavy, flaky suet or shortcrust pastry, the dense beef filling, the fluffy mash, and then this sharp, herbaceous liquid that cuts right through the fat. It's a balance of textures that has kept places like M.Manze and F. Cooke in business for over a hundred years.
The Vinegar Debate and the "London Way"
If you think the green sauce is the end of the flavor profile, you're mistaken. You need the vinegar. Specifically, chili vinegar. Walk into any reputable shop—say, Kelly’s in Roman Road—and you’ll see glass bottles filled with clear vinegar and small, wicked-looking bird's eye chilies.
You don't just drizzle it. You douse.
The acidity of the vinegar reacts with the pie and mash liquor in a way that’s hard to describe if you haven't had it. It brightens everything. It makes the parsley pop. Some people go even further and add a massive dollop of white pepper. It’s a very specific, very London palette. It’s salt, acid, and earth.
Short sentences work best here: It’s simple. It’s cheap. It’s iconic.
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But there's a complexity in the simplicity. The mash isn't supposed to be "Robuchon-style" with 50% butter. No. It should be stiff. It needs to hold its shape so it can act as a dam for the liquor. If the mash is too runny, the whole plate turns into a swamp. You want a structured meal, not a soup.
A History Born of Necessity
London’s East End was a tough place in the 1800s. People needed calories that didn't cost a week's wages. The pie was the original street food. Long before the burger or the kebab, the pie man was the king of the corner. Originally, these pies were filled with eels because beef was expensive.
As the 19th century progressed and the railways brought cheaper meat into the city, the fillings shifted to minced beef. But the liquor stayed. Why? Because the people loved it. It had become part of the cultural DNA. Even as the Thames grew too polluted to fish for eels comfortably, and the "eel, pie, and mash houses" started sourcing their fish from the fens or further afield, the green sauce remained the literal glue holding the meal together.
Why it’s actually healthy (sort of)
Parsley is a powerhouse. We often treat it as a garnish, something to be brushed off a plate, but in pie and mash liquor, it’s the star. It is loaded with Vitamin K, Vitamin C, and antioxidants. In a diet that was historically quite beige—bread, potatoes, suet—the liquor was often the only source of fresh greens for many Londoners.
It’s an accidental health food hidden inside a comfort food.
Of course, the "health" aspect is somewhat negated by the suet pastry, but let's focus on the wins. Parsley is also a natural palate cleanser and breath freshener. Given that traditional pie shops often served jellied eels on the side, a bit of parsley-induced freshness was probably a godsend for anyone planning a social engagement after lunch.
The Modern Survival of the Pie House
The gentrification of London has been brutal for traditional shops. Many have closed. But the ones that remain, like L. Castleton’s or Goddard’s at Greenwich, are thriving because they represent something authentic in a world of "concept" restaurants.
You can’t "disrupt" pie and mash.
If you try to make a "deconstructed" version with a parsley foam, you will fail. The beauty lies in the consistency. The liquor should be the same today as it was in 1920. It should be served on a white marble tabletop. You should hear the clatter of stainless steel cutlery.
Interestingly, there’s a massive regional divide. People from North or South London will argue for hours about which shop is better. It’s like football. You’re born into a pie shop. You don’t choose it. Your dad took you there, his dad took him, and the liquor is the green thread connecting the generations.
How to make it at home without ruining it
If you can't get to Bermondsey or Peckham, you can make it yourself, but don't get fancy.
- Use a good fish or vegetable stock. If you’re feeling brave, simmer some eel bones.
- Make a simple roux with flour and butter (or margarine for that authentic "working class" vibe).
- Slowly whisk in the stock until you have a thin gravy.
- Add way more flat-leaf parsley than you think is reasonable. It needs to be finely chopped.
- Season with plenty of salt.
The most common mistake? Making it too thick. It’s not a béchamel. It’s a liquor. It should run across the plate and soak into the bottom of the pie crust. It should be liquid enough to be sipped from the edge of the plate if no one is looking.
Why the "Eel" Factor Still Matters
Even if you don't order a side of jellied eels, the presence of the eel in the history of the liquor is vital. It’s what gives the dish its "umami" foundation. In the old days, the liquor was seasoned with the liquor from the stewed eels (hence the name).
Today, some shops still add a splash of the eel water to their parsley sauce to give it that depth. It’s a funkiness. A sea-saltiness. It’s the difference between a bland sauce and one that makes your mouth water.
There’s a common misconception that the green comes from food coloring. While some low-quality shops might use a drop of "green" to keep things consistent, a true pie and mash liquor gets its color solely from the sheer volume of chlorophyll in the parsley. If it looks neon, be suspicious. If it looks like a forest after a rainstorm, you’re in the right place.
The Actionable Insight for Your First Visit
If you’re a newcomer to the world of London's favorite green sauce, here is how you handle it like a pro.
First, look at the menu. It will usually say "one and one" (one pie, one mash) or "two and one." Start with one and one.
When they ask if you want liquor, say yes. If you say no, the pie will be dry, the mash will be sad, and the ghosts of Victorian London will haunt your dreams.
Once the plate is in front of you, use the bottom of your fork to mash the pie slightly. You want to create channels for the liquor to flow into. Then, reach for the chili vinegar. Give it three good shakes. Sprinkle some white pepper.
Eat it with a spoon and a fork. That’s the traditional way. The spoon is for the liquor. Every bite should be a combination of the crisp pastry, the soft meat, the salty mash, and a big gulp of that green gold.
Don't overthink it. It's just a pie. But it's also a piece of history that you can eat for about six pounds. In a city where a coffee can cost five, that is a miracle.
Next Steps for the Pie Curious
- Visit an OG Shop: Head to M.Manze on Tower Bridge Road. It’s the oldest in the world (established 1902) and is a Grade II listed building. The liquor there is the gold standard.
- Check the Label: If you’re buying "ready-made" liquor in a supermarket (like Arments or Robinsons), check that parsley is one of the top ingredients, not just flavorings.
- The Vinegar Secret: If you’re making it at home, don't use malt vinegar. You need clear, distilled spirit vinegar infused with chilies. The malt is too heavy and will muddy the flavor of the parsley.
- Avoid the "Gravy" Trap: If a shop offers gravy as the primary option, it’s probably not a traditional London pie house. It might be a great pie shop, but it’s not this tradition.
The world is changing fast, but the green sauce stays the same. It’s a stubborn, delicious middle finger to the fleeting trends of the modern food world.