"The kitchen department should be very clean and things should not be wasted. This is the first consideration." Srila Prabhupada Letter to Aksayananda, 01-06-76

When preparing food for offering to Lord Krsna, cleanliness is a most important principle. Nothing impure should be offered to the Lord, so the kitchen environment and all gear and utensils must be kept very clean. Foodstuffs being prepared for offering must be used only for that purpose:

"That which is meant to be offered in yajna cannot be tasted by anyone before being offered to the Deity. In our temples, this regulation is in effect. One cannot eat food from the kitchen unless it is offered to the Deity. If something is taken before being offered to the Deity, the entire preparation is polluted and can no longer be offered. Those engaged in Deity worship must know this very well so that they may be saved from committing offenses in Deity worship."

Srimad-Bhagavatam 9:6:8

Srila Prabhupada also instructed that prasadam should never be taken in the kitchen where cooking is going on. If space is limited, part of the kitchen may be partitioned off as a prasadam taking area, but this activity must be done separately from the cooking area.

"One should never eat within the kitchen, there is ample place to eat so why should one eat in the kitchen? Kitchen should be considered as good as the Lord's room, and nobody should wear shoes in the kitchen, smelling and tasting of foods being prepared for the Lord should never be done, talking within the kitchen should be only what is necessary for preparing the prasadam, or about the Lord, and dirty dishes (those taken from kitchen and eaten from) should not be brought back into the kitchen (but if there is no other place to wash them, then they should be put into sink and washed immediately.), hands should always be washed when preparing prasadam, and in this way, everything shall be prepared very cleanly and pure.)"

Srila Prabhupada Letter to Aniruddha, 06-16-68

"It is advisable that food being offered to the Deity be covered when taken from the kitchen to the Deity room. In that way, others may not see it. Those who are not accustomed to following the advanced regulative devotional principles may desire to eat the food, and that is an offense. Therefore no one should be given a chance to even see it. However, when it is brought before the Deity, it must be uncovered."

Caitanya-caritamrta, Madhya lila 4:124

At all times, animals must be kept out of the kitchen area, and away from foodstuffs being prepared. Animals may not be permitted to see foodstuffs as they're being prepared or carried to the altar.

Whenever possible, it is best to have completely separate cooking facilities: a Deity kitchen, and a devotee kitchen. Of course, it is especially difficult for many householders to arrange separate kitchen spaces. At the least, one should maintain cooking pots, utensils, etc. that are only use when cooking for the Lord. Serving spoons must be kept only for Krsna's use, so that foodstuffs are not contaminated while being placed onto the serving dishes.

"Formerly it was the custom of brahmanas to worship Lord Visnu daily at home and cook food in new pots. This system is still going on in Jagannatha Puri. The food would be cooked in earthen pots, all fresh and new, and after cooking, the pots would be thrown away. By the side of the house there was generally a big pit where such pots were thrown."

Caitanya-caritamrta, Adi lila 14:7

Pusta Krsna: "I remember when I first went to Vrndavana and I saw in the villages how they were using dirt and charcoal to clean their pots and pans...
Prabhupada: Yes, they use it.
Pusta Krsna: I thought the.... It was my condition.... I have never seen before. I thought, "What is this? They are making their pots and pans dirty?" Because, you know, we're so accustomed to detergents and soaps, and you have to have so many things to clean.
Prabhupada: That is not also properly clean.
Pusta Krsna: No.
Prabhupada: The down side of the pan remains black. But if you take some dirt and rub it nicely, it become glisten.
Hari-sauri: Dirt is very first-class for cleaning.
Prabhupada: Utensils for cooking purpose must be very, very clean. The.... If the black portion remains, in India they will not touch.
Pusta Krsna: Even on the bottom?
Prabhupada: Yes.
Pusta Krsna: On the outside?
Prabhupada: They'll not touch: "Oh, it is still dirty." But our going on. What can be done? Where there is no cleanliness, little rubbed with soap, that is sufficient. What can be done? But that is not cleanliness. If there is a black spot on the..., it has to.... It will immediately be cleaned. My mother used to see every utensil, whether there is any spot. The maidservant had to surrender. Examine. Then it is no spot. Then it is finished. Otherwise she has to do again. Everything should be neat and clean. The kitchen should be very neat and clean, washed twice daily, opened nicely and smeared with water and gobar. And if you see the kitchen, immediately you'll feel comfortable. It is very cleanly prepared, then offered to the Deity. Then you take. Automatically your mind becomes cleansed."

Srila Prabhupada Room Conversation, 04-22-76, Melbourne

Mahamsa: "Yes, these people are the head of the Marwari community. They don't know how to live. They live in these slums which we saw today. They live all around that area. They are karor-patis.(?)They have crores of rupees.
Prabhupada: To live very gorgeously is not good.
Mahamsa: But even their houses are not so clean, shabby.
Prabhupada: Even though they're not... You cannot say not... They are clean. I have seen in Bombay even the poorest man, his house, and a Parsee gentleman, his house. Kitchen habits. A Parsee's kitchen is so nasty. And here you see this poor man's house, they are neat. Their utensils how much cleansed. I had been in Parsee kitchen. All the pots black. Nothing is cleansed. For eating they use this China. So clean or unclean cannot be understood. Simply washed. But so far the kitchen pots, all are... In our also, when it is handled by this European, American devotees, the black. Down, it is black. That should not be black. It must be cleansed.
Mahamsa: By the heat with these wood, it brings up a lot of soot.
Prabhupada: But it must be cleansed daily.
Mahamsa: It should not come on your finger if you touch it. That black thing.
Prabhupada: Not even you cannot see black, any black spots. Then it is clean. Otherwise not clean. If there's a single black spot, it is not clean. You can see from this poor class of men, how their utensils are cleansed. Before taking water the jug, the waterpot... You'll like to drink water. In our school days there were sweeper, they were a different quarter. So you like to sit down. So clean. The sweeper, cleansing the toilet, bangi. But when you come to his house, living quarter, oh, it is so clean. The bed, the room, the utensils. And they also will take twice, thrice bath, then they will eat. That is a Hindu culture. Even the sweeper class, lowest class. And I have seen one sweeper class who were in Allahabad, regularly worshiping Deity. Very nice worship.
Mahamsa: So a Vaisnava then...
Prabhupada: They took initiation from the Vrndavana Goswami and they follow strictly rules and regulations. Cleanliness is very essential. In English also it is said cleanliness is next to Godliness. Everything should be, especially temple. It will attract them. And we are singing daily, sri-vigraharadhana-nitya-nana-srngara-tan-mandira-marjanadau. Tat-mandira-marjana. Marjana means cleanliness. And want of cleanliness means laziness. If you are lazy you cannot keep clean. "Ah, let me sleep for the time being." That is mode of ignorance. Tamo-guna. So we have to conquer over rajo-guna, tamo-guna. Tada rajas-tamo-bhavah."

Srila Prabhupada Room Conversation, 08-24-76, Hyderbad

Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.