How do I cook 50 kg of red beans in a 500 liter pressure cooker?

The makers also do not publish a dry bean capacity in kilograms or pounds for any of those picks, so there is no published figure to scale a 50 kg batch from.

What follows is what the makers do state about the cookers this site has compared, and where those published figures stop being useful for a batch that size. Cooking quantities and timings for beans are a recipe matter, not a product specification, so they are given here in cups and minutes rather than in weight.

What the published capacities actually are

The Best Pressure Cookers for Canning and Fast Meals guide compares five cookers, and every capacity figure below is the one the maker publishes. The Presto 01781 is listed at 23 Quarts, the T-fal 22-Quart Aluminum Pressure Canner at 22 Quarts, the Instant Pot Duo at 6 Quarts, the Midea 12-in-1 at 8 Quarts, and the Cosori Pressure Cooker 6QT at 6 Quarts.

Those are stovetop canner and electric multi-cooker sizes. The gap is not a matter of a few quarts: the largest published figure here is 23 Quarts, and the question asks about a vessel roughly two orders of magnitude larger.

Because no maker in the guide publishes a figure in liters, this page does not convert any of these capacities. The published numbers stand as the makers write them, in quarts, and the reader can see for themselves how far they sit from the batch described in the question.

Why dry bean capacity is not a published specification

None of the five makers publishes how many pounds or kilograms of dry red beans their cooker holds. The Presto lists Mason jar capacity as 26 Half-Pints, 20 Pints and 7 Quarts, which is a canning figure for filled jars, not a dry bean figure. The T-fal lists 24 half-pint jars, 16 wide-mouth pint jars, 18 pint jars or 7 quart jars per batch, again for jars.

The electric models describe capacity in servings or in quarts. The Instant Pot Duo states that its 6-quart capacity is suited to up to 6 servings, and the Midea states that its 8-quart capacity suits a family of 8. Neither statement is a dry bean weight, and neither can be turned into one without a measurement this site has not made.

This matters for the question as asked. Scaling a 50 kg batch down to a home cooker would require a published dry bean capacity, and there is none. The absence is precise: the makers publish jar counts, quart sizes and serving counts, and they do not publish a dry bean weight for any of these five models.

Fill limits and why they cap a batch

Pressure cookers are filled to a limit rather than to the brim, because beans and other foods expand and foam as they cook. The makers in this guide do not publish a numeric fill line in the fact sheet this site holds, so this page does not state one. What the guide does publish is the overall vessel size, and that size sets the ceiling on any batch.

For the electric models, the published sizes are 6 Quarts for the Instant Pot Duo and the Cosori, and 8 Quarts for the Midea. For the stovetop canners, they are 22 Quarts for the T-fal and 23 Quarts for the Presto. A batch of beans has to fit inside whichever of those vessels is used, with room left for expansion, and the maker’s own instruction book is where the fill rule for that model is set out.

The Presto entry notes that it includes a complete 76-page instruction and recipe book, and the T-fal entry notes a complete step-by-step canning guide. Those documents, not this page, carry the operating limits for each model. This site has not used any of these cookers and does not restate their manuals as if it had.

Heat source and vessel construction

The two stovetop canners are built for a range. The Presto 01781 is described as warp-resistant heavy-gauge aluminum and is stated to work on regular and smooth-top ranges. The T-fal is described as aluminum construction and is stated to be compatible with gas and electric coil cooktops. Those statements describe the base and the cooktop match, not the volume of food the vessel will take.

The three electric models carry their own published electrical figures. The Instant Pot Duo is stated at 1000 watts, 120 V 60 Hz, UL and ULC Listed. The Midea and Cosori entries in the fact sheet do not publish a wattage, so this page does not give one for them.

The Presto entry states fast, even heating from its aluminum body, and the Midea entry states that its stainless steel inner pot is intended to cook food evenly. Those are maker claims about the vessel, and neither is a statement about how a 50 kg load would behave.

Safety systems the makers publish

Each maker lists safety features, and those lists are the place to look for what a cooker does under pressure. The Instant Pot Duo entry states over 10 safety mechanisms, including overheat protection and an easy seal safety lid lock. The Midea entry states a REALSAFE SYSTEM with pressure limit, over temperature and overpressure automatic release. The Cosori entry states 12 safety features, including a double-layer anti-scalding lid and overheat protection.

The stovetop canners approach it differently. The Presto entry states a deluxe pressure dial gauge that registers the complete range of processing pressures, and notes that this precise measurement matters at higher altitudes. The T-fal entry states a secure locking lid, a steam release valve and an easy-to-read gauge.

They describe home canners and electric multi-cookers, and the safety case for a batch of the size in the question would rest on equipment and instructions this site has not compared.

What to do instead

For a home batch, the practical route is to pick one of the cookers in the guide, follow its own instruction book for beans, and work in cups rather than in weight, since the makers publish no dry bean weight.

The right source is the manufacturer of that vessel and its published operating instructions, including its fill limit, its pressure rating and its venting arrangement.