Best Spices for Tomato Soup

Tomato soup is seasoned lightly and mostly from the bottom of the pot: onion and garlic cooked in fat, then the tomatoes, then a herb. Three named recipes below agree on that base, and two of the three finish with basil. The interesting differences are in the small touches: a bay leaf, a pinch of red pepper, a spoonful of brown sugar to take the edge off the acid, and cheese on top. This page sets out what each one does and when it goes in.

At a glance

Seasoning	Job	In the recipes below
Onion	Sweet, savory base	All three¹²³
Garlic	Pungent depth	All three¹²³
Basil	The signature herb; sweet, fresh aroma	Two of three¹³
Bay leaf	Background herbal note in the simmer	One²
Red pepper (ground or flakes)	A little heat	Two of three¹²
Brown sugar	Tones down acidity	One²
Parmesan or other cheese	Salty, savory topping	One³
Chives	Fresh finish	One²
Thyme	Optional savory herb	None of the three

Three recipes side by side

	USDA Tomato Basil Soup¹	Cook’s Illustrated Creamless Creamy Tomato Soup²	Massachusetts WIC Cheesy Tomato Soup³
Tomatoes	1 can (14 1/2 oz), drained	2 cans (28 oz) whole, in juice	4 cups cherry or grape tomatoes
Fat	1 tbsp olive oil	1/4 cup extra-virgin olive oil	2 tbsp olive oil
Onion	1 medium	1 medium	1
Garlic	2 cloves (or 1/4 tsp garlic powder)	3 cloves	3 cloves
Herbs	1 tsp dried basil	1 bay leaf; 1/4 cup chopped chives to finish	2/3 cup fresh basil or 1 tbsp dried
Heat	1/8 tsp ground red pepper	Pinch of red pepper flakes (optional)	None
Other	Nonfat dry milk; salt and pepper optional	1 tbsp brown sugar; bread for body; brandy optional; salt and pepper	Broth; whole wheat toast; Parmesan or mozzarella on top

These are the publishers’ recipes, not a house standard.

The core seasonings and what each one does

Onion and garlic: the base

All three recipes start by cooking onion in olive oil, then add garlic before the tomatoes.¹²³ The USDA recipe browns the onion for about four minutes and gives the garlic one minute more;¹ garlic goes in after the onion because it will quickly burn and turn bitter if it cooks too long, as America’s Test Kitchen explains.⁴ Britannica describes garlic’s powerful, onionlike aroma and pungent taste.⁵ The USDA recipe allows 1/4 teaspoon of garlic powder in place of two cloves.¹ See garlic powder vs. garlic and onion powder vs. onion.

America’s Test Kitchen chose olive oil over butter for this step after finding that butter muted the tomato flavor.²

Basil: the usual herb

Two of the three recipes are built around basil.¹³ PROSEA describes sweet basil’s aroma as soothing, sweet-spicy, slightly green and fresh.⁶

When it goes in depends on the form. The LSU AgCenter groups basil with the delicate herbs that lose flavor under prolonged heat;⁷ the WIC recipe tops each bowl with fresh basil.³ The University of Delaware’s extension guide says dried herbs are stronger than fresh.⁸ Even so, the USDA recipe adds its dried basil only at the end, with the milk, heating the soup without boiling it.¹ For a long-simmered pot, Delaware’s guide suggests adding herbs during the last 45 minutes.⁸ See dried vs. fresh basil and too much basil.

Bay leaf: one, simmered and removed

The Cook’s Illustrated recipe uses a single bay leaf for two large cans of tomatoes.² Bay leaves come from Laurus nobilis, the bay laurel of the family Lauraceae.⁹ In one analysis of the leaf oil, 1,8-cineole (31.9%), sabinene and linalool were the main components.¹⁰ J. Kenji López-Alt, speaking to The Splendid Table, says bay brings out the meaty flavors of beef and chicken; that is a cook’s observation, not a measured effect.¹¹ Fish the leaf out before blending or serving: López-Alt likens eating one to eating a fish bone.¹¹ See cooking with bay leaves and too much bay leaf.

A little heat

The USDA recipe uses 1/8 teaspoon of ground red pepper, which it calls a pinch; Cook’s Illustrated offers an optional pinch of red pepper flakes.¹² At these amounts the job is a faint warmth, not heat. See red pepper flakes and cayenne pepper.

Brown sugar: balancing the acid

Cook’s Illustrated adds a tablespoon of brown sugar and explains that a little brown sugar toned down the acidity.² Taste before adding any; the other two recipes use none.

Cheese and the savory side

The WIC recipe tops each bowl with shredded Parmesan or mozzarella.³ Tomatoes and cheese share a savory side: FDA notes that MSG occurs naturally in many foods, such as tomatoes and cheeses,¹² and Britannica lists tomatoes and cheese among foods with a natural umami taste.¹³ A grilled cheese sandwich alongside the bowl is a familiar American pairing (common practice).

Thyme: optional

None of the three recipes uses thyme. It is a reasonable addition if you want a more savory soup: its character comes from thymol and carvacrol in its oil,¹⁴ and America’s Test Kitchen classes it as a hearty herb to add early in cooking.¹⁵ Use a light hand; a sprig or a pinch of dried is plenty for a pot of this size (our starting point, not a tested amount). See fresh vs. dried thyme and too much thyme.

When to add what

Seasoning	When	Source
Onion, then garlic	Start, cooked in olive oil	All three recipes¹²³
Dried basil, red pepper	End, with the milk	USDA¹
Fresh basil, cheese	On top, at serving	WIC³
Chives	To finish	Cook’s Illustrated²

“Tomato Basil Soup”, USDA Food and Nutrition Service, via MyPlate. myplate.gov · Regulator ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³
“Creamless Creamy Tomato Soup”, Cook’s Illustrated, America’s Test Kitchen, 2008. americastestkitchen.com · Publication ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴
“Cheesy Tomato Soup”, Massachusetts WIC Nutrition Program. mass.gov · Regulator ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹
Liz Bomze, “Why You Should Wait to Add Garlic”, America’s Test Kitchen, 2023. americastestkitchen.com · Publication ↩
“Garlic”, Encyclopaedia Britannica, 2026. britannica.com · Reference work ↩
Aguilar, Pham and Oyen, “Ocimum basilicum”, PROSEA. uses.plantnet-project.org · Reference work ↩
“Flavorful Herbs”, LSU AgCenter. lsuagcenter.com · Reference work ↩
“Using Herbs and Spices”, University of Delaware Cooperative Extension, revised 2025. udel.edu · Reference work ↩ ↩²
“Laurus nobilis L.”, Plants of the World Online, Royal Botanic Gardens, Kew. powo.science.kew.org · Reference work ↩
Caputo et al., “Laurus nobilis: Composition of Essential Oil and Its Biological Activities”, Molecules, 2017. mdpi.com · Peer-reviewed ↩
David Leite with J. Kenji López-Alt, “Bay leaves are an optional ingredient”, The Splendid Table, 2014. splendidtable.org · Publication ↩ ↩²
“Questions and Answers on Monosodium glutamate (MSG)”, U.S. Food and Drug Administration. fda.gov · Regulator ↩
“Umami”, Encyclopaedia Britannica, 2026. britannica.com · Reference work ↩
S.H. Widodo, “Thymus vulgaris”, PROSEA. uses.plantnet-project.org · Reference work ↩
Liz Bomze, “Our Guide to Fresh Herbs”, America’s Test Kitchen, 2019. americastestkitchen.com · Publication ↩

Tomato Soup Spices: Onion, Garlic, Basil and the Small Touches That Balance the Acid