Five Gallon Fly Sparge Question?

[helibrewer]

With regard to the thin/thick mash item. Thin mashes have lower fermentability because beta-amylase is a limiting enzyme. There is adequate alpha-amylase in a wide range of dilutions, but beta-amylase activity decreases with even moderate dilutions and since beta-amylase accounts for about a 70% contribution to fermentability, the fermentability decreases as the mash is diluted. Lewis and Young Brewing, 2nd addition address it. A vast majority of professional brewers use a L:G of about 3. That equates to homebrewers as 1.42 qts/lb of grain.

 

[Gytaryst]

As for the mash stirring bit, we discussed that in class and the consensus was that not stirring makes sense in a single vessel MLT. Rakes aren't used in combination vessels, just in dedicated lauter tuns which are very wide and shallow....same with mash mixers, they are only used in dedicated mash tuns.

I never stirred the mash. For single infusion I got my rest temp stabilized and then just let it go 45 min to an hour, (or more - depending). In another thread I was asking about ways to increase efficiency and a couple of guys suggested stirring the mash every 15 to 20 minutes. I tried that the last time I brewed and didn't have any increase in efficiency. What I did note was that my mash temp dropped a lot more due to opening the MLT to stir. I can't directly heat my MLT nor do I have the capability to recirculate. If I don't open the MLT I only lose 3/4 of a degree in 60 minutes. Opening it caused it to drop, plus stirring it cooled it down even more, so I had to add 1.5 qts of boiling water to bring it back up to rest temp. Not the end of the world I suppose - I just thought it caused more problems and more work than it was worth. If I would have seen a significant jump in my efficiency then I probably would have worked that into my routine. As it is I think I'll go back to stirring real good when I dough in and then not worry about it.

 

[MaryB]

I might stir once during winter when temps in the garage are 40 or so. Mash in at 1.5 quarts per pound. Average brew house efficiency is 80%. And that is with a traditional stainless mash kettle(11 gallon batches). If I add an insulated jacket in winter I can probably skip the stirring.

 

[Gytaryst]

I might stir once during winter when temps in the garage are 40 or so. Mash in at 1.5 quarts per pound. Average brew house efficiency is 80%. And that is with a traditional stainless mash kettle(11 gallon batches). If I add an insulated jacket in winter I can probably skip the stirring.

I tried stirring every 20 minutes last weekend. I'm not going to do that anymore. Extra work, extra hassle, and I didn't notice any difference in efficiency. As far as I can tell the only thing I accomplished was causing a bigger drop in mash temp than necessary.