I'm sure there is a very short answer to this, but we brewed a 10 gallon batch and a different 5 gallon batch of IPA Sunday. As we were cleaning out the mash, we found well over 5 gallons of "wort" after sparging and all. I would assume we could have made a decent sessionable beer out of it? Am I missing something on this? Our only downfall was lack of yeast and maybe another boil kettle. Thoughts?
Short answer is "Yes" . . . long answer is "Parti-gyle Brewing", here are the details: https://byo.com/mead/item/1963-parti-gyle-brewing-techniques Just about every brew day I run off an extra 1+ liter to fuel up a yeast starter (same thing on a smaller scale).
Absolutely. If you had some extra hops lying around, and extra yeast like you were saying, you could've done a second batch from those runnings, assuming the wort wasn't too low gravity. This is also assuming you didn't wait a day or two to clean out your mash tun to find this extra wort. If the runnings were too thin you could end up with hop water in the end, but if the gravity of the wort was high enough it would make for a good session IPA.
I figured as much. It almost seemed to easy, so I was wondering if there was a catch. How long can you save the run off to use as your yeast starter? We use past pitch from Norther Brewer and it is awesome. It's basically canned wort.
You're talking wort here which is always subject to being infected if you delay fermentation. I typically boil long enough to sanitize, then cool and pitch immediately which is fairly quick for a liter or two. I suppose a larger quantity could be chilled and boiled at a later date . . . but that would make me nervous. If you have the time and feel adventuresome, you can can it: http://www.themadfermentationist.com/2014/11/pressure-canning-starter-wort.html
So, similar to my original question; do you need to "re-rest" the grain? We drained a full 5 gallons after sparging the 10 gallon batch. I've read a few things on the parti gyle technique, but don't see a clear answer. Ideally, you can just continue to sparge until you get enough for the 2nd batch. Or, could you just stop sparging and take whatever is left in the grains?
I tend to save off ~4 L of 2nd runnings and put into four mason jars, seal and freeze (leave room for the freezing wort to expand) on brew day then thaw and boil when I need a yeast starter or am feeding some sour dregs. No problems yet.
I'm not exactly sure what you're asking with your second question. ^^^ After you get conversion on your mash you can do whatever you like. You can add malts after your first runnings. If they need to convert, you'll need to wait. If they are already converted, you don't need to wait. just add water, stir, and run. I typically make a barleywine with first runnings, add some RB and crystal, and make a session stout for my second runnings. For the best efficiency, you want the right amount of sparge water for each sparge. No more, no less. Just remember, nothin's free. If you want 2.5 gallons of 1.090 beer and 2.5 gallons of 1.045 You're using the grains to make 5 gallons of 1.065. (See chart below). Your efficiency might be good on the second runnings, but your first runnings efficiency is always bad. http://morebeer.com/brewingtechniques/library/backissues/issue2.2/moshertable.html
Sometimes I have boiled extra liquid in the mash tun to make starter wort. Realistically, it may not be the best use of time, as DME is not all that expensive in the grand scheme of things. It's just a way to feel less wasteful and holier than thou. Also, it adds cosmic beer karma points when you use one batch to feed another, similar in that way to yeast harvesting, but without the expense of a conical fermenter.
