One long letter came from Puru dasa in Los Angeles.
Puru was concerned about the temple purchasing sour cream that was known to have rennet, an extract from the stomach lining of a calf, in it and another batch, that had gelatin in it. The rationale used was that almost everything in Kali-yuga is contaminated. And Srila Prabhupada had previously allowed the use of white sugar, which is bleached over animal bones. He had also allowed the purchase of milk that had fish-liver oil added.
A further motivation was the very cheap purchase price of five cents per pound. Therefore the GBC, Jayatirtha, had consented to the purchase of the sour cream because the amount of rennet was very small — about 1 cc per 150 gallons or 1/50,000 of an ounce per pint.
Still, despite the seemingly insignificant quantity, some devotees were disturbed by its use, and thus Puru requested a direct statement from Prabhupada to settle the matter. "It seems to me, though I am a fallen, fault-finding rascal, that only Srila Prabhupada can say whether or not this sour cream is offerable to the Deity, and can be used. I certainly do not know. There are valid arguments on both sides, but the only real point is whether or not Krsna is pleased with such offerings, and only His pure devotee can tell us that."
He added as a postscript that the temple has over 400 pounds of it in the refrigerator, and some had reasoned that Prabhupada would not want to see the sour cream wasted. Puru wanted to know if they should use it up, never buy it again, dump it, or continue to use it and not be agitated over its contents.
Prabhupada's reply was short and clear. "Concerning the use of sour cream in the temple, it should be stopped immediately. Nothing should be offered to the Deities which is purchased in the stores. Things produced by the karmis should not be offered to Radha-Krsna. Ice-cream, if you can prepare it, is OK, but not otherwise. Now, you have such a big stock of this sour cream, so sell the stock at any cost. Who is the rascal who has purchased without permission?"
From "Transcendental Diary" by Hari Sauri Prabhu