watering down vs brewing low.

[KyleWolf]

Hey everyone.

I had a question about making a 10 gal batch of fairly low (low 1.040's, upper 1.030s). I don't really have the room to accurately control the temp for two five gal batches at the same time, so I was hoping to keep it in one fermenter.

I thought about doing 5 gals of a 1.070 beer, then doubling the volume with water at kegging. I don't think it is just that easy as to "double the gravity and then double the volume". There are a number of issues that come to mind and I wanted to see what you thought.


body- Since (lets say) that if I did the 5 gal batch, the final gravity sat at 1.010ish. but if I did the 10 gal boil, it would probably finish around 1.007esque. When I double the volume of the 5 gal batch, would the FG after water addition become too low and the body would be lowered to a point where it wasn't proportional? (the gravity might end at 1.000 or even lower, as it would depend on the amount of sugar vs the amount of alcohol)

Hops/IBU- While the body of the beer is my primary concern, I am curious as to how doubling the water at kegging would effect the IBUs and hop flavors of a beer. Lets assume its a pale ale just for a reference. I understand the high gravity initially would restrict hop utilization compared to a 10gal regular batch, but I wonder if it would be a noticeable change.

so really, what do you think the benefits vs downfalls would be of doing a high grav 5 gal batch and watering it down to 10 gal at kegging vs doing a regular 10 gal batch and splitting the fermentation into two fermenters?

Thanks
Kyle

 

[DregAddict]

I agree that your FG would pretty much be cut in half, giving the final 10 gallons much less body. And additionally, your hop utilization will be less in a smaller boil, so when you top off, your IBUs will take a big hit also. Another concern I would have is contamination by adding such a large volume of water(I'm sure you plan to sterilize it, but it's just another step where something can go wrong). And you have to worry about oxidation if the water you add aerated the already fermented beer.

If I were you I would just half the ingredients and make two consecutive batches.

 

[ciphin78]

Oops, I see DregAddict already mentioned the oxygen thing...

While I'm not 100% sure on this but I don't think you can just add water before kegging, period. You will be introducing a lot of oxygen into your beer that would normally be consumed by the yeast. Oxygen + beer as we all know is a bad combination. Oxidation leads to bad flavors. I think you need to find a way to get to your desired volume pre-fermentation.

 

[IffyG]

Listen to the last (I think it's the last) Brewstrong Episode in their high gravity brewing series. Tasty Mcdole does this all the time. I think he specifically mentioned brewing a big pilsner and then diluting it down with pre boiled (no oxygen), carbonated water. The results turn out just fine so long as you plan correctly.

 

[KyleWolf]

Listen to the last (I think it's the last) Brewstrong Episode in their high gravity brewing series. Tasty Mcdole does this all the time. I think he specifically mentioned brewing a big pilsner and then diluting it down with pre boiled (no oxygen), carbonated water. The results turn out just fine so long as you plan correctly.

I knew I had heard about it before, and I thought it could have been that. If I remember right, this is actually how budweiser does their beer. Their original beer is like 1.080 and then they dilute it post fermentation. I wasnt sure if doubling the volume would be too much.

Thanks for the suggestions guys. I will have to contemplate.