My two main questions in contemplating moving to batch sparging to save time over fly sparging are:
- when starting off with batch sparging, is there a general "guestimate" to an efficiency you can expect compared to your fly-sparging efficiency?
- when batch sparging, how quickly/slowly should you drain the wort from the mash/lauter tun into the kettle?
Thanks in advance for the help.
You should probably figure on about the same efficiency as fly sparging. I’ve actually heard from people whose efficiency has improved when moving from fly sparging to batch sparging. That’s usually due to the fact that their lautering system was not designed for even wort flow in fly sparging. Because batch sparging drains sugar from the mash, as opposed to rinsing them out as in fly sparging, batch sparging removes lauter design as a factor. But in general, with a well designed batch sparge system (little to no dead space to leave wort behind) and proper techniques, there’s no reason for a batch sparge system to not be comparable to a fly sparge system in terms of efficiency. These days, after fine tuning my equipment and technique, I average about 85% efficiency for most batch sparged beers.
You can drain the wort as fast as your system will allow without a stuck runoff. Again, since fly sparging relies on rinsing the grain, you want to go slowly to make sure there is no channeling and that you rinse the grain effectively. When you batch sparge, you stir in the sparge water before runoff, which get the sugars into solution in the liquid. This allows you to simply drain them out. Although it will differ depending on your own system (and to some degree, recipe), for my system it takes me about 15 minutes from the time I start the mash runoff until the time I end the sparge runoff to collect about 7.5-8 gallonsof wort. That includesvorlaufing the mash runoff, getting it in the kettle, stirring in the sparge water, vorlaufing again, and running off the sparge.