Proofer and retarder proofer are both designed to the product proofing process. The main difference relies on the fact that a retarder proofer can generate cold air while a proofer cannot. – The retarder proofer can lower the temperature down to +4C in order to stop the proofing process till the proper time. You can also use the retarder proofer as a simple fridge when it is empty. – The lowest temperature in a proofer is the room temperature. The proofer can only warm products up to 38C. Therefore, stopping or slowing down the proofing process in a proofer is quite difficult to do, not to say impossible without damaging the products themselves. Retarder proofers are therefore much more flexible.