Double "concentrated" lager split into two batches - questions?

[Sparger]

Using a grainfather with a 17-18 lb Pilsner grain bill and double the normal amount of hops, I was going to brew a 7 gallon lager and then counterflow chill half to one fermenter and the other half to another fermenter. Was then going to fill both fermenters to a 5.5 gallon level with filtered ice water. I was hoping to a little less than 5 percent alcohol for the two batches. I may also reduce the grain bill by a couple of pounds and just throw in some dextrin at the end of the boil (I like them dry).
Anyone try this before? Is this a recommended strategy for getting two 5.5 gallon batches out of one brewing session? I am concerned that a wort with this much sugar might lead to some darkening and taste changes, even with a 120v electric brew system.

 

[Smellyglove]

Just remember that your efficiency will go down when brewing bigger worts. I'm currently doing this (not on a GF though), and the taste and mouthfeel is different, the whole beer is infact different, it will not be the same as when doing a "single wort" to the correct OG.

 

[Sparger]

Just remember that your efficiency will go down when brewing bigger worts. I'm currently doing this (not on a GF though), and the taste and mouthfeel is different, the whole beer is infact different, it will not be the same as when doing a "single wort" to the correct OG.

Any ideas on the reasons why the taste and mouth feel are changing? Are you using propane/gas? I wonder if 110v GF with the slower heat time would "cook" / caramelize the wort less than a gas system. I'll post the results in few weeks.

 

[Smellyglove]

Any ideas on the reasons why the taste and mouth feel are changing? Are you using propane/gas? I wonder if 110v GF with the slower heat time would "cook" / caramelize the wort less than a gas system. I'll post the results in few weeks.

No I'm using induction and have the (almost) same boil-off rate as normal batches. I boil with a low intensity btw. I feel the body is thinner, haven't tasted very much on the bitterness yet, and it's dryer. So I've upped the water adjustments and started to mash a bit higher, it's a bit closer to the mouthfeel, but still not there, it's quite different (I dissect all my beers tastewise). I prefer the regular beers, but this is just a challenge so I'll keep up doing some tweaking for the high gravity batches.

I dilute with 50% water pre fermentation btw and have always at least used double the salts as my thinking was that I'd need double in the boil since I'm diluting with 50%.

 

[chickypad]

I have a few recipes that I brew that I will sometimes top off like this, in my case I aim for about 3.25 gal post boil with top off in the fermenter to 5.5 gal so more like 40% top off. The recipes I have done this way are indistinguishable from the beers brewed with the full strength recipe, but most of them are mid-ABV beers and nothing with big mouthfeel (a blonde, some wheat beers, and one higher gravity saison but that one has a lot of sugar and is fairly dry baseline).

 

[JohnSand]

When I was brewing stove top in a 20qt pot, I routinely topped off in the pot with sparge, then in the fermenter with water. Some of those brews were very well received, and got good scores at competition. It's really not different than topping off an extract batch, except that you are doing the extracting from grain.

 

[Sparger]

My GF double batch worked fine. 17lbs pilsner, 1lb melanoidin. The trick is to have a lot of sparge water. I got 14 gallons pre-boil. Just kept sparging into another container until I had two 7 pre-boil gallon batches (85 min boils). (Split the first 8 gallons post mash into two 4-gallon batches, then split sparge runoff between the two pre-boil batches. Postboil, my two batches had a 1.05 OG (Czech pilsner) and the German pilsner 1.054 OGs - fermenter volume 5.5 gallons x 2. At the last minute, I just continued to sparge past GF's calculator because the wort was still coming out with some color and sugar and I suspected it would be tastier than just topping up the two batches with plain water.

 

[chickypad]

You just need to be careful about oversparging so you don't get tannins. With the big grainbill you're probably okay, or you could batch sparge the next time. The number people usually target is keeping the end runnings above 1.010. The reason I top off with water is that I don't want to mess with extra pots/containers or doing a second boil. Either way, as long as you hit the same OG I haven't found any impact on taste.

 

[Sparger]

You just need to be careful about oversparging so you don't get tannins. With the big grainbill you're probably okay, or you could batch sparge the next time. The number people usually target is keeping the end runnings above 1.010. The reason I top off with water is that I don't want to mess with extra pots/containers or doing a second boil. Either way, as long as you hit the same OG I haven't found any impact on taste.

Yes - I had a lot of pots going to get all that sparge. If the final beers taste good, I’ll invest in another cheap 5 gallon pot.

 

[Smellyglove]

pH is imo more important than the SG of last runnings. It all depends on the grist.