In a large pot (at least 6-quart capacity), combine the 10 cups of water and beer, then bring to a rolling boil over high heat. Add the Zatarain's seasoning, 5 tbsp hot sauce, quartered onion, halved lemon, garlic head (with top sliced off), bay leaves, and fresh thyme sprigs. Stir well to dissolve the seasoning completely. This aromatic base is the foundation of the dish—the beer adds depth while the citrus and aromatics infuse the cooking liquid with complex flavors. Once everything is combined, reduce the heat to medium-high and simmer covered for 10 minutes to allow the flavors to meld together.
Add the small red potatoes to the simmering broth and maintain a gentle boil. After 10 minutes, when the potatoes are just becoming tender, add the smoked sausage coins. The potatoes need about 20 minutes total cooking time to be fork-tender without falling apart. I like to use small red potatoes because they cook quickly and absorb the seasoned broth beautifully without needing to be cut.
After the sausage has cooked for about 10 minutes, add the corn rounds to the pot. Continue simmering for 10 more minutes, until the corn is tender and bright yellow. At this point, all the heartier vegetables and proteins are nearly done, and you're ready for the final addition.
Add the shell-on large shrimp directly to the boiling broth and cook for 4-5 minutes, stirring occasionally, until they turn bright pink and opaque throughout. Don't overcook—shrimp continue to cook from residual heat even after you remove them. I find that leaving the shells on keeps the shrimp incredibly tender and flavorful while also making them easier to eat with your hands at the table.
Using a colander or slotted spoon, carefully drain all the solids from the broth, reserving the cooked shrimp, vegetables, and sausage in a large serving bowl or on a platter. While the broth drains, melt the unsalted butter in a small saucepan over medium heat (about 1-2 minutes). Add the 1.5 tbsp hot sauce and 1.5 tsp Old Bay or Zatarain's seafood seasoning to the melted butter, stirring constantly for another 1-2 minutes until the seasonings are fully incorporated and the sauce is fragrant.
Pour the hot seasoned butter sauce over the drained shrimp, vegetables, and sausage, tossing gently to coat everything evenly. Serve immediately while hot, ideally family-style with crusty bread for soaking up the butter sauce. The rich, spiced butter transforms the boil into a luxurious final dish that guests can customize by dipping each piece as they eat.