Would I be able to mash thinner than 2qt/lb of grain if I use beta amylase/starch converter? From what I understand you want a thicker mash so the enzymes will have a greater opportunity to come in contact with starches, but if I add then enzyme can I go thinner? The reason I want to mash thinner is so I don't have to use as much sparge water since I will run off in to a keggle and have my heated sparge water in a 7.5 gallon pot. It's a ten gallon batch with a grain bill of almost 50 lbs. Any help is greatly appeciated. Cheers!
BIAB brewers can get away with adding their whole preboil volume into their mash tun if they want to. I'm not sure what the ramifications would be, but it still makes good beer. On a side note, there's no shame in taking a stock pot from the kitchen and placing it on the stove to get your full amount of sparge water.
I seem to recall there being some great research on this very topic, and the ratio generally had little impact on efficiency unless it was too low (like 1qt/#). Maybe @VikeMan or @Homebrew42 can recall.
You should be fine. If you are really concerned, you could mash longer. I suspect additional enzymes are unnecessary, but perhaps not unhelpful.
I know Kai looked at water to grain ratio's effect on attenuability, but I'm not sure I've read any studies about it's effect on mash efficiency. It may be (I don't know) that there's little impact on conversion efficiency, but if you batch sparge, the original water to grain ratio will have an impact on mash efficiency (i.e. the amount of sugars you actually get out of the mash tun, not he amount of starches converted). It's because of the way the sugar concentrations in the first and second runnings trade off against each other.
I don't believe a simple answer will do justice to your question. The efficiency and fermentability of your wort is dependent on temp, thickness, ph, diastatic power, etc. - - - all related to each other. Here's a pretty good (long) read on the subject. If you have a scientific bent (and lots more time), here's a more detailed analysis. For my interest, what sort of OG are you expecting with 50 lbs of grain for a 10 gallon batch? Have you run your numbers through a mash calculator? With the quantities you posted I suspect you aren't planning a mash-out. If you are above 2 qt/lb you may not need any sparge water.
German brewers often mash very thin, as it makes the pumping from kettles when doing a decoction easier. I forget the upper limit they use, but I have been around 2.5 qt./ lb with no problems. In Kai's paper linked to above he went up to around 5.5 qt/ lb ( if my conversion is correct).
I usually end up about 1.35qts/lb, single infusion batch sparge.I have went as high as 1.75qts/lb. I tie it together with my temps, lower the temp the thinner my mash. I cannot explain why, I just do it with good results, and results are all that really matter. Normally I mash about 1.5/lb it is only when brewing certain beer styles that I deviate. Or as mentioned, doing a decotion mash.
The results of Kai’s experiment were that a thinner mash results in higher brewhouse efficiency. The thinnest mash in his experiment was 5 liters/kg which translates to 2.4 quarts/lb. by my reckoning. “A significant difference was however found in the efficiency. The brewhouse efficiency of the thick mashes remained almost constant between 58 and 60% over the temperature range of the experiments, but the brewhouse efficiency for the thinner mash showed a strong dependency on the temperature and was always better than the efficiency of the thick mash. That leads to the conclusion that thinner mashes perform better and allow for better extraction of the grain.” Cheers!
I would be careful about inferring anything general from Kai's results about brewhouse or mash or conversion efficiency. He does not decribe his sparge technique/calculations (volume) in detail, but does mention topping off with RO water (when necessary) after boiling, which implies varying amounts of total pre-boil water. (Possibly constant sparge volume, plus variable mash volume.) This will not give an accurate measure of mash efficiency in real world terms, where the total water used in the mash and sparge would be equal for a given grist.
This was my general feeling as well, that this is pre-sparge efficiency. I have always (guessed) that a thicker mash will get you a better efficiency due to a higher volume sparge (assuming fly sparging, although possibly also with batch sparging).
Your right Jack, my coffe had not kicked in. I had done the pint is a pound and forgot to get back to quarts.
