Rabbi Lebowitz, Listening to your 10 minute halacha on whipped cream I have questions about how you poskin. I’ll accept for argument’s sake all the strictest rulings regarding ice/water changes, but whipped cream from a can is not a phase change. Matter has 3 typical phases: solid, liquid and gas (excluding some atypical phase states like plasma). Whipped cream from a can is simply a gas injected into a liquid; the kitchen equivalent is beating egg whites to make a meringue. The gas is still gas and the cream (the ikar) is still a liquid albeit it with different viscosity and density. Since you are going from a liquid to a liquid there is no phase change and thus no nolad. Following your logic, opening a bottle of coke would not be allowed. Here the dissolved carbon dioxide which is not visible as a gas actually forms bubbles when the bottle is opened and the pressure is reduced. This too would seem to be nolad based on your reasoning; nowhere is opening a coke (for this reason) prohibited. I am not a food chemist or an expert in halacha so I would appreciate your thoughts. Larry Adler

Rabbi Lebowitz, Listening to your 10 minute halacha on whipped cream I have questions about how you poskin. I’ll accept for argument’s sake all the strictest rulings regarding ice/water changes, but whipped cream from a can is not a phase change. Matter has 3 typical phases: solid, liquid and gas (excluding some atypical phase states like plasma). Whipped cream from a can is simply a gas injected into a liquid; the kitchen equivalent is beating egg whites to make a meringue. The gas is still gas and the cream (the ikar) is still a liquid albeit it with different viscosity and density. Since you are going from a liquid to a liquid there is no phase change and thus no molad. Following your logic, opening a bottle of coke would not be allowed. Here the dissolved carbon dioxide which is not visible as a gas actually forms bubbles when the bottle is opened and the pressure is reduced. This too would seem to be molad based on your reasoning; nowhere is opening a coke (for this reason) prohibited. I am not a food chemist or an expert in halacha so I would appreciate your thoughts. Larry Adler

<p>While I do understand the&nbsp;science of the "change" in whipped cream, the halacha is not necessarily determined by the three categories of matter. It is likely determined by a percieved change. So, yes whipped cream is just a liquid with air, but it looks and feels like a solid. That <em>may</em> be enough to constitute a change in halacha. That is certainly the opinion of Rav Belsky (posek for the OU and somebody who certainly understands the science). The discussion in the poskim whether the change is sufficient to constitute nolad may depend on this very issue: is the halacha determined by perception or by scientific reality?</p>