The 1921 Slider®
Created in April 2021 to celebrate White Castle's 100th Anniversary, The 1921 Slider® replaces the perforated steam-grilled patty with a thick 2.5 oz solid 100% USDA beef patty seared on a flat-top grill and topped with smoked cheddar, caramelized onions, fresh Roma tomato, iceberg lettuce, and dill pickles.
Portion: 1 Slider (142 g / 5.01 oz) · Delivery Est: $4.19
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Wheat, Milk, SoyThe 1921 Slider History & 2026 Availability (Continued vs. Discontinued)
Launched in April 2021 to honor White Castle's 100th Anniversary, The 1921 Slider replicates founder Walter Anderson's original 1921 Wichita, Kansas flat-top seared burger. In 2026, it remains continued at select regional Castles, though many high-volume drive-thru locations discontinued the 2.5 oz patty due to 4-minute grill cook times.
Why It Has No 5 Steam Holes
When Billy Ingram and cook Walter Anderson opened the first White Castle in Wichita, Kansas in 1921, patties were hand-pressed spheres seared directly on a cast-iron griddle with caramelized onions. The 5-hole perforated steam grill was not invented until 1949; The 1921 Slider revives that pre-1949 seared pub crust.
Why Some Locations Discontinued It
A standard Original Slider steams in 90 seconds in batches of 30. Because the 2.5 oz solid 1921 patty requires 3.5 to 4 minutes of dedicated flat-top searing, many 24-hour drive-thru locations removed it between 2024 and 2026, keeping it only at select dine-in and Midwest heritage stores.
How to Order the 1921 Build Anywhere
If your local Castle discontinued the 2.5 oz patty, order a Double Cheese Slider (or Double Bacon Cheese Slider) with Smoked Cheddar and add Roma tomato, iceberg lettuce, pickles, and extra grilled onions. Every Castle stocks these exact ingredients daily.
The 1921 Slider Nutrition Facts & Dietary Macros
Because its 2.5-ounce seared patty is nearly triple the weight of a standard 0.88-ounce slider patty, a single 1921 Slider provides the macronutrient density of a full quarter-pound burger (40% Daily Value of protein and 35% DV of fat).
Protein-to-Calorie Efficiency Breakdown
The 1921 Slider delivers 4.55 grams of protein per 100 calories (4.69g per 100 kcal on the 1921 Bacon Cheese build). Because it uses no mayonnaise or sugary burger sauces, 87% of its carbohydrate load comes strictly from the enriched square wheat bun.
You can combine The 1921 Slider with low-sodium sides or beverage swaps inside our interactive nutrition calculator to plan your exact daily macro targets.
Sodium & Saturated Fat Modifications
Ordering The 1921 Slider without Smoked Cheddar cheese reduces calories by 70 kcal, cuts saturated fat from 10g down to 6g, and lowers sodium from 820mg to 590mg while retaining 16 grams of complete beef protein.
Allergens, Ingredients & Griddle Cross-Contact
The White Castle 1921 Slider contains three declared FDA allergens: Wheat, Milk, and Soy. Unlike deluxe chicken sliders, it contains zero egg or mayonnaise, and it is completely free of peanuts, tree nuts, fish, shellfish, and sesame.
Wheat, Milk & Soy
- • Wheat: Enriched bleached wheat flour & malted barley in the toasted square bun.
- • Milk: Pasteurized Smoked Cheddar slice and dairy whey in the bun glaze.
- • Soy: Soybean oil griddle release agent and soy lecithin in the cheese slice.
No Egg, Nuts, Fish or Sesame
- • Egg-Free: Seasoned with caramelized onions, tomato, lettuce, and pickles—no mayo.
- • Beef Pureness: 2.5 oz patty is 100% USDA beef seasoned only with salt and black pepper.
- • Dairy-Free Swap: Order bunless without Smoked Cheddar for a Milk-free and Wheat-free bowl.
Shared Flat-Top Griddle Alert
The 1921 patty and caramelized onions are seared on a flat-top grill that also toasts wheat buns and melts American, Jalapeño, and Smoked Cheddar cheeses, detailed in official White Castle allergen disclosures.
The 1921 Slider Prices & Combo Bundle Savings
At participating White Castle locations in 2026, ordering the 2-slider 1921 Combo Meal ($10.49) saves $0.87 compared to purchasing two 1921 Sliders, small crinkle-cut fries, and a medium fountain drink individually.
| Menu Option | Portion Specification | In-Store Price | Delivery App Est. | Bundle Value & Savings |
|---|---|---|---|---|
| 1 The 1921 Slider® (Classic Cheddar) | 1 Seared Slider (142g) | $3.49 | $4.15 – $4.35 | Standard à la carte heritage burger |
| 1 1921 Bacon Cheese Slider® | 1 Seared Slider + 2 Bacon Strips (155g) | $3.69 | $4.40 – $4.65 | +$0.20 upgrade for hickory-smoked bacon |
| 1921 Slider Combo (2 Sliders + Sides) | 2 Sliders + Small Fries + 21 oz Drink | $10.49 | $12.69 – $13.29 | Saves $0.87 vs buying items separately |
| 10-Sack of 1921 Sliders (Participating Stores) | 10 Seared Heritage Sliders | $32.99 | $38.99 – $40.99 | Saves $1.91 ($3.30 per slider) |
The 1921 Slider Frequently Asked Questions
Is The 1921 Slider discontinued or still continued at White Castle in 2026? ▼
Yes, The 1921 Slider remains continued at select participating dine-in and regional White Castle restaurants in 2026, though it has been discontinued at many high-volume drive-thru locations. Because the 2.5-ounce solid beef patty requires 3.5 to 4 minutes of flat-top searing (compared to 90 seconds for steam-grilled sliders), several markets phased it off the board to speed up drive-thru service.
Why doesn't The 1921 Slider have the 5 signature steam holes? ▼
The 1921 Slider omits the 5 steam holes because it tributes the original 1921 Wichita, Kansas cooking method developed before White Castle invented the perforated steam-grill system in the 1940s. Instead of steaming over rehydrated onions, the thicker 2.5 oz patty is pressed and seared directly onto a high-heat griddle to form a caramelized Maillard crust.
How can you order a 1921 Slider clone if your local White Castle discontinued it? ▼
If your local White Castle no longer carries the 2.5 oz 1921 patty, order a Double Cheese Slider (or Double Bacon Cheese Slider) with Smoked Cheddar cheese and ask the crew to add fresh Roma tomato, iceberg lettuce, pickles, and extra caramelized onions. Two stacked 0.88 oz patties provide 1.76 oz of beef with the exact same heritage toppings and flavor profile.
Does The 1921 Slider contain egg, mayonnaise, or sesame allergens? ▼
No, The 1921 Slider is formulated without egg, mayonnaise, or sesame seeds. Its only FDA Big-9 declared allergens are Wheat (toasted square bun), Milk (Smoked Cheddar cheese), and Soy (bakery bun conditioner and griddle oil).
Can you order The 1921 Slider without a bun for a low-carb or keto diet? ▼
Yes, participating White Castle locations prepare The 1921 Slider bunless inside a side bowl or iceberg lettuce wrap at no extra charge. Ordering it bunless removes 24 grams of refined carbohydrates from the wheat bun, leaving 5 grams of net carbs from the caramelized onions and tomato.
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