I let my runoffs for both 1st runnings and second runnings continue until the grain bed runs dry or nearly dry. Would I be better off adding another half gallon or gallon to the strikewater for 1st runnings, and also to the sparge water for 2nd runnings so that I don't actually run the grain dry? I've heard that it's best to keep the grains consistently in some level of solution for the sugars to run freely, so am I pulling out tannins by letting the water level get very low toward the completion of the runnings?
I think you might be confusing batch sparging and fly sparging. For batch, there's no reason not to let the grain bed run 'dry' (it won't really be dry) before sparging.
I had heard that even for batch it wasn't ideal to continue the runoff until it stops. But if I'm good doing what I've been doing, I'll continue with the same approach. Beats having to recalculate water volumes for all my recipes. Thanks.
agree, so old brewing "wisdom" was that brewers always wanted to keep their grain-bed covered with water to prevent exposure to oxygen during the lautering process. That basically has been debunked, with homebrewers like Denny Conn showing people that batch sparging still produces award winning beers even with grains being exposed. So don't be afraid to drain the whole tun and refill. With that said, you may still want to minimize your exposure & mixing after filling the tun back up. The more mixing you do, the more oxygen you're getting in there and the more tannins could leach.
