Rabbi Richter’s 11th grade honors Talmud class scientifically tested the halachic principle that a food’s flavor transfers to the vessel in which it was cooked. The students boiled water in four cast iron skillets: two were brand new and two were previously used.
“We boiled water in all the skillets to create a control,” explained Rabbi Richter. “This let us know what the water would taste like simply by cooking it in this skillet. After that we fried fish in one of the new skillets and in one of the used skillets. Next, we cooked hot peppers in the other new and used skillets. After frying the fish and cooking the peppers, we cleaned all the skillets with soap and cold water and then cooked water in them.”
The students lined up the water from each skillet to test the taste from before and after the items were cooked. Four freshman students who were not part of the experiment tasted the water from before the food was cooked and compared it to the water from the same skillet after the food was cooked.
The results were quite interesting, as Rabbi Richter reported:
“Both students who tasted the water from the new skillet (before anything was cooked in it) reported that the water tasted like regular water (as expected). The student who tasted the water that was cooked in the skillet after fish was fried in it reported that the water still tasted like regular water. However, the student who tasted the water that was cooked after the peppers were cooked in it said that there was clearly a ‘spicy’ taste in the water.
These findings were consistent with what we expected. We know that modern metals are much less absorbent than those of Talmudic times, so it was not a surprise that the fish skillet did not give discernible flavor into the water subsequently cooked in it. However, the finding that the hot peppers did give discernible flavor into the water subsequently cooked there, did prove that there is some flavor absorbed in the pot, but can only recognized with sharp flavors (davar charif).
When it came to the students who were tasting the water (both before and after) from the used skillets, there were different findings. The student who tasted the water from the fish skillet claimed that the water tasted the same before and after. However, the student who tasted the water from the hot pepper skillet claimed that the water from before the peppers tasted like fish, but the water from after the peppers tasted like regular water!
This second finding obviously left us a bit perplexed; why would the water cooked in the original pot have a flavor of fish but the second water, cooked after hot peppers, have no flavor?! There is a possible explanation for the above phenomenon.
The reason why the original water had a taste is because the skillet was previously used and there was flavor absorbed in it from previous cooking. Whether it actually tasted like fish or just another flavor can be debated (we couldn't ask another student to taste it, since the first student drank from the cup and we are very germ conscious now), but it stands to reason that there would be some flavor expelled from the pot into the water.
The reason why the second water cooked in that skillet had no flavor may have been because the second time we cooked the water, we were rushed (since the bell rang) and we didn't allow it to cook long enough to absorb the flavor of the hot pepper absorbed into skillet.
Why did the water no longer taste like fish, you ask? That is because the pot was cleansed through the cooking of water and peppers in it which already caused it to purge all previous flavor from it, otherwise known in halachic terms as hagola.