Should You Soak Beans Before Cooking?
Soaking isn't strictly necessary but offers benefits: shorter cooking time (by 25-50%), more even cooking, and possibly reduced gas-causing compounds. For most beans, you can skip soaking if you have time to cook longer—many cooks and chefs cook beans from dry without issue. Kidney beans should always be boiled (soaked or not) to destroy a toxin.
Key Takeaways
- Soaking rehydrates dried beans, reducing cooking time.
- Red kidney beans contain a toxin (phytohemagglutinin) that requires boiling—don't slow-cook raw kidney beans.
- Lentils, split peas, and black-eyed peas don't need soaking—they cook quickly regardless.
Explanation
Soaking rehydrates dried beans, reducing cooking time. An overnight soak (8-12 hours) or quick soak (boil 2 minutes, then soak 1 hour) achieves similar results. Soaking also allows beans to cook more evenly—unsoaked beans may have a creamy outside with a harder center.
The gas question is debated. Some oligosaccharides (gas-causing sugars) do leach into soak water, but the effect varies by bean type and person. Draining soak water and using fresh cooking water may help. Your body also adapts to eating beans regularly, reducing gas over time.
Many professional cooks skip soaking, arguing slow cooking produces better texture. Rancho Gordo (famous bean company) recommends no soaking for fresher beans. Older dried beans benefit more from soaking. Test what works for you.
Cooking times vary dramatically by bean type and whether you soak. Black beans take about 60-90 minutes unsoaked versus 45-60 minutes soaked. Chickpeas require 90-120 minutes unsoaked versus 60-90 soaked. Large lima beans and cannellini beans are among the longest cooking, needing up to 2 hours unsoaked. A pressure cooker like an Instant Pot cuts all these times roughly in half, making the soaking step even less necessary for time-saving purposes.
The age of dried beans matters more than most people realize. Beans from the current harvest year cook in about half the time of beans that have been sitting on a shelf for 2-3 years. Old beans have lost moisture through their seed coat and may never fully soften regardless of soaking. If you buy from bulk bins with high turnover or specialty retailers like Rancho Gordo or Zürsun Idaho Heirloom Beans, you get fresher product. Check for a harvest date if available, and store dried beans in airtight containers in a cool, dark place to preserve quality.
Things to Know
- Red kidney beans contain a toxin (phytohemagglutinin) that requires boiling—don't slow-cook raw kidney beans.
- Lentils, split peas, and black-eyed peas don't need soaking—they cook quickly regardless.
- Adding salt to soak water is controversial; some say it toughens skins, others find no difference.
- Very old dried beans may never soften no matter how long you cook them.
- Adding a small piece of kombu seaweed to cooking beans is a traditional Japanese technique believed to reduce gas-producing compounds and add umami flavor.