My favorite way to requeen a large hive:
I remove the established queen and let the hive sit queenless for about 5-6 days. Let them make all the queen cells they want. Then I drop a
marked virgin queen in the top, direct release right through the hole in the inner cover. The virgin will go through the hive and remove all the started queen cells for me. The hive gets a decent brood break. It is far less labor intensive to to it this way than to introduce a mated queen, where missed started cells can and will be deadly to the new queen. If you miss one started cell, it will continue to grow and upon hatching the virgin will kill your mated queen..IF they accept her to begin with with started cells.
I really dislike a 24 hour queenless period. Causes more trouble that it is worth in my opinion. I introduce caged mated queens with ether no queenless period or at
least a 3 day queenless period. After 3 days started cells are easier to find and remove.
Using queen cells and virgins are crazy easy if they are avaiable to you, you are in an area that is good for mating & if you have time. If you have poor local genetics or it is getting late in the season, a mated queen from a good breeder is a better choice.
I sold several overwintered breeder queens this year out of hives that were 4 & 5 deeps. This was the method I used to requeen and was 100% successful in both accptance of the virgin, the colonies self removal of queen cells and mated returns of the virgin.
I'd already made up far more nucs than I planned because of good overwintering success, so breaking up more hives wasn't something I wanted to do. (Not to mention I was running out of equipment.)
Take a look at my recent tally of colonies:
Yikes! What worries me is, if we have an extended late summer dearth, I'll be feeding these smaller colonies. When making up nucs, That is importaint to consider. In fact I am heading to Costco today to buy another ton of sugar just in case. (I have one ton in storage already) I see sugar prices are climbing fast and I'll be paying $1.00 per bag more than the last ton I bought.
Most of my nucs on standard frames are in 8 frame deeps and made early so they are heavy and strong. Trying to plan ahead so I can feed as little as possible this fall. Every year I am in better shape with resources so I can make nucs stronger, earlier.
The method of using a queen cell or virgin is extremly easy. An since I am faced with too many large hives with 2012 and 2013 queens, it is a method I will be using myself on a large scale. I will be overwintering those older queens in smaller nucs and go into the winter with young queens in the large hives.