I am making a hearty vegetable soup in a 5 quart slow cooker. I’m not familiar with using rosemary in dishes and don’t want to ruin the soup. Can someone share with me the amount I should use to help with a hearty flavor?
Rosemary can be a pretty assertive flavor, too much can overpower a dish, so it's better to underdo than overdo it. How to approach that depends on whether you are using dried or fresh. I would highly recommend fresh herbs over dried in most cases, especially with rosemary as it loses almost all of its flavor and more importantly aroma.
Dried rosemary sprigs look attractive, but the leaves don't rehydrate that well and you can end up with hard pointy bits in your end dish. I've had them stick into my gums even after hours of cooking. If you are using dried whole leaves I recommend crushing them up a bit before adding to avoid that. If you do use dried then you should start with half a teaspoon of powdered or 1 teaspoon of dried leaves. Give it some time to blend in then test the flavor. I would add this early on as it gives the herb plenty of time to rehydrate and infuse the food, as well as add more if you aren't getting the flavor.
Fresh rosemary varies in quality, so how much to add partly depends on how fresh and aromatic it is. The best way to use it is to cut a length of sprig and add the sprig in leaves attached, then lift it out later. If some of the leaves fall off then they will be tender enough to eat, if they stay on the twig then you wouldn't want to eat them.
To test for quality rub some of the leaves between your fingers and smell them. If you get a really strong piney smell then it's good stuff, if you get it but it's not powerful then you'll want to add more. For strong rosemary in a large pot of vegetable stew I would add a single finger length sprig to start, with weaker rosemary I'd add double that. I prefer to add fresh rosemary closer to the end of cooking; the longer it cooks the more the dish loses some of the more aromatic qualities.
If you are finding fresh rosemary to be hard to find, it is one of the easiest things to grow. It's hardy and can tolerate a wide variety of conditions, and is fine in a pot.
The amount depends on how much of the other ingredients you are using, and also on your taste.
If you have no guidance from the recipe you are following, you could start with a pinch and check how it tastes like. In case it's too mild/weak for you, add more.
Adding more is usually easier than removing. Source: I have had twice a pizza ruined because of an excessive amount of oregano, which made the entire thing bitter and unpalatable.
I don't think there's an quantifiable answer to this but there a couple of things you can use to get a starting point.
First, how strongly do you want the soup (or any dish) to taste of rosemary? If you want a punchy rosemary and garlic soup, you'll want to add more rosemary than you would if you're just adding a background flavour.
Second, how strong is your rosemary? You perhaps want to add less of the rosemary that you picked fresh from your garden than you do of the slightly sad looking bunch you found in the fridge.
A big thing to remember is "you can always add more but you can't take it out". This applies to any seasoning really. Start with less than you think you need and work upwards
A couple of points:
Aromatic herbs are "driven out" by simmering. That's why a good soup cannot be made by following a recipe: the herbal flavor depends on both the amount of herb and how long the pot has been simmering. In restaurant kitchens, the soup's herbs are constantly adjusted as the evening progresses. Rule: taste it. If it needs more, it needs more. Taste it.
Start slow and add more. Your taste buds get acclimatized by over-frequent tasting. If you find you have added too much, let the pot simmer to dissipate the flavor. Aromatic herbs are smelled, not tasted by the tongue. They evaporate from hot food and thereby become weaker with cooking time
Second, the flavor of herbs varies with the season and the origin. I worked in a craft gin distillery. Juniper is harvested in different parts of the world in different seasons, with different flavor profiles. The recipe needed to be adjusted continually.
This may be the best but also worst answer.
Often, I notice a lot of home cooks tend to be scared of adding too much seasoning. Salt is a different beast, but here, we're not talking about salt, we're talking about herbs. And, the aversion to adding too much, in my humble opinion, actually is a weakness that leaves food bland and cooks unrewarded for their efforts by a tasty final product. But, in any case, yes, there is too much, but there is also too little.
Let's move on the solutions.
So one solution: Try dried herbs. Its hard to go overboard with dried herbs, such as dried rosemary flakes. So, one possible solution is to try dried rosemary flakes first.
Second solution: Dry or fresh, sprinkle enough to generously cover the surface but not blanket the surface, so that when you stir it in, it "looks right". Not so much that its "rosemary soup" but a little here and a little there. Its hard to explain but that should be a reasonable explanation as a rule of thumb. Then, simmer for a little while, and then you taste. If its not potent enough, add more sparingly, stir, simmer for a few minutes, and taste again.
Hope this helps!
Here is my way of finding the right seasoning...
Cook two pots. The big one, season it moderately . The small one, excede in the seasoning.
Try them both when they are done. If the moderate one lacks a bit of taste, then add little by little from the small one.
Once you know better your herbs and your taste, you will be able to season your food right from the start!