Protocol: Perpetual Vegetable Stock (Crockpot)

Category: sauces Tags: #low-mess #slow-cooker #base #zero-waste Version: v0.1 Created: 2025-12-29 Yield: continuous (~1–2 L per draw) Prep time: 10 min initial, 5 min per replenishment Cook time: 8–12 hours initial, then continuous Tools: slow cooker (crockpot), fine-mesh strainer, ladle, storage containers

Goal / Why this exists

A zero-waste perpetual stock system that runs continuously in a crockpot. Draw off stock as needed, replenish with vegetable scraps and water weekly. The stock deepens in flavor over time. Perfect for using up vegetable trimmings and always having fresh stock on hand.

Note: This version includes beef fat, making it a hybrid vegetable-beef stock with richer body.

Ingredients (Initial Batch)

Aromatics (what you have)

• 2 yellow onions, quartered (~400 g)
• 2 carrots, rough chopped (~200 g)
• beef fat/tallow (~30–50 g)

Recommended additions (as available)

• 2–3 celery stalks with leaves (~150 g)
• 4–6 garlic cloves, smashed
• 1 bay leaf
• 5–6 whole black peppercorns
• 3–4 parsley stems
• 1 sprig fresh thyme

Liquid

• water to cover vegetables by 5 cm (~2–3 L)

Weekly replenishment (ongoing)

• vegetable scraps: onion ends, carrot peels, celery ends, leek greens, mushroom stems, fennel fronds, herb stems
• fresh water as needed

Method

Initial setup

1. Add beef fat to crockpot, let it melt on LOW (5 min).
2. Add onions and carrots, toss to coat in fat.
3. Add any additional aromatics (celery, garlic, herbs, peppercorns).
4. Cover with cold water by 5 cm.
5. Set crockpot to LOW.
6. Cook 8–12 hours for initial batch.

Drawing stock

1. Ladle out stock through fine-mesh strainer as needed.
2. Never draw more than 50% of liquid at once.
3. Immediately replenish with equal amount of fresh water.

Weekly replenishment cycle

1. Add collected vegetable scraps (100–200 g).
2. Top up water to maintain level.
3. Remove any vegetables that have been in >2 weeks (they’ve given all their flavor).
4. Optional: add a pinch of salt (2–3 g) to maintain seasoning.

Maintenance schedule

• Daily: Check water level, top up if low.
• Weekly: Add scraps, remove spent vegetables.
• Monthly: Strain entire pot, clean crockpot, restart with fresh aromatics + reserved liquid.

Success criteria

• Clear to slightly cloudy golden-brown color
• Clean savory aroma, no off/sour smells
• Well-balanced umami flavor without bitterness
• Slight body from gelatin (if using bones) or fat

Vegetables to ADD (good for stock)

• Onions, leeks, shallots (skins add color)
• Carrots, parsnips
• Celery, fennel
• Mushrooms (especially stems)
• Tomato paste or tomato scraps (small amounts)
• Garlic
• Fresh herb stems (parsley, thyme, dill)
• Corn cobs
• Pea pods

Vegetables to AVOID

• Brassicas (cabbage, broccoli, cauliflower, Brussels sprouts) — sulfurous, bitter
• Beets — will turn stock magenta
• Potatoes — makes stock cloudy/starchy
• Peppers (bell or hot) — can dominate flavor
• Artichokes — bitter
• Anything moldy or rotten

Troubleshooting

Problem	Cause	Fix
Sour smell	Bacterial growth	Discard, clean pot, restart
Bitter taste	Brassicas or overcooked aromatics	Remove bitter veg, add fresh
Weak flavor	Too much water, too few aromatics	Reduce liquid, add more veg
Cloudy stock	Boiled too hard, starchy veg	Keep on LOW only, avoid potatoes

Safety notes

• Keep crockpot on LOW or WARM continuously — never let stock sit at room temperature.
• If power goes out >2 hours, discard and restart.
• Trust your nose: any off smells = discard immediately.
• Monthly full restart prevents flavor degradation and ensures food safety.

Variations

• Roasted vegetable stock: Roast aromatics at 200°C/400°F for 30 min before adding to pot for deeper flavor.
• Mushroom-forward: Add 50 g dried porcini or shiitake for umami boost.
• Asian-style: Add ginger, star anise, and scallion greens.
• Pure vegetarian: Omit beef fat, use olive oil or skip fat entirely.

Storage

• Drawn stock keeps 5 days refrigerated.
• Freeze in 500 mL portions for up to 6 months.
• Ice cube trays work well for small portions.

Linked runs

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