Steaming Crabs: Season the Water or the Crabs?
I use half White House apple cider vinegar and half Natty Boh as my steaming liquid. Plunge the crabs in ice water as mentioned so they won't drop claws as a defense mechanism. Add them by layer to your steamer insert and sprinkle with seasoning. I use JO #2 which adheres in a nice, thick layer on the crabs. Repeat until you fill up your pot.
Some of the seasoning is going to fall through the holes in the steamer into the liquid as it cooks. It is probably unnecessary to season the liquid directly.
I don't use Old Bay, maybe just a tiny bit, because I feel its overpowering, especially for blue crabs, which have a good flavor on their own. I just add some salt, peppercorns, mustard seed, coriander, and hot pepper.....and I also use beer. For Dungeness crabs, which are a bit blander, I'll add more seasoning and salt. But I always add it to the water.
Here's how my Dad does it
Put the crabs into Ice water for a few minuets, This sedates them and helps to keep them from dropping claws.
In the water for the steaming put in vinegar we use cider but I think any kind will do. It gets rid of the muddy flavor.
Now put your stunned crabs in the basket and layer with seasoning. We like a mix of Wye River Black and Red.
Steam for 20-30 min depending on size.
This sounds very similar to my method. I have been doing this for years. I use 1/2 white vinegar (cider vinegar sounds like a better bet, I plan to give it a try) and 1/2 beer, no water. The crabs are steamed, not boiled. Put in a layer of crabs, dust w/ Old Bay, another layer of crabs, dust w/ Old Bay, and so on.
20-30 min's sounds about right. Enjoy!!
I live on the coast and have steamed many, many bushels of blue crabs in my lifetime. Have always flavored the "steaming" water with beer. It does make a difference over just using plain water. And when layering the crabs in the pot....each layer gets a generous amount of Old Bay, placed directly on the crabs. This is the only way I seen it done by others too. You don't want to boil them. Steaming is the only way to go!!!