Homemade vegetable broth, from scraps

October 3, 2010 at 12:46 am (Cook's Illustrated, Georgeanne Brennan, Uncategorized)

I was looking for my notes on vegetable broth and was surprised to discover that I’ve never written about it on my blog.  There are a million blog posts about making vegetable broth, and I’m by no means an expert, but I decided to make a post to keep track of all the broth-related info that I find online.

There are a million vegetable broth recipes out there, but most of them are just recipes.  They never explain why they chose the vegetables and spices that they chose.  The first really detailed analysis I found of what each vegetable contributes (good or bad) was in Cook’s Illustrated.  Unfortunately, I don’t have that print issue and the online entry doesn’t contain the analysis, just the recipe.  If anyone has the September 2000 issue of Cook’s Illustrated, and a little time on your hands, please do send me a summary of which vegetables they tried in their lengthy vegetable stock experimentation, and what they thought of each.

Recently a friend emailed me a vegetable broth recipe from the Anson Mills website.  It was surprisingly similar to the Cook’s Illustrated recipe, calling for (nontraditional) cauliflower, lemongrass, and collard greens.  Did the same person write both recipes?  I searched around a bit and found a recipe on their summer 2009 newsletter that confirmed my hunch. (Sadly the link no longer works.)  Unfortunately neither the newsletter nor the recipe cites the creator’s name.  The author says that the Anson Mills recipe is based on everything she learned in the process of creating recipes for Cook’s Illustrated and the New York Times.  I was curious what changed in the nine years between the two recipes, and so I compared them below.

	2000 recipe (Cook’s Illustrated)	2009 recipe (Anson Mills)
onions	2 med, 12 oz.	2 med yellow
garlic	10-12 cloves from 1 head, peeled and smashed	1 head, unpeeled and halved
shallots	8 large (8 oz), sliced thin	3 large, sliced thin
celery	1 rib, chopped coarse	1 small ribs, chopped
carrot	1 small, peeled and chopped coarse	2 small, peeled and chopped
leeks	4 large, white and light green part only, chopped coarse (about 5.5 cups)	2 large or 4 small, white and light green parts only, halved lengthwise, sliced
bay leaves	2	1
salt	1.5 tsp. table	2 tsp. fine sea
peppercorns	1 tsp., coarsely crushed	2 tsp.
collards greens	1 pound, washed, dried, and sliced crosswise into 2-inch strips (about 10 cups packed)	1 bunch (12 ounces), washed and chopped
cauliflower	1 small head (about 12 ounces), chopped fine (about 4 cups)	1 small (12 ounces), trimmed of stem and leaves, sliced
parsley	stems from 1 bunch	1 bunch flat-leaf, washed, shaken dry and coarsely chopped
thyme	8-10 sprigs	none
lemongrass	1 stalk, trimmed to bottom 6 inches and bruised with back of chef’s knife	1 stalk, trimmed to bottom 6 inches and bruised with back of chef’s knife, or one halved lemon
scallions	4 medium, white and light green parts, cut into 2-inch length	2, washed and trimmed, chopped
rice vinegar	2 tsp.	none
winter squash	none	Half of a small acorn squash or the bulb end of a butternut squash, unpeeled and with seeds, cut crosswise into 5 slices, each about ½ inch thick
water	about 2 quarts (8.5 cups)	3 quarts spring or filtered
makes	about 1 quart	about 2 quarts

1. Both recipes have you start by adding the sweet vegetables (onions, shallots, leeks, garlic, and carrots) and the celery to an 8 quart heavy-bottomed stockpot or dutch oven, and then have you spray the vegetables with oil spray and stir.  The pot is covered and the veggies are cooked over low heat until they are soft, fragrant, and beginning to color, about 30 minutes.
2. The CI recipe then has you add a bit of water to deglaze the pan and cook for another 30 minutes. Then the rest of the water is added along with the parsley stems, bay leaves, salt, and peppercorns.  The broth is simmered covered for about 15 minutes.  Finally the collard greens, cauliflower, thyme lemon grass, and scallions are added.  The broth is simmered for another 15 minutes.  Lastly, the vinegar is added.
3. In contrast, the newer recipe skips the deglazing/braising step, and just directly adds all the water along with the cauliflower, squash, bay leaf, salt, and peppercorn.  The broth is brought to a boil and then simmer uncovered for about 30 minutes.  Next the collards and parsley are added and simmer for 10 minutes. Finally, the scallions and lemongrass (or lemon) are added and they are steeped in the hot broth for about 5 minutes.
4. The final step for both recipes is to strain it.  The earlier recipes explicitly says to not push on the solids when straining, but the newer recipe omits this instruction.

The only major ingredient that is present in the new recipe but not in the original recipe is winter squash.  A side note on the Anson Mills recipe explains: “If ’tis not the season for winter squash, feel free to omit it. The squash isn’t a make-or-break proposition for this recipe, but its glycerin contribution offers a silky weight and density to the body of the broth as well as a softly, sweet floral counterpoint to the other vegetables.”

Another interesting difference is that the amount of veggies are about the same, but the amount of water used (and therefore the amount of broth produced) is almost double in the newer recipe.  Odd.

My notes

The author also says that  “vegetables must be added at intervals along the cooking process to build flavor and keep flavors fresh.” What a pain.  Maybe they’re right but I’m usually a pretty lazy cook when it comes to making vegetable broth.  When recipes say to roast vegetables first, or add them one at a time, I usually close the book and just do it my own, lazy way.

Another problem with this recipe is that it feels really wasteful (and expensive).  I know that commercial vegetable stock is not worth buying, but I can almost never convince myself it’s worth wasting all that food to make just 1-2 quarts of vegetable broth.  (Maybe that’s why commercial broth is so bad–it would be too expensive to make a decent broth?)

Rather than wasting all my lovely vegetables on broth, I usually use the scrap-based broth method.  I’m sure my resulting broth is not as good as ones that call for 5 pounds of fresh veggies, but it turns out good enough for me.  The scrap-based method works particularly well if you have a veggie-heavy diet and some extra freezer space. Whenever I cut up any veggies (or have extras that I’m not going to be able to use up) I throw the scraps into a quart-sized ziploc bag in the freezer.  If I’m freezing whole veggies I try to chop them up first, because I don’t want to deal with chopping frozen or defrosting veggies. When I get two quart bags worth of veggies and also have some veggies to use up in the fridge I haul out my 8-quart stockpot and make a pot of veggie broth.  I just throw all the scraps in the pot, add water to cover, and boil until the veggies looks spent.  Sometimes I also add a bay leaf, peppercorns, or other spices.  I rarely add salt because it makes it more difficult to follow recipes.  Then I strain it, let it cool, and freeze it in small amounts or in ice cube trays.

Note that vegetable broth (for some reason) does not last long in the fridge.  Unlike many soups, it seems to go sour after 3 or 4 days.   If you cool it quickly (e.g., in an ice bath or by dividing into small containers to cool) it will probably last the longer amount of time, but if you just pour it into a large bowl and let it cool on the counter, it will last fewer days.

There’s a lot of info online about which vegetables to add (or not add) to homemade vegetable broth (like this list from Jennifer’s Kitchen). I couldn’t find anything definitive, but below are my best guesses based on what I’ve read and my own experiences. Obviously, how a veggie will work will depend on what other veggies you’ve added.  A little broccoli might be good, but not if you’ve added cauliflower already.  Parsnips might be delicious, but in combination with a bunch of carrots they might make the broth too sweet.  Let me know if you have any tips of your own, or if I missed any veggies on my list.

The recipe author above, whatever her name, says that a vegetable broth with real depth and flavor must include not only the sweet vegetables (onions, leeks, shallots, carrots, and cabbage), but also more veggies with more intense flavors.  She prefers cauliflower, collard greens, celery, and parsley, but other recipes call for turnips, fennel, bell peppers, or broccoli.

One last impotant note: whatever you add, it should be reasonably fresh.  Textural issues are fine.  You can add a limp carrot that just got dried out because you didn’t put it in a bag, or slightly tough mushrooms, but don’t add anything that looks like it might taste bad.  Try to anticipate ahead of time which vegetables you will have too much of, and freeze them before they start looking sad and old. For example, I can almost never finish a whole head of celery, so I almost always freeze a few of the tougher outer stalks as soon as I get home from the store.

onions, shallots, scallions	Onions are a part of every broth recipe. You can also use onion scraps. The “hairy” root ends seems to be okay if it’s reasonably clean and not moldy, and a slightly greenish outer layer is fine, but many people say that onion peels make the broth bitter. I’m can’t confirm this 100% but I suspect they’re correct. The peels definitely make the broth a nice dark color.  The recipe above call for scallions, but say to add them towards the end of cooking, not sure why.
leeks	Lots of recipes call for leeks. The recipes above say to just use the white and light green parts. Thomas Keller’s French Laundry broth recipe also says white parts only. I have no idea why. The dark green tops aren’t edible but are perfect for broth, in my opinion. I always save my leek tops for broth. The “hairy” bottom parts also seem fine, if they’re not full of mud.
celery	Celery of some sort is essential. Most Americans use stalk celery, but in Europe they seem to use celery root / celeriac. The outside of the celeriac usually has all kinds of dirt in its crevices, so people usually peel it first. Some people say the outer green celery leaves make the stalk bitter, but I can’t say one way or the other. My inclination would be to add just a few of the leaves towards the end of cooking. Or use the inner yellow leaves.
garlic	Most recipes call for it.
mushrooms	The recipes above don’t call for mushrooms, but lots of other recipes do. They make the broth darker and more “meaty” (or so I’m told). I often don’t use up mushrooms fast enough and they start to get a little dried out. Throw them in the freezer at that point (before they get slimy). They’re perfect for broth. Mushroom stems are also good, as are mushroom stalks and dried mushrooms.
carrots	Most broth recipes call for carrots, and they add a nice sweetness, but don’t go overboard. I think an excess of carrots is one of the things that makes most commercial broths taste so awful. Overly sweet broth is gross. Save the tops of carrots that you cut off, or carrot peels, for broth. I’ve heard the celery greens make the broth bitter, but I haven’t tried it myself.
parsnips and parsley root	Parsnips are similar to carrots I think, but add a more interesting sweet complexity. Unlike carrots, I’ve never added too many parsnips to a broth. So always save the tops or peels in the freezer for broth.  Parsley root, on the other hand, I find adds a strong slightly bitter note to stock.  If you use it, I would use only a very small piece, or maybe the peels from one root.
parsley	Many recipes call for parsley. I almost always save my parsley stems for broth. If I have extra parsley leaves that I won’t use up in time, I freeze them.
bell peppers	Lots of recipes call for them. I’ve never tried it. I could imagine that they could add both sweetness and some complexity.  I wonder if you can add the bell pepper insides with the seeds?
tomatoes	Again, lots of recipes call for them, or for tomato paste. I’ve never tried it.
cauliflower, collards, kale, broccoli, cabbage, radishes, turnips, rutabagas	Most recipes say to beware of crucifers, as they add bitterness and sulfer notes. A little bit, however, seems to add complexity and depth of flavor, especially cauliflower and collards (see above).  I sometimes save the hard cauliflower cores in the freezer (but lately I’ve just been eating them).  Veganyumyum, calls for broccoli in her broth. I’ve never tried it myself. James Peterson, in his book Splendid Soups, calls for turnips.  I’ve read that when used sparingly they add some useful complexity, but be careful not to overdo it. I’ve never tried them myself.
winter squash and sweet potato	Apparently winter squash (with the goop and seeds) adds a nice viscosity and some sweetness. I always save any peels with the seeds and goop from the squash in the freezer. Veganyumyum uses sweet potatoes.  If I peel sweet potatoes I’ll save the peels, but I’m not sure how much flavor they add. I think once I had a ton and the broth ended up quite sweet, but in a nice way.
potatoes	No idea. I’ve seen recipes that call for them. I’ve never used them. I can imagine that the peels add a nice earthiness, but I almost never peel my potatoes so I don’t have extras around for stock.
zucchini and summer squash	I’ve never noticed any particular flavor from these. Probably won’t hurt.
fennel	Thomas Keller calls for it in his vegetable stock recipe in the French Laundry Cookbook, and James Peterson, in his book Splendid Soups, calls for the greens or the entire bulb. I always toss the fibrous top stems of the fennel, the root end, and any leftover greens in my freezer bag.
corn	I’ve used corn cobs to make broth before. It’s a great way to extract all that flavor that stays behind when you cut off the kernels.
green beans	No idea. Probably not much flavor?
green peas	I’ve never tried adding peas but I’ve made a broth for pea soup with the shelled pea pods, and it tasted good–like peas. I’ve never tried adding them to my regular broth though.
asparagus	Personally, I don’t like being surprised by asparagus pee when I didn’t even eat asparagus, so I never add it. I don’t recall how it affects the flavor.
spinach, chard, or beet greens	no idea
beets	Everyone says it makes the broth red. Not sure what they add in terms of flavor.
apple and pear cores	My sister makes a pho recipe that calls for a ton of green apples. Now I save my leftover apple and pear cores for my stock.
kombu	Supposedly adds umami. I think I can tell the difference, but it’s subtle.
soy sauce	Probably adds umami, but I’ve never tried it.
lemongrass or a halved lemon	According to the recipe above, adds a “clean, refreshing note” But I don’t know why they have you add the lemongrass so late. I’d think you’d want to simmer it longer. If it’s too strong then why don’t they just call for half a stalk?
white wine or rice vinegar	Wine seems to add a little acidity, and seems to be added in the last 10 minutes of cooking. If you roast your veggies though, you can use the wine to deglaze your roasting pan. Vinegar seems to serve the same purpose, but is usually added after straining.
herbs	Other than parsley and bay leaf, I’ve seen recipes that call for thyme and rosemary. Probably any herb could be good, but would make your broth a little less versatile. For example, you’re going to be using the broth to make saffron risotto, cilantro in the broth may make it taste too Mexican.
spices	The most common additions seem to be peppercorns and cloves, but Thomas Keller calls for curry powder in his recipe for mushroom stock!  I’ve made a recipe for Indian matzoh ball soup by Floyd Cardoz that calls for ground fenugreek and coriander seeds.  Some people add salt to their broth, and perhaps it brings out more flavor from the veggies, but I never do because I want to be able to follow recipes that call for salt without making an adjustment.

Leek and mushroom broth
This recipe is in Georgeanne Brennan’s cookbook France: the vegetarian table. It makes a rich, all-purpose vegetable broth. Although the flavor is substantial, there are no dominating flavors here.

• 1/2 pound cultivated white mushrooms or 1/4 pound cultivated mushrooms and 1/4 pound shiitake, chanterelle, or oyster mushrooms (all coarsely chopped)
• 4 carrots, cut into 2-inch lengths
• 2 large leeks, cut into 2-inch lengths
• 2 yellow onions, quartered
• 1 large celery stalk, cut into 2-inch lengths
• 5 whole cloves
• 2 quarts water
• 1 tsp. salt

Combine all the ingredients in a pot.  Bring to boil over medium-high heat.  Cover, reduce the heat to low, and simmer until the vegetables have imparted their flavor to the broth, 45 minutes to 1 hour.  Strain the broth through a fine-mesh sieve.  Makes 1.5 to 2 quarts.