BYK-1681 is a silicone-free defoamer with substrate-wetting properties designed to reduce the air void content and enhance the penetration depth of high-alkaline building material formulations into the substrate. It significantly decreases the air void content in mineral-bound formulations and reduces dynamic surface tension, improving substrate wetting. In concrete additives, particularly those based on PCE formulations, BYK-1681 can effectively reduce or even prevent foam formation.