Thoughts on doing a second runnings beer. First beer (barleywine), grain bill will be around 22lbs. for a 5.5 gallon batch. Looking at doing a second mash adding a little more two row to create another 5.5 gallon pale ale. Anyone else do a second beer with biab? Thanks
It can be done, but I’d make sure your MLT can hold additional #5. I would suggest grabbing some dme/lme as insurance for both brews.
I do it myself on a regular basis.My last one I had a Rye pale ale in my 52 litre mash tun and was mashing a stout in a fermenter.Once both had finished mashing with no mash out I then combined the two grain bills in the mash tun.
These three have completed primary with the second runnings OG @1.043 and fermented with a Belgian yeast.
Should be interesting for tasting when I transfer them secondary for dry hopping.
Definitely well worth trying as for an extra hour on brew day you have an additional brew.
I save my BIAB second runnings for starters.
The calculator under my signatur line allows you to estimate the strength of your second runnings. You’ll have to adjust the water retention parameter to match your BIAB process.
Assuming typical (ish) boil off rates, no mashtun loss, you should be looking at around 67-70% lauter efficiency (so your remaining grain bed would be approximately ~6.6 lbs of grain), for a no sparge 22lb grain bill with a 0.08 gal/lb grain absorption. If you’re not squeezing, then drop that down to ~63% (~8.15 lbs of grain equivalence remaining).
By using lauter efficiency, and equivalent remaining grain, it’s easy to throw that amount into a new recipe rather than using a gyle calculator and then a blending calculator and then adding additional new recipe to add onto it. Just remember to adjust your water volume, as the remaining equivalent grain will not absorb additional water (unless you squeezed for first runnings, but won’t on this second brew).
Predictions made using my software, which is based on braukaisers model, but much simplified with negligible loss in accuracy 0.02%.
Why would boil-off rate factor into your lauter efficiency?
Boil off rate is a factor for how much total water is being used, which has a direct impact on lauter efficency.
I guess so, although it should be constant. Dead space and absorption are the main players I’d be worried about. Boil off is a passive component in lauter efficiency as opposed to mash losses being active components.
It’s still a factor, although the difference is a matter of 0.5-2% lauter efficiency. Mashtun, kettle losses and absorption rate are definitely the big three.
I thought I had responded, but I guess it didn’t post. Thanks for your input. I am trying it!