Lactarius Indigo mushroom looks out of place in nature. It is blue, really really blue. When sliced with a knife, it stains an even darker blue. Truly one of the most interesting mushrooms I’ve ever seen, let alone eaten.
The first time I saw one I was blown away, such a color from something in nature is really remarkable. The amount of truly blue foods in the world is pretty slim, and these have to rank among the most interesting. The caveat was every time I would find these for the first couple years they were always past prime and bug eaten, which is pretty typical for Lactarius mushrooms.
I got lucky one day after a massive rainfall in a park where I compete with the Russian ladies for mushrooms (they love pine forests). Out of the corner of my eye I spotted a mushroom under the pine trees, and when I stopped to pick it up, I noticed more, and then more around them.
Long story short, the key to finding indigo milkcaps is timing. From my experience Lactarius species need a lot of rain to produce a decent fruiting, so after you’ve found a place where one or have been spotted, make sure to go there after a good rainfall, and you might get lucky.

They stain a dark blue
Habitat
I have only found them under Eastern White Pine where I live, typically starting to fruit in late to mid August. That being said, if you find a coniferous forest where you know milkcaps grow, you might want to check back from time to time to see what comes up.
Cooking
These are relatively clean mushrooms, just check for the occasional pine needle. The big problem here is that bugs like these guys, and more than likely what you find may be past prime. You could make some stock out of the buggy ones, but there are so many other nice mushrooms out there that I only take really nice milkcaps home.
In the kitchen, these will turn slightly grey as they cook in oil or fat. The color will not be totally gone, but it will definitely be muted and very hard to see, definitely not vibrant. To get around this, I’ve had good sucess stewing them, basically keeping them very moist and not letting them touch the bare pan with oil, then marinating with herbs, garlic, and vinegar. You could blanch them quickly in salted water if you like, too which should also retain the color, citric acid like lemon juice, or acid like vinegar has an ability to retain colors though, and works very well if you want to keep them blue.
But, retaining the color by blanching or pickling does mean that you have to sacrifice the depth of flavor that comes from browning in a pan with heat though.
For more on that, check out my method for blanching them in pickling liquid to keep the color and then packing them in flavorful oil-here’s the recipe Lactarius Indigo preserved in “holy oil”.
Preservation
They can be sliced and dried in a dehydrator, and will make a good stock or powder, and young ones make very good pickles. I don’t really like freezing milkcap mushrooms unless I’m making duxelles, and I haven’t ever even found a patch so saturated with these that I would want to make a concentrated preserve like duxelles with them.
Another interesting way to preserve them is not one you eat. Most mushrooms when combined with a mordant can create a colorful dye. So if you want a funky blue dye for something, do a little research and try your hand at it.
Recipes
Recipes I’ve made for Indigo Milkcaps or where they can be substituted
- Catalan Saffron Milkcaps
- Wild Mushrooms With Garlic, Breadcrumbs and Chili
- Wild Mushroom Conserve
- Wild Mushroom Duxelles
- Pickled Milkcaps
- Indigo Milkcaps Preserved In “Holy Oil”
- Turkish Saffron Milkcaps With Cumin Yoghurt
- Fricando Of Veal With Saffron Milk Caps
- Wild Mushrooms With Garlic And Parsley
- Stinging Nettle Tortelli In Lactarius Broth
Just curious about your efforts on the pickling front re: Lactarius Indigo…any success in preserving colour? How was the taste? Thanks for posting this.
Hi James. Yes, Lactarius Indigo can be pickled and it’s color preserved. You need to make sure not to color the mushrooms or saute them though. The vinegar or alternately citric acid preserves their color. They taste great, depending on the spices and pickling mixture you use. Don’t overpack the jars or they’ll get slimy though.
I live in Northwest Arkansas and we find L. Indigo under/near older oak trees in mixed wood forests. My husband and I found ten today, June 13,2016, but we found our first one two weeks ago. I’ve read they can be found here Spring through fall.
Kat
I found about a quart of them, very fresh and 1.5 to 4 inches diameter, roadside under oak and pine trees in northern Virginia on July 8, 2016. Tough to spot because by the time they’re 1.5 inches diameter they’ve barely emerged, about one inch above the ground, pushing up the leaf litter. Knockout blue color
I just found an indigo milkcap on our farm in Missouri. Not real sure what t do with it.
Cook it and eat it if the stem cuts clean.