I have been making all grain lately but it is hard to set aside a chunk of time to do it all at once. I was wondering if after the wort is in the boil kettle can I leave it and come back for the boil. Of course I'd put the top on the kettle to prevent insects but its feb in ny so fruit flies etc are at a minimum. Basically I'm wondering if there is any issue leaving the wort and coming back to it. If no issue how long can it sit, 1 day, 2, a week?