Costmary (Tanacetum balsamita), also called Bible leaf or alecost, is one of the most obscure herbs in Western culinary history. Its large, oval leaves have a complex, layered flavor: refreshing mint-like coolness, a hint of balsam or camphor, slight bitterness, and a faint spearmint or chrysanthemum-like quality. It was widely used in medieval European cooking — in ales (hence "alecost"), stews, salads, and stuffings — and was brought to the Americas by early colonists, but fell out of fashion over time.
Today, costmary is almost exclusively found in heritage herb gardens and specialty plant nurseries. It's rarely stocked dried in spice shops, making substitutions almost always necessary for anyone who encounters it in an old recipe. Its complex mint-balsam flavor profile means no single herb is a perfect match, but the minty and slightly camphor-like elements can be approximated.
When costmary appears in historic recipes, it typically plays a role similar to mint — providing freshness and cooling contrast in rich dishes — but with more complexity and slight bitterness. Substitutes should lean toward that profile.
■Best Substitutes for Costmary
| Substitute | Flavor Match | Swap Ratio |
|---|---|---|
| Dried spearmint | Closest mint-cool match | 1:1 |
| Dried mint + dried sage (small amount) | Adds balsam depth to mint | 3 parts mint to 1 part sage |
| Dried chrysanthemum leaf (if available) | Similar floral-bitter quality | 1:1 |
| Dried tarragon | Herbal, slightly bitter, anise hint | Use ¾ the amount |
| Fresh mint + lemon balm | Adds cooling and gentle citrus | Equal parts, same total amount |
| Dried southernwood (tiny amount) | Bitter, camphor-herbal | Use ½ the amount |
| Simply omit (in most modern recipes) | Practical when exact flavor not critical | N/A |
■How to Choose the Right Substitute
For stews, stuffings, and roasted meats where costmary provides background herbal freshness, dried spearmint is the most practical substitute. It misses the balsam-camphor note but delivers the cooling, slightly sweet mint quality that makes costmary valuable in rich dishes. Combining spearmint with a very small amount of dried sage approximates the more complex, slightly resinous character better.
In historic ale or mead recipes where costmary was used as a bittering and flavoring agent (before hops became standard), a combination of dried yarrow and a few dried mint leaves can replicate its role. For salads and fresh herb applications, lemon balm paired with fresh mint makes a pleasant modern adaptation of costmary's fresh, cooling flavor.
■Frequently Asked Questions
What can I substitute for costmary in a medieval stuffing or forcemeat?
Dried spearmint combined with a small pinch of dried sage works well. Use about the same total amount as the recipe indicates for costmary. The combination gives you the mint freshness and herbal depth.
What can I substitute for costmary in homemade ale or mead?
Dried yarrow is the most historically accurate substitute for costmary's bittering role in ale. A small amount of dried hops also works, though hops are stronger — use about half as much as you would costmary.
Can I leave out costmary entirely?
Yes, especially in modern adaptations of historic recipes. Costmary plays a supporting herbal role and its absence rarely ruins a dish. The flavor will be slightly less complex and fresh, but other ingredients will compensate.
Where can I buy or grow costmary?
Dried costmary is nearly impossible to find commercially. Growing it is the most reliable option — it's a vigorous perennial that spreads readily once established. Specialty herb nurseries and seed companies (like Richters) carry plants and seeds.
Is costmary related to feverfew or tansy?
Yes — costmary (Tanacetum balsamita) is in the same genus as feverfew (Tanacetum parthenium) and tansy (Tanacetum vulgare). All three share some similar bitter, camphor-like qualities, though costmary is the mildest and most mint-like of the three for culinary use.