Short answer. Yes, unless you agreed otherwise. Article 1976 of the Civil Code allows a depositary to commingle grain or other articles of the same kind and quality. When this happens, you do not lose your grain — instead, you acquire a proportionate interest in the combined mass.
What the law says
the depositary may commingle grain or other articles of the same kind and quality, in which case the various depositors shall own or have a proportionate interest in the mass
Civil Code, Article 1976 — Commingling of Fungibles. Read the full provision →
The default rule: commingling is allowed
Article 1976 sets the default position: unless there is a stipulation to the contrary, the depositary may commingle grain or other articles of the same kind and quality. This makes practical sense for warehouses and grain elevators that handle large volumes of identical commodities. Keeping every client's grain in a separate silo would be operationally impossible. The law permits mixing precisely because fungible goods — grain, rice, sugar, oil — are interchangeable by their nature. One bag of the same-quality rice is worth the same as any other.
What happens to your ownership
Your grain does not disappear into the pool. Instead, you become a co-owner with a proportionate interest in the mass. If you deposited 100 sacks and the total combined stock is 1,000 sacks of the same kind and quality, you own 10% of that mass. When you come to withdraw, you are entitled to 100 sacks of equivalent quality — not the exact physical sacks you originally deposited, because those are fungible and no longer separately identifiable. The warehouse's duty is to have the mass available and to deliver your proportionate share on demand.
How to prevent mixing if you want your grain kept separate
The law gives you a clear exit: unless there is a stipulation to the contrary. If keeping your specific grain separate matters to you — for example, if it has a distinct provenance or certification that would be lost in a mixed pool — you need to put that requirement into the deposit agreement. Get it in writing before you deliver the goods. A verbal understanding is hard to prove after the fact, and once mixing has occurred, the law treats the combined mass as jointly owned. The time to insist on separation is before the deposit, not after.
What this means if the warehouse loses part of the stock
Co-ownership in a mass also means co-ownership in any loss. If the warehouse stores 1,000 sacks on behalf of ten clients and 100 sacks are destroyed by fire, each client bears a proportionate share of that loss — assuming the warehouse itself was not negligent. This is a consequence of the commingling arrangement. A warehouse that was negligent in protecting the stock cannot hide behind the proportionate-loss rule; its own liability for the loss remains separate. But among depositors, loss from the mass is shared in proportion to each depositor's share.