I was wondering if there is a general rule of thumb on how to estimate your OG with second runnings. I get 75% efficiency with first runnings and was wondering if there was an easy way to figure this out. I know it would not be exact, but maybe I could assume that if I get 75% efficiency with first runnings, then I would get 20% efficiency with second runnings? Can anyone help me out with this?
Here's a table - http://www.brewingtechniques.com/library/backissues/issue2.2/moshertable.html Here's a calculator - http://www.astrocaver.com/java/Parti-Gyle.html
I mash at 1.5 quarts per pound, and that gives me 60% efficiency. I then sparge with another quart per pound and get another 20% efficiency. Usually this just means that I'll get 5 gallons of beer at 80% efficiency, but with exceptionally huge beers, that means I get a barleywine at 60% efficiency and a small pale ale at 20% efficiency. The best way to figure out what you can expect is to actually see what you get with your system and process. Take some measurements and see what you get.
75% eff with first runnings? That seems implausible. Is this just a mash in and drain? At what water to grain ratio? I do 1.25qt/# and get 59% and 75-80% overall.
Do you batch sparge? I do 1.25qt/lb and fly sparge. When I am done sparging, I get around 75% efficiency. I don't drain it all the way until the very end, so my first runnings are around 75%. Does this make sense, or am I not explaining it right? Anyway, the reason for the original post is that I am making a quad in a week, and I was going to add more sparge water and just let it keep on going so that I could brew a much smaller beer with the same grainbill. I just wanted to know how to predict what my OG will be if I did this.
I'll vouch for your Mosier (top link) being very accurate. I did a Belgian split and it worked out perfect! Another piece of advice that Gordon Strong suggests, and I found to work with my beer, is that you should add some specialty grain into your second runnings. It takes away some of the grainyness and helps diversity the second beer. A second yeast strain can also be used to help mix it up.
I'm switching to AG this weekend. For a brand new mash tun set up, do I just have to run a batch and determine what my efficiency is after the fact? Maybe I should have take a picture but I'm using a 10 gal. round Igloo cooler with a loop of copper pipe with slits from a Dremel in the bottom of the pipe every inch or so. 5 gal. batches. 70% a good estimate to start with?
Yes I do, as a matter of fact. I would not describe this as first runnings. To me first runnings are what you get by simply draining your tun fully and not sparging at all. Generally with big beers, you need more sparge water to get the same efficiency. I would build a grain bill based on 60% for the quad, and expect 20% for the small beer. I get ~75% efficiency, unless I sparge with lots of water compared to the grain, and then I can get upwards of 85%. Those 10 extra points aren't worth the added boil off unless I am making a second beer or a low gravity beer.
Noob question here-- When collecting second runnings (both first and second runnings would be collected via batch sparge... no fly sparge capacity with my geat at this point), is it necessary to mash the grains for a second hour-long sach. rest? Like... mash tun for 60min, batch sparge for big beer, re-mash for 60min, batch sparge for small beer...? Or just sparge once for big beer, add water, sparge again for small beer?
