2x 2.5 gallon mash/boil to create 5 gallon batch?

I can't see why either of the two options wouldn't work. The only real adjustment you might want to consider is hop utilization. By using smaller boiling amounts, your hop utilization will not be the same as it would be with a larger volume. You can probably figure out the difference by using BeerSmith or other brewing software or online programs.

As for using a sous vide stick, I don't have any experience with that, but it might create some hot spots if not moved around constantly. Hopefully others with more experience can comment.

 

I brewed for more than 10 years using a single mash but splitting the mash into halves that boiled separately, on different stove burners. I couldn't get one burner to get a full batch to a boil but I could get two burners to bring half a batch to a boil. It worked fine. Split your hop additions evenly over both boils. At the end, combine, insert immersion chiller, and chill as a single batch.

 

From my limited experience, I can only see two ways to have a problem (not necessarily indicated in your outline).

1- splashing 180F+ wort around, inducing oxidation.
2- having some sort of sanitation problem with the cooled worts prior to getting them into the fermenter, resulting in infection.

Neither seem like they'd be very troublesome to deal with, though.

The closest I've come is doing two mashes to make a 10 gallon batch.

Enjoy!

 

Google Sous Vide and Mash https://www.homebrewersassociation.org/how-to-brew/making-beer-with-a-sous-vide-immersion-cooker/. One thing to keep in mind, you must use a BIAB to keep the grain away from the intake on the sous vide. And it might help if you have something attached to the stick to keep the bag from getting sucked into the vents and restricting flows. After your mash make sure you get the stick out and disassemble it to clean the heating probe. I would not use the sous vide to heat the mash to boil temps, you are asking to cake sugars on the probe and people say that is a bitch to clean. I think it would work well for the mash.

 

I'm pretty sure that your question has come up in the past, and I think the general consensus was that you can split a batch as you propose to do, but this procedure will likely produce a slightly different beer. I think the reason was that the hops will not produce their full bitterness/flavor profile because of the smaller amount of liquid in which they boil (hop utilization). However, I think it was suggested that adding a larger quantity of hops could (would?) overcome this issue.

I don't recall if there were any other issues to add to the above, but here is a list of previous threads that use 'split' in the thread's title that might be of use to you. Some threads don't apply to your question, but maybe some do. https://www.beeradvocate.com/commun...t&t=post&o=date&g=1&c[title_only]=1&c[node]=8

I also did a search without qualifying it to look only at thread titles, but a ton of posts were returned from that search. You can try it to see if you can find something more specific if my link above doesn't give you any help, and do that search using 'split' or 'split batch' or 'split + batch' or 'apartment' or 'utilization' and see what comes up. Or maybe since we bumped this thread to the top someone with more info will chime in.

 

Half the hops in half the volume (1/2 of both the starting and ending volumes), should yield the same IBUs. It's about the ratio of alpha acids to wort.

I think the notion that bigger volumes increase hop utilization comes from these two facts...
- The same amount of hops in two different boil volumes will result in more efficient utilization for the larger volume, because the ratio of alpha acids to wort is different. (Thus higher hop utililization for full boils vs partial boils).
- Pro Brewers tend to get better bittering utilization in their very large boil kettles than we do, assuming the same proportions of hops to wort. But that's due in large part to the fact that it takes a long time to cool these batches down, so the hops contact time with the hot wort is extended.

 

See here:

https://www.facebook.com/media/set/?set=a.10211128629362461.1073741836.1558683681&type=3

Cooler mash tun not required. Usually I BIAB. Split boil stovetop works just fine. I've only done it like a dozen dozen times.

 

I also have equipment limitations that require me to split batches. The numbers that matter to me typically come up fine, or within range. SInce I do batch sparging, one pot is the first runnings, the second is the second runnings. So, the limitation actually also gives me the option to make two completely different beers as well.
I chill them separately. If I'm combining them, I can pitch one to get the yeast moving, and come in with the second when that's cooled and ready.
For hops. Sometimes I split them. Sometimes not. I'm more concerned with using the hop flavors, and aromatics, and not so much the blasting those into submission and utilizing them for bitterness. Be careful about what you wish for in maximizing your hop utilization. It's not always helpful, and there is definitely a point where it is too much for its own good.

You can also look into liquoring back your beer post boil if you want to make a larger volume beer than what you have capacity for as well. i.e. deliberately brew it to a higher abv, and and bring it down to what you designed it for when you're ready to pitch.
https://www.brewersfriend.com/dilution-and-boiloff-gravity-calculator/
Or beersmith also has this in its tools.

 

The only thing you need to adjust is the boiloff rate. On my last 6-gallon batch on the stovetop in 3 kettles (pictured in Facebook), my boiloff rate was exactly 22%. Under normal single-kettle circumstances, it might have been closer to like 17-18%. This is because the extra burners and extra surface area of the boiling wort will cause you to lose more volume to evaporation. So, you'll need to sparge just a little extra or plan to add extra water at the end of the boil to hit your target volume of 6 gallons or whatever. So plan for that. But as for the recipe itself, I don't change a damn thing. Never worried about "hop utilization" or any of that jazz. It turns out great just ignoring any "advice" in that regard. However, I do split my hops about half and half between at least two (of my three) kettles.

Near the end of the boil, the worts are concentrated enough that I try to combine them into just one kettle if I can, or mostly one kettle with a little on the side. For chilling, I'm a bit unconventional.... I don't own a chiller and never will. I chill in a cold water bath in a large tub sink, replacing the bath water every 20-30 minutes over the course of about an hour. People laugh but it friggin works. Assuming you own one chiller, just chill one the normal way and the other half in a tub sink like I do. It works great.

P.S. Sometimes during winter I use snow. See picture below.

Cheers.

 

Looks fine to me.
My only suggestion is do the whirlpool as you are chilling. Personally, I've become a fan of getting the temp below 180 and doing my flame out/whirlpool additions then. You're not going after the flavor compounds at the steeping temps.

 

Your beer should be safe from contamination with what you did in your sanitation program. But. Huh. Get a thief and extract some beer, and sample it while you check your gravity. No harm in that. Probably safer than what you are doing too.
I'd probably think about replacing that hydrometer as well. Just be on the safe side of things and get rid of that one.

 

Did it appear that a beer color was collecting inside the chamber where the lead resides? It's hard to tell anything from your pics. Lead is not like a fine powder and does not easily dissolve during a few minutes contact with a liquid, so I think you're okay. And I think it takes repeated exposures to lead before your body builds up enough of it to begin to cause concern. Children are more easily affected by lead build-up, and you're not giving your beer to kids. Maybe someone who is more into chemistry can counter my logic.

Since your OG was lower than planned because of having too much water in your beer, you can also expect the FG to follow accordingly and be lower than expected too.