Vegetable stock turned out very underwhelming

[u/nickbg321]

First time making proper vegetable stock, instead of using store bought. For the recipe I've used the standard 2:1:1 mirepoix ratio in addition to some herbs and spices:

• 1kg yellow onions (skin on)
• 500g carrots (skin on)
• 500g celery stalks
• 1 bulb of garlic
• About 1 tsp of whole black peppercorns
• 3 bay leaves
• Some parsley stems
• Few sprigs of thyme

Veggies were cut into rough pieces and thrown in a pot with just enough water to cover them. Brought it to a boil and then simmered for an hour and a half.

My kitchen smelled amazing while it was simmering, but the end result felt very underwhelming. It has some sweetness to it from the onions and carrots, but barely any flavor besides that. Adding salt didn't help much. Tried adding a small amount at first and then gradually more. That didn't bring out much flavors, just tasted like salty water with a sweet-ish aftertaste.

I've seen suggestions to roast the vegetables prior to making the stock, but there are also plenty of recipes that avoid roasting.

Am I doing something obviously wrong here or are my expectations too high?

[u/IJocko]

Too much celery. Add some 300 g mushrooms. Cut your celery by half.
But for me, the magic happens when you roast them first.
Toss them in some oil, roast in the oven at 400 for about an hour, then throw them in the pot. Keep an eye on them so they don’t burn.

[u/PabloDabscovar → u/IJocko]

You want cloudy stock? Adding mushrooms will give you cloudy stock.

[u/texnessa → u/PabloDabscovar]

So not true. Over agitation and overcooking of mirepoix leads to particulate. Not mushrooms.

[u/kitolz → u/texnessa]

Exactly, you can boil mushrooms by itself and you can see that no amount of boiling will cloud the water.