Mushroom-Kombu Broth.
The dark, savory broth that does the job of beef stock, chicken stock, and dashi. Two hours, mostly walking away. Three liters that hold a month.
This is the broth that does the job of three. It replaces beef stock in a bourguignon, chicken stock in a risotto, and dashi in a bowl of ramen. One Saturday morning of mostly-walking-away time, three liters of broth, a month of dinners.
I learned the move from chef Tetsu in Sapporo in November 2020 — not from him directly, but from the back-of-house wall where he had taped the standing instruction for the prep cook arriving at 6 a.m.: 昆布 6 時, 椎茸 6 時 5 分, 玉ねぎ 炭にしてから入れる. Kombu at 6:00. Shiitake at 6:05. Onion blackened before it goes in.
The charred onion is what makes this broth look like meat stock. Most recipes online skip it, because most recipes online are written by people who have never had to make a vegan broth look credible across a serving table. The black-on-the-cut-surface onion gives the broth a mahogany color that doesn’t read as “vegetable stock.” Don’t skip and don’t go pale.
What’s in the jar
A 3-liter batch yields exactly twelve 250 mL jars (or six 500 mL jars). I keep four in the fridge for the week and freeze the rest in quart-size freezer bags, flat. Flat-frozen bags stack vertically in the freezer drawer like books on a shelf — far more space-efficient than jars.
The economics
Cost per batch, January 2026 prices, Washington DC:
- Dried shiitake (40g): $4.20
- Kombu (20g): $1.80
- Cremini (1 lb): $5.00
- Other vegetables: $3.00 (or zero if you save vegetable scraps in a freezer bag — see below)
- Total: ~$14 for 3 liters.
That’s $1.17 per cup of broth. Compare to store-bought “vegetable broth” at ~$1.50–$2.50 per cup that tastes like nothing. Compare to demi-glace at $8/cup. This is the cheapest good broth in any kitchen.
The vegetable-scrap trick
Keep a one-gallon freezer bag in the freezer marked “stock.” Every time you prep vegetables, the trimmings go in: onion ends, carrot peels, celery tops, parsley stems, mushroom stems, leek tops. The bag fills in about three weeks of normal cooking. When it’s full, you’re ready to make stock — and the cost of the vegetable component is zero. The kombu and shiitake are the only things you actually buy for the recipe.
When this can fail
- You boiled the kombu. The broth smells faintly fishy and looks cloudy. Fix: never let kombu hit a hard boil. Remove it at the 30-minute mark if your simmer is even slightly aggressive.
- You skipped the char. The broth tastes thin and looks pale. There’s no fix — char next time.
- You over-reduced. You went two and a half hours and the broth is now bitter and dark. Fix: dilute with water until the bitter edge softens, season more aggressively to compensate.
What this enables
Read the linked recipes below — each one is built on this broth. Make the broth once on a Saturday. Eat from it for the next three weekends.
Cook fast on a Tuesday because you did this on a Sunday.
You'll need
Ingredients
For 1 servings · 14 items
The base
Added at the end
The method
Method
6 steps · check as you go
What this enables
Questions, honestly answered
FAQ
QCan I use this broth wherever a recipe calls for beef or chicken stock?
Yes, in 9 of 10 cases. The mushroom-kombu broth has the dark color, the body, and the umami depth that lets it replace beef stock in a bourguignon or coq au vin, replace chicken stock in a risotto or onion soup, and replace dashi in a ramen tare. The one place it falls short is delicate light-poultry stocks for a clear consommé — for that, use a lighter vegetable stock without the kombu and shiitake.
QHow long does it actually keep?
Five days in the fridge, three months in the freezer at -18°C. After three months in the freezer it doesn't go bad, but the brightness fades. I label every jar with the date and rotate. The mushroom flavor is best in the first 8 weeks.
QCan I make this with fewer ingredients?
Yes, in a pinch. The non-negotiables are kombu, dried shiitake, and the charred onion — those three carry 70% of the flavor. Drop the parsley, the celery, the carrots if you must. Do not drop the kombu or the shiitake; without them you have a thin vegetable broth, not the dark stock this is meant to be.
QWhy dried shiitake instead of fresh?
Dried shiitake has 10 to 20 times the umami content of fresh. The drying process concentrates the guanylate compounds that combine with the glutamates in the kombu in a synergistic way — the two together are more savory than either alone, by a factor that food scientists call 'superadditive.' Fresh shiitake is excellent for cooking; for stock, dried is the only choice.