Olentzero
I don’t know if Manischewitz makes it, but somebody does - it is definitely a manufactured product. (We usually buy the brand called Noam Gourmet, but I doubt if this is sold where you shop). Maybe try for Golds Horseraddish (though my wife says it’s not as good as NG).
Your note about the Russian origin of the word Chrain is interesting, but not surprising. Many well known “Jewish” foods are not Jewish at all, but merely happened to get introduced to the American public by the first immigrants to America from that food’s native country - who happened to be Jewish.
Enderw24
I don’t object to your complaining about the price gouging on Passover products, which have a long history. (They are the work of the manufacturers - not the Kosher certifying agencies). What I objected to is your miscategorizing the work of the kosher supervising agencies as a “some rabbi can sneeze in its general direction”. You can ridicule all you want, but in this instance your scorn was based on your own ignorance - specifically, your misimpression - later repeated - that kosher certification has something to do with a Rabbi blessing the food. This has no basis in fact at all. Actually, no sneezing or blessing are done at all in connection with certifying a product as kosher. The sole object of the certification is to attest that the food has no ingredients that would render it unkosher. IOW, a Rabbi certifying the food does not make the food kosher any more than the health department certifying makes makes it healthy, they are merely certifying as to the actual status of the food.
For more info, see the world’s smartest human, as he fights ignorance about this subject in this column, and in this one. Also our worthy C K Dext Havn addressed some Passover issues in this mailbag article.
With regard to your specific questions: I would venture that your cake mix is made of potato starch or matzo meal. Not flour. Hence, the leavening is not an issue.
As for Diet Coke, I believe aspertame is generally made with kitniyos. Halachic opinions differ as to its status on Passover. But I am very surprised that Diet Coke would be selling at 4 times it’s normal price at Passover time. In my area there are special bottles of Coke and Pepsi that are Kosher for Passover (made with sugar and not corn syrup), but they sell for the exact same price as regular Pepsi and Coke.
The cost of the actual certification, spread out among all the many items sold, is negligible. It is, however, a standard canard of Anti-Semites that this added cost is considerable and constitutes a secret “Jew Tax” being paid by all the good Gentiles of America to fund the Cabal of the Jewish Elders. Or whatever.
In general, as food technology has become more complex there are more and more items that need kosher certification, because of the numerous ingredients, which themselves have sub-ingredients etc. My parents remember a time when people could buy products without any certification, simply by checking the ingredients, but those days are long gone now.
But again I do agree that there is price gouging associated with Passover foods. This has to do with the limited competition in a very short-duration market. Possibly other factors as well. It is my understanding that the problem has abated somewhat in recent years (among other things, there has been a government crackdown in the NYC area). I don’t know what the cost of the machine made matzo is. I buy the round hand-made stuff, which goes for about $14 a pound. Which is a lot, but the process of making it properly is very expensive. I don’t think it is excessive. I also don’t buy a whole lot.