It might be okay, but I personally wouldn't do it. It takes 5 minutes max to mix it up.
Hi, I wouldn't make it that far in advance, but that's just me.
600 cupcakes?! 
Sounds to me like you need to wrangle some friends to help and get an assembly line going.
You can make cake batter in advance and freeze it. Since you're doing cupcakes I would make it several days before and freeze it in those glad/ziplock tupperware containers that are freezer safe. When you want to use it, you can pull it out frozen and use an ice cream scoop to scoop it into your liners. You can bake it without defrosting it but I think the cupcakes come out mis-shapen. So I let the batter thaw in the liners. I don't like thawing the batter first because it's messier to scoop. Scooping frozen is just so clean and easy.
I just did this last week and it worked great! Cake tested great. I highly recommend this.
For buttercream, I do the following for all my batches buttercream even if I don't have a big order looming.
I use the plug technique listed in the sticky.
http://cakecentral.com/cake-decorating-ftopict-588591.html
I make large batches of buttercream. I make as many plugs as the batch will make. I do approximately 1 cup in each plug if I'm using regular size piping bags. If I'm using the icer tip or a large piping bag, I do 2 cups per plug.
Wrap up the plags as shown in the thread, but fold over the open end as well. Then I place them all in a large freezer bag (or 2) and freeze. When I need to ice something I pull out the number of plugs I need about 30 min before I need them. They defrost right on the counter, I drop them in my piping bag and off I go. The best part about the plugs is there is NO mess loading your piping bags. It's awesome!
I hope this will helps.
You can freeze the cupcakes so you don't have to bake them all at once.
You can make cake batter in advance and freeze it. Since you're doing cupcakes I would make it several days before and freeze it in those glad/ziplock tupperware containers that are freezer safe. When you want to use it, you can pull it out frozen and use an ice cream scoop to scoop it into your liners. You can bake it without defrosting it but I think the cupcakes come out mis-shapen. So I let the batter thaw in the liners. I don't like thawing the batter first because it's messier to scoop. Scooping frozen is just so clean and easy.
I just did this last week and it worked great! Cake tested great. I highly recommend this.
For buttercream, I do the following for all my batches buttercream even if I don't have a big order looming.
I use the plug technique listed in the sticky.
http://cakecentral.com/cake-decorating-ftopict-588591.html
I make large batches of buttercream. I make as many plugs as the batch will make. I do approximately 1 cup in each plug if I'm using regular size piping bags. If I'm using the icer tip or a large piping bag, I do 2 cups per plug.
Wrap up the plags as shown in the thread, but fold over the open end as well. Then I place them all in a large freezer bag (or 2) and freeze. When I need to ice something I pull out the number of plugs I need about 30 min before I need them. They defrost right on the counter, I drop them in my piping bag and off I go. The best part about the plugs is there is NO mess loading your piping bags. It's awesome!
I hope this will helps.
I have 18' bags does this method work for the larger bags as well?
You can make cake batter in advance and freeze it. Since you're doing cupcakes I would make it several days before and freeze it in those glad/ziplock tupperware containers that are freezer safe. When you want to use it, you can pull it out frozen and use an ice cream scoop to scoop it into your liners. You can bake it without defrosting it but I think the cupcakes come out mis-shapen. So I let the batter thaw in the liners. I don't like thawing the batter first because it's messier to scoop. Scooping frozen is just so clean and easy.
Good to know! And OP, that's a lot of cupcakes! I understand now, sorry!
Fsinger84,
You absolutely can do this with larger bags. I do it for 16 inch bags using about 2 cups of BC per plug.
Quote by @%username% on %date%
%body%