Sous Vide Corned Beef Flat – Amazing 48-Hour Recipe for Tender Results

Growing up in Florida, my family always made corned beef around St. Patrick’s Day. I loved the briny aroma, but honestly? It was hit or miss. Sometimes dry. Sometimes chewy. Fast forward a few years—and one immersion circulator later—and I found myself standing in the kitchen after slicing into my first-ever sous vide corned beef flat. It was pink, juicy, and so tender it practically melted. I knew I’d never go back.

There’s something comforting about cooking a brisket flat low and slow, knowing you won’t ruin it. That’s the magic of sous vide: it gives you total control over texture and flavor. With a simple spice packet and time, this cut transforms into the kind of meal people request again and again.

And trust me, I’ve had my fair share of kitchen fails before sous vide. That’s why I’m sharing this easy approach—so you can get restaurant-quality results without stress. This isn’t just a holiday dish. It’s a meal prep powerhouse, a cozy Sunday dinner, or a sandwich superstar.

If you’re wondering how long to sous vide corned beef, what temp gives that perfect tenderness, or whether you can cook brisket flat sous vide for 24 hours, you’re in the right place. And if you want to try it in a cabbage-style feast later, check out my corned beef and cabbage recipe for more.

Let’s dig into the technique that changed my view of brisket forever.

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How Sous Vide Transforms Corned Beef Flat

Why brisket flat loves sous vide

Corned beef is typically made from the brisket flat—leaner than the point, but full of potential when treated right. The problem? Traditional methods like boiling or oven roasting can dry it out. Enter sous vide. By cooking it at a precise, low temperature (we’re talking 140°F for 48 hours), the collagen has time to break down slowly, making it tender without losing moisture.

Compare this to the boil-and-hope approach, and it’s not even close. You get even texture, no stringy bits, and all the flavor stays locked inside.

And because corned beef comes pre-cured with pickling spices, you’re already halfway to delicious. Just rinse the excess brine, season with the included spice packet, and seal it up. No guesswork.

Understanding how collagen breaks down over time is what makes sous vide brisket so different from boiled or braised versions. For a deeper dive into sous vide brisket texture and timing, this guide by Serious Eats is gold.

For variations or if you’re curious whether you can sous vide corned beef in the original packaging, I’ve got a full breakdown right here.

Sous vide vs. other cooking methods for brisket

Let’s break it down:

Method	Cook Time	Texture	Juiciness
Boiled	3–4 hours	Can be stringy	Medium
Roasted	2.5–3 hours	Dry edges possible	Low–Medium
Sous Vide	48 hours	Uniformly tender	High

Once you try sous vide for corned beef flat, it’s hard to go back. Plus, if you’re interested in experimenting with other beef cuts, the tri-tip steak sous vide guide and flat iron steak recipe are worth exploring next.

Timing & Temperature for Perfect Results

How long do you Sous Vide Corned Beef Flat?

When it comes to Sous Vide Corned Beef Flat, time matters more than you might think. Because it’s a tougher cut loaded with connective tissue, you need time to transform it. The sweet spot? 48 hours at 140°F (60°C). This gives you a sliceable, tender brisket with just the right chew.

But can you cook it faster? Sure—but results vary.

• 24 hours at 140°F: Still good, but firmer, with less collagen breakdown.
• 36 hours: Better, but still not as juicy as the full 48.
• 48 hours: Ideal. Full tenderness without mushiness.

If you’re ever tempted to push it past that (like 72 hours), just know you’ll start to get a looser, almost shredded texture. Still tasty, but not classic sliced brisket flat.

Some folks go hotter for a more traditional braise-like feel. At 170°F for 10–12 hours, you’ll get fall-apart meat—but that’s a different texture entirely. For a guide on how different Sous Vide Corned Beef Flat temps stack up, check out this prime rib temp chart. Want to know how collagen transforms at different temps? AmazingRibs.com explains it in detail. https://amazingribs.com/tested-recipes/beef-and-bison-recipes/texas-brisket-recipe

What temperature should Sous Vide Corned Beef Flat be cooked?

Here’s where sous vide shines: you control the doneness, not just whether it’s safe to eat. Traditional methods often blast brisket until it’s just “done” and forget texture.

For corned beef flat, these are your best temperature zones:

Temperature	Time	Texture
135°F (57°C)	48 hours	Very tender, slightly firm
140°F (60°C)	48 hours	Perfect balance, sliceable
165°F (74°C)	10 hours	Shreddable, pot roast texture

What about silverside? This leaner cousin of brisket is common in the UK and Ireland. Treat it just like corned beef flat: 135–140°F for 48 hours works great. Learn more about timing for leaner cuts in my ground beef sous vide timing guide. Looking for a shortcut? A 24-hour sous vide brisket can work, but expect more chew. For pulled texture, that’s fine. But for tender slices? Go 48.

Higher-temp cooks like 165°F turn collagen into gelatin faster, but at the cost of texture precision. You can explore the brisket collagen breakdown science if you’re experimenting with a more shredded style.

Step-by-Step Guide to Sous Vide Corned Beef Flat

Prepping and bagging Sous Vide Corned Beef Flat

Start with a 3-pound corned beef brisket flat—ideally one that comes with a spice packet. Most store-bought corned beef is already brined, so the first step is crucial: rinse it under cold water to remove excess salt and surface brine. Pat it completely dry with paper towels.

Now, grab that spice packet. Some folks toss it, but I recommend using it—it brings in the signature pickling spice aroma. Sprinkle the seasoning generously over the fatty side of the brisket and press it in.

Next, bag it. You’ve got two options:

• Vacuum seal: Best for long cooks (like this 48-hour one). Just make sure the seal is tight and clean.
• Water displacement: If you’re using a zip-top freezer bag, lower it slowly into the water bath until the air is pushed out, then seal.

Want a visual? Check out the prep photos in this amazing sous vide corned beef guide for a perfect bagging technique.

Pro tip: Don’t skip the seal check. Leaks after 36 hours are heartbreaking.

Cooking, resting, and slicing like a chef

Place your sealed bag of Sous Vide Corned Beef Flat into a preheated 140°F (60°C) water bath. Clip it to the side or use a rack to keep it submerged. Set a timer for 48 hours. Yes, it’s long—but the results are worth it.

After the time’s up, pull the bag out and transfer the beef to a cutting board. You can slice and serve immediately—but resting it for 10–15 minutes will make slicing even easier.

Now the crucial part: slice against the grain. Sous Vide Corned Beef Flat has long muscle fibers, so slicing crosswise shortens them, giving you that perfect tenderness.

Want a crust? Pat the meat dry and torch it, or pan-sear briefly. I usually skip this since corned beef is all about the soft bite, but it’s an option if you’re looking for visual contrast.

Serve with cabbage, potatoes, or tuck into a sandwich. For a full meal idea, try this corned beef and cabbage recipe—just swap in your perfectly cooked brisket flat.

And if you’re up for experimenting beyond brisket, try something like dishwasher sous vide steak—yes, seriously.

Beyond the Basics: Variations, Storage & Tips

How to flavor it your way – Sous Vide Corned Beef Flat

The beauty of sous vide is how well the meat absorbs flavor over time. While the spice packet adds a classic touch, you can customize it with little effort. Try one of these add-ins inside the vacuum bag:

• Garlic and bay leaf: Add a mellow earthy note.
• Crushed mustard seeds and coriander: Boost the pickling vibe.
• A tablespoon of brown sugar: Balances out the salt with a sweet-savory kick.
• A splash of Guinness or beef broth: Adds depth and pairs beautifully with cabbage sides.

If you’re feeling bold, coat the brisket in Dijon mustard before cooking—like a DIY pastrami base. (Finish with a crust of black pepper and coriander after the sous vide stage.)

For a next-level version that finishes in the smoker, see my amazing ribs-style prime rib recipe—you can adapt it for brisket flat, too.

Storage, meal prep, and reheating of Sous Vide Corned Beef Flat

Here’s where sous vide really shines: make it once, enjoy it all week.

To store:

• Keep in the vacuum bag, chill in an ice bath for 30 minutes, then refrigerate (good for 6–7 days).
• For longer storage, freeze the bag for up to 3 months.

To reheat:

• Drop the sealed bag back into a 135°F water bath for 1–1.5 hours.
• Or slice and gently reheat in a pan with a splash of broth.

Slice it thick for dinner, thin for sandwiches, or dice it for hash. Toss extras into a skillet with potatoes and eggs and you’ve got a brunch people will talk about.

Also, if you’re curious about what else you can meal-prep with sous vide, check out this flat iron steak recipe or my go-to tri-tip guide—they reheat beautifully, too.

Sous vide corned beef flat isn’t just for holidays—it’s a year-round staple that fits almost any meal.

Conclusion

There’s something deeply satisfying about slicing into a perfectly tender sous vide corned beef flat. No guesswork. No overcooked edges. Just consistent, juicy results every single time. Whether it’s for St. Patrick’s Day, Sunday dinner, or the ultimate sandwich, this method delivers a bold payoff with minimal effort.

Sous vide transforms a humble brisket flat into a melt-in-your-mouth centerpiece. And once you’ve tasted the difference, there’s no going back. From choosing the right temperature to finishing with the perfect slice, you now have everything you need to make this dish confidently at home.

If you’re ready to explore even more beef recipes, check out my best sous vide corned beef guide or try the juicy tri-tip steak sous vide method next.

Happy cooking—and don’t forget to slice across the grain.

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Frequently Asked Questions

How long do you sous vide corned beef flat?
The ideal time is 48 hours at 140°F (60°C). This gives the meat enough time to break down collagen, resulting in a tender and juicy texture. Shorter cooks (24 or 36 hours) are possible, but not as tender.

How long to sous vide a brisket flat?
For brisket flat specifically, 48 hours at 135–140°F offers the best balance between sliceable and tender. If you prefer shreddable texture, go 10–12 hours at 165–170°F instead.

What temperature is sous vide corned beef flat done?
Corned beef flat is safe to eat above 130°F, but optimal texture is reached at 140°F over a long cook (48 hours). This ensures it’s fully pasteurized and perfectly tender.

What temperature is sous vide Silverside?
Silverside responds well to 135–140°F for 48 hours in sous vide. It’s similar to brisket flat in texture and leanness, and benefits from the same slow approach.

What temperature do you sous vide beef at?
That depends on the cut. Tough cuts like brisket do best between 130–170°F over long times. Tender cuts like ribeye or filet are great at 129–134°F for 1–4 hours.

At what temperature should Sous Vide Corned Beef Flat be cooked?
Sous vide style: 135–140°F for 48 hours. Traditional boiling methods usually go much higher (180°F+), but lose more moisture.

Can you sous vide brisket in 24 hours?
Yes, but expect firmer results. For best tenderness, go 36–48 hours. If you’re in a rush, a 24-hour cook at 145°F can still yield solid flavor—just not as soft.