Purple hull peas are a low-acid southern field pea. The only research-tested way to can them at home is in a pressure canner: 40 minutes for pints and 50 minutes for quarts, with pressure adjusted for your altitude. A boiling-water bath does not get hot enough to destroy Clostridium botulinum spores in peas, no matter how long the jars sit in boiling water.
That is the whole safety case in one paragraph. The rest of this guide covers the decisions that actually change the jars you open in January: when to pick, raw pack versus hot pack, how loosely to fill the jar, why the liquid turns dark, and why ham hocks belong in the pot later—not in the canner.
What purple hull peas actually are
Purple hull peas are cowpeas (Vigna unguiculata), the same species as black-eyed peas and crowder peas. They are not English garden peas (Pisum sativum). The pods turn burgundy or deep purple when the seeds inside are ready; the shelled peas themselves are usually pale green to cream, often with a pink or purple “eye.”
That botanical difference matters for canning. Extension guides list blackeye, crowder, and field peas as their own category, with longer quart times than green English peas. Purple hull, pinkeye purple hull, Mississippi silver, and similar southern peas belong in that field-pea group.
Fresh, tender, just-shelled peas use the shorter field-pea process. Dried purple hull peas are a different product and need the dried-bean process (hydrate, boil 30 minutes, then 75 minutes for pints and 90 minutes for quarts). Do not mix the two schedules.
Why a water-bath canner is not an option
Peas sit well above pH 4.6. In a sealed jar they create an oxygen-free environment where botulism spores can grow if the food never reaches the temperature a pressure canner produces (about 240°F / 116°C at 10–11 pounds of pressure). Boiling water tops out at 212°F / 100°C at sea level—lower at altitude. Extra hours in a water bath do not close that gap.
Ignore social-media posts that process purple hull peas for two or three hours in a water-bath canner. That method is not approved by the USDA or the National Center for Home Food Preservation.
Electric multi-cookers with a “canning” button are also not a substitute unless the manufacturer has documented that the unit holds tested canning pressure the way a dedicated pressure canner does. Use a weighted-gauge or dial-gauge pressure canner built for home canning.
What you need before you start
- A pressure canner with a rack
- Pint or quart canning jars, new lids, and rings
- Jar lifter, funnel, bubble tool or plastic knife, clean towels
- Large pot for boiling water (and for hot pack, if you use it)
- Canning salt, optional
- Freshly shelled purple hull peas
Wash jars in hot soapy water or run them through the dishwasher. Keep them hot until you fill them. Prepare lids according to the manufacturer’s current directions; most modern lids no longer need to be simmered.
Put 2–3 inches of water in the canner (follow your canner manual) and start warming it so you are not loading cold jars into a cold canner or vice versa.
Pick and shell at the right stage
Harvest when pods are well filled and have turned purple or mottled purple, but before the peas dry down in the hull. Young, tender seeds can better. Overmature peas turn starchy, stay firmer after processing, and throw more sediment.
Shell the same day if you can. Quality drops in the refrigerator, and a pile of unshelled peas left on the porch overnight is an invitation to weevils and fermentation.
Sort as you shell:
- Discard insect-damaged, moldy, or dried-hard peas
- Pull out bits of hull and field debris
- Keep sizes reasonably even so the jar heats uniformly
Wash the shelled peas in several changes of cool water until the water runs mostly clear. Field peas throw a lot of dust and loose seed-coat pigment.
Yield, roughly: A 25-pound hamper of unshelled purple hull peas often shells out to about 4–5 quarts of peas, not a full canner load. Plan on more picking than the “bushel of English peas” charts suggest. Those charts assume thinner garden-pea pods.
Raw pack or hot pack
Both methods are approved for fresh field peas. The difference is quality and jar cleanliness, not safety, as long as you use the correct process time.
Raw pack is faster on a big harvest day. You fill jars with raw peas and boiling water. The tradeoff: peas expand and float, liquid can siphon, and a gray foam that field peas release during heating can end up inside the jar.
Hot pack means covering the peas with water, bringing them to a rolling boil, then packing them hot. Many canners prefer this for purple hull peas because the first wave of foam and scum can be skimmed off in the pot instead of sealing it into the jar. Hot pack also drives out air, so jars often have less floating and a slightly fuller look after processing.
If the peas are very fresh and you want maximum firmness, raw pack works. If you want cleaner jars and don’t mind an extra pot, hot pack is the better everyday choice.
How full to pack the jar
Starchy peas swell. If you ram them down, they can pack so tightly that heat does not move through the center of the jar.
Mississippi State University Extension’s field-pea directions are the most specific on fill level:
| Pack style | Pint fill | Quart fill | Then cover with liquid to |
|---|---|---|---|
| Raw pack | Peas to 1½ inches from the rim | Peas to 2 inches from the rim | 1 inch headspace |
| Hot pack | Peas to 1½ inches from the rim | Peas to 1½ inches from the rim | 1 inch headspace |
Do not shake or press the peas down. After adding liquid, slide a plastic bubble tool around the inside of the jar and add more boiling water if the level drops.
Salt is optional and only for flavor. Typical amounts: ½ teaspoon per pint, 1 teaspoon per quart. It does not make the food safer.
Do not add bacon, ham hock, fatback, onion, or flour to the jar. Those extras change density and heat penetration. There is no USDA-tested recipe for “purple hull peas with a piece of pork in the jar.” Can the peas plain. Add smoked meat when you open the jar.
Step-by-step: canning fresh purple hull peas
- Shell, sort, and wash the peas.
- If hot packing, cover peas with water, bring to a rolling boil, and skim foam. Drain. Keep the peas hot.
- Pack peas loosely into hot jars at the fill levels in the table above.
- Add salt if you want it.
- Cover with boiling water (raw pack) or boiling cooking liquid (hot pack), leaving 1 inch of headspace.
- Remove air bubbles. Recheck headspace. Wipe rims with a clean damp cloth.
- Apply lids and rings fingertip-tight.
- Load jars onto the canner rack. Fasten the lid.
- Vent steam in a steady stream for 10 minutes before putting on the weight or closing the petcock. Skipping the vent leaves air in the canner and can underprocess the food.
- Bring the canner to the pressure for your altitude (tables below). Start the timer only when that pressure is reached.
- Maintain pressure for the full time. If pressure drops, bring it back up and restart the timer.
- When time is up, turn off the heat. Let the canner depressurize naturally to zero. Do not jiggle the weight or run cold water over the canner. Forced cooling causes siphoning and seal failures.
- Wait 10 minutes more after the gauge reads zero, then open the lid away from your face.
- Lift jars straight up onto a towel. Leave them undisturbed for 12–24 hours.
Process time and pressure
For fresh purple hull, blackeye, crowder, or field peas:
Time (hot or raw pack)
- Pints: 40 minutes
- Quarts: 50 minutes
Dial-gauge canner pressure
| Altitude | Pressure |
|---|---|
| 0–2,000 ft | 11 lb |
| 2,001–4,000 ft | 12 lb |
| 4,001–6,000 ft | 13 lb |
| 6,001–8,000 ft | 14 lb |
Weighted-gauge canner pressure
| Altitude | Pressure |
|---|---|
| 0–1,000 ft | 10 lb |
| Above 1,000 ft | 15 lb |
If you are canning dried purple hull peas that you soaked, use the dried beans or peas schedule instead: after soaking and a 30-minute boil, process pints 75 minutes and quarts 90 minutes at the same pressures.
Look up your town’s elevation once and write it on a card taped to the canner. Using 10 pounds at 2,000 feet on a weighted-gauge canner is a common underprocessing error.
After the jars cool
Press the center of each lid. It should be concave and not flex. Remove the rings, wash the jars, and label with the contents and date.
Store sealed jars in a cool, dark place. Best quality is within a year. The peas are still safe longer if the seal holds and there is no swelling, leakage, spurting liquid, off odor, or mold—but texture and flavor fade.
Unsealed jars go in the refrigerator and should be eaten within a few days, or you can reprocess them the same day with a new lid if the food is still hot and the rim is clean. Reprocessing a second time usually wrecks the texture; refrigeration is often the better save.
Problems that show up in purple hull jars
Dark or purple-brown liquid. Seed-coat anthocyanins bleed into the brine. It is a known trait of blackeye and purple hull peas, not a sign the jar is unsafe by itself. Commercial packers fought this discoloration for decades. At home you cannot fully prevent it. Hot packing and covering the peas completely with liquid help a little.
Foam or scum on top of the peas. Field peas release protein foam when first heated. Hot packing and skimming before you fill jars reduces it. A little foam after processing is common and not, by itself, spoilage.
Mushy peas. Causes include overmature harvest, packing already-soft peas, a long come-up time in an overloaded canner, or using the dried-pea schedule on fresh peas. Start with tender peas and do not pre-cook them past a brief boil.
Jars lose liquid (siphoning). Usually from packing too tight, skipping the 10-minute vent, fluctuating pressure, or cooling the canner too fast. As long as the jar sealed and at least some liquid remains over the food, it is generally considered safe; store it and use those jars first. Peas sitting dry at the top may darken.
Floating peas with a big water gap. Normal with raw pack. The peas sank less because they were packed raw and then expanded. The jar can still be fine if headspace and seal are good.
Cloudy liquid. Can be starch, minerals in hard water, or spoilage. Starch cloud from peas is common. Spoilage cloud usually comes with other signs: unsealed lid, fizzing when opened, sour or unnatural smell. When in doubt, throw the jar out without tasting. Botulism toxin has no reliable home “look or sniff” test.
Canning compared with freezing
Freezing keeps a closer texture to fresh-cooked purple hull peas. NCHFP’s freezing method for blackeye or field peas is straightforward: shell, wash, water-blanch 2 minutes, chill, drain, pack with ½ inch headspace, and freeze.
Can when freezer space is gone, when you want shelf-stable pints for power outages, or when you like the softer, pot-liquor style of canned field peas. Many Southern kitchens do both: freeze the most tender early pickings and can the later, heavier harvest.
Canned peas will not taste like the skillet of fresh purple hulls you ate in July. They will taste like good canned field peas—softer, earthier, ready to season. That is a fair trade if the alternative is letting a bushel go to waste.
How to cook a jar after you open it
Drain or keep the liquid depending on how salty and starchy it is. Most people add the peas and some of their liquid to a saucepan with:
- A smoked ham hock, a strip of bacon, or a spoon of bacon drippings
- Onion
- Black pepper
- A pinch of sugar or a splash of pepper-sauce vinegar at the end
Simmer until the peas are hot and the pork has flavored the pot liquor, usually 15–25 minutes. They are already cooked; you are seasoning, not starting from raw.
Serve with cornbread, sliced onion or chow-chow, and whatever else came out of the same summer garden.
Frequently asked questions
Can I can purple hull peas in a water-bath canner if I add vinegar or lemon juice? No. Adding a little acid does not reliably bring a jar of peas to a safe pH throughout, and there is no tested water-bath recipe for them. Use a pressure canner.
Can I raw-pack frozen purple hull peas? You can thaw them and then follow the fresh-pea directions. Expect some extra softness. Do not put rock-hard frozen peas into jars and hope the process time still applies; the center will heat more slowly.
Do I have to use salt? No. Salt is seasoning only.
Can I mix purple hull peas with snaps, okra, or tomatoes in the same jar? Only if you follow a tested mixed-vegetable recipe and use the process time for the ingredient that needs the longest processing. Random “soup from the garden” jars are not tested.
Why do some websites say 30 minutes for pints? That figure often comes from green English pea charts, or from older or simplified blog posts that treat all “peas” as one food. For southern field peas, extension guidance is 40 minutes for pints and 50 minutes for quarts. Use the longer field-pea time.
Is a dark ring on the inside of the jar lid normal? A thin deposit can form from pigments and minerals. Check the seal and the smell when you open the jar. The ring alone is not a verdict.
How long can I leave unshelled peas before canning? Same day is best. Refrigerate overnight if you must. Do not can peas that smell sour, feel slimy, or have started to ferment in the basket.
Purple hull peas reward a careful pack more than they reward improvisation. Keep the jars loosely filled, the canner fully vented, and the pork for the night you open one. That is the method that matches both the plant and the safety research.