1.  What is New England Clam Chowder?
There are many types of chowders and stews comprising various types of fish and/or shellfish, vegetables, herbs, meats, and liquids. Here we are talking about clam chowder and to refine that even further, New England Clam Chowder. There are other chowders from the area like Rhode Island Clam Chowder which has a clear broth and Manhattan Clam Chowder which has a tomato broth but we're not going to contrast and compare the merits of those dishes. Having grown up in the Boston area I have learned that New England clam chowder is a very varied and personal dish. Sure, all variations of New England Clam Chowder are white but that's where the similarities pretty much stop.
At home when I was younger my mother would always make fish chowder, never clam chowder. It was that way in her house also. It was made with salt pork, whatever fresh fish was available, fish stock, onions, potatoes and milk, and was never thickened using flour or cornstarch. So my taste tends toward the simpler, thinner chowders. I have no objection to adding a little flour or cornstarch to a chowder as a binder but you really should not be able to tell it's there. So what is chowder and what makes a good chowder? Let's see.
2.  Chose a source of fat
You start with rendered fat from bacon or salt pork. Or I suppose if you are a little more health conscious and want a simpler flavor you could just use vegetable oil. I prefer salt pork which is going somewhat against the grain these days because bacon would probably be more common. But remember the fish chowder I mentioned earlier? My mother always used salt pork that was cut in little cubes and then rendered. And the best part was we got to sprinkle the salt pork cubes into the chowder before eating it. Undoubtedly the best part!
And I am enough of a fanatic that if chowder does have bacon I typically don't like it. I think bacon is too overpowering in this dish, especially if pieces of it are mixed into the chowder. Also, in New England, salt pork was more widely used in things like baked beans and my mother even used it to render fat to fry a nice piece of fresh caught haddock. Now that's good!
3.  Selecting the vegetables
Now the vegetables. Most recipes will have chopped onion which would be sauteed in the rendered fat. I like to add some celery. I think it adds a wonderful flavor to the dish and also adds a little "soft crunch" to the texture. Somewhere in between a potato and a clam. But feel free to omit if you don't like celery. I have also seen recipes with garlic but I just don't get that. Again, I think it's too strong.
4.  Considerations for the broth
Thickeners in chowder is an age old discussion and probably the biggest differentiator between chowders. We need to understand what thickens a chowder and then decide how we want to approach it. Most people think of flour or cornstarch as the primary thickeners, but there are other ways. The other options are the clam juice, the potatoes, and the milk product(s) we choose. Clam broth/juice/stock (hereinafter called broth) is always going to be a liquid that is just slightly thicker than the consistency of water. You can buy it bottled which is certainly a convenient and very acceptable way to do it. Try to get a good brand and you might even want to try a little taste test between brands to find your favorite.
The other way to get it of course is to go out and buy (or dig) some fresh clams (more on what type later) and after cleaning them put them in a pot on a steamer rack with some water or bottled clam broth and cook the clams. See 8 Things to Consider When Steaming Hard Shell Clams in our Techniques section. The resultant broth is heavenly and makes an amazing, though somewhat stronger, chowder base. Now that we have decided what to use, the reason clam broth is so critical to the thickening process is if I add too much it is difficult to thicken the chowder naturally. It will take flour or corn starch. But if we add less to get a thicker chowder we will pay for that in flavor. And that balance is so critical to a nice clean tasting chowder. Just remember, this is clam chowder and a good deal of the clam flavor comes from the clam broth.
5.  Potato options
Potatoes are a great natural thickener. I can adjust the thickness component by the type of potato I use, the size of the dice and the cooking time once they are added. As far as I'm concerned I would only ever use peeled russet potatoes. I think the starch content adds tremendously to this dish where the finished consistency is one of softness and if cooked properly, you know it's there but it doesn't fight you. It has that very inviting texture. So when you bite into a piece of potato and a piece of clam, you would never mistake one for the other and together with the milk base it forms a creaminess where you find yourself just chewing that tender little piece of clam. Regarding the type of potato, I have seen chowders with new potatoes and yukon gold potatoes. They are fine but the starch content is lower and they tend to hold together better and not provide the thickening effect that a russet would. This is a personal thing and it is important to understand the result you are after.
So let's talk about dice size and cooking time and how that affects the end product. A russet potato will dissolve in water if cooked long enough. And if you put enough of them in there the water will get very thick. So if we are adding our potatoes after we add the clam broth and before we add the milk product, we have a lot of options here as to how we want this to affect the thickness of our chowder. For example, I could add a little finely diced or even grated potato into the clam broth, cook it for a bit and then add my diced potato. The result would be that the small dice would dissolve in the broth while the larger dice would be perfectly tender when we were ready to add the milk products. But either way be careful with this, too much potato dissolved in the water can negatively affect the taste and the consistency.
We want an amount that doesn't overpower the milk product but rather complements it to allow the creaminess of the milk products to come through. Think of making mashed potatoes. Normally I would add milk to the potatoes until I thin the potatoes a little bit. But think of it the other way. Suppose I had a cup of milk and added a tablespoon of mashed potato. It wouldn't have much of an effect. But if I keep adding potatoes to the milk, eventually it would be the consistency of mashed potatoes and that's not what we want. The goal should be to move you toward your desired consistency but don't move so far that all you taste is potato.
6.  What type of dairy products
The third option for thickening is the milk product. You have milk, half & half and cream. Milk will give you the lightest and cleanest chowder. Once you start to add cream in the form of half & half or light to heavy cream, you are now changing the flavor profile and the texture of the dish. Think of having a bowl of oatmeal or cold cereal with milk vs. cream. Just remember, too much cream is not always a good thing, even though it will produce a thicker chowder. I have had chowders that were quite apparently made with heavy cream (and sometimes even butter) but I found the whole dish to be lacking in balance. In any event, use good quality dairy products and figure out what you like.
7.  Selecting and preparing the clams
Now that we have our thickening issues resolved, we need to decide what kind of clams to use. Obviously canned clams are the easiest, most readily available and your most consistent option. There are all kinds and brands of canned clams, from chopped to whole baby clams to large clams in a can. So if you go this route experiment and find something you like. But, and this is a big but, to be authentic and true to the origins of clam chowder, you really should be using at least some fresh clams, and to be more particular, hard shell clams. In New England they are distinguished from soft shell clams which are used as "steamers". Those are the ones with the long necks and oblong in shape. Steamers are not a great choice for chowder because of the amount of grit they tend to keep with them. Not a good texture in chowder for sure.
The most common hard shell clams you will find readily available are little necks, cherrystones and quahogs. The difference is in the size of the clam with the little necks being the smallest and quahogs being the largest. There are technically a few other sizes in there but focus on these and you will be fine. Little necks are great but they are smaller so they will require more work. And Quahogs (pronounced Ko-hogs) are known as chowder clams because they are so big that chowder is the primary thing for which they are used. My personal favorite is the cherrystone but experiment and see what you like. And if you use little necks you can eat a few right out of the shell while you are cooking, although be prepared to pay more also.
8.  Additional flavorings
Now your plan has almost come together. Only one more decision and this can have a big impact on the finished product. What else do I add to enhance the flavor? Most people add a little salt and pepper somewhere during the cooking process. I happen to like salt and white pepper added while cooking the chowder and then adding some fresh ground black pepper to the bowl. But be a little careful with the pepper, we're not making gumbo here and we don't want to really taste the pepper.
Some people, including me, will also add a little fresh thyme somewhere during the process. One warning, a little goes a long way and I really don't think you should substitute dried herbs for fresh here, but again, it's all about you. Some people will also add bay leaves, marjoram, hot sauce, Worcestershire sauce, sherry and whatever else is in the pantry. To me, that's the reason you cook. So you can make things the way you like them.
And don't ever let anyone tell you you are not making "real" New England Clam Chowder. If you have the main ingredients we talked about, you are making real chowder. So at the end of the day, make your own plan, develop your recipe and make the best New England Clam Chowder anywhere. Or the next time you sit down in a restaurant and order a bowl of clam chowder think about how it was made and and whether it really is a "good" bowl of chowder.