Boiling for hours vs using DME..

[Rob2010SS]

Planning my next imperial stout and I'm in a predicament... I wanted a big one, was targeting 1.130 on the OG for a post boil volume of 8 gallons. My efficiency really goes in the tank on these big beers so planning for 65% efficiency out of the mash which may even still be too high but for conversation sake, you'll get where I'm going.

8 gallons post boil with an OG of 1.130, my recipe is at 49.75 lbs of grain.
At 1.2 qts/lb of grain, I'm at 15 gallons strike volume.
I anticipate that the 49.75 lbs of grain will absorb 5.5 gallons.
This leaves me with 9.5 gallons coming out of the mash.

Ideally, in any other beer, I'd only want 8.75 gallons pre-boil to end up with 8 gallons post boil.

This 9.5 gallons is before sparging. So if I sparged on top of that, I'd end up with a TON of volume and would have to boil that off. Not a fan of that option....


My other option, in my opinion, is to target a smaller OG - say 1.080-1.090. I'll get better efficiency and therefore won't run into the problem above. Then I would just have to use DME to get up to my preferred OG.

My question to you: What are the pros and cons of doing this? Should I be using a particular type of DME other than Golden Light?

 

[BrewnWKopperKat]

Which type of DME to use?

Back in 2015, there was an article at the Briess blog (still available in the Internet Archvies [link]) which mentions the base malt used with each type of DME:

• CBW® Pilsen Light malt extract : 99% Briess Pilsen Malt 1% Briess Carapils® Malt
• CBW® Golden Light Malt: Briess Brewers Malt, and 1% Briess Carapils® Malt
• CBW® Pale Ale malt extract: 100% Briess Pale Ale Malt

eta: most of this information is also available here: LME & DME - Briess Brewer's Grade Malt Extracts

 

[Sammy86]

My question to you: What are the pros and cons of doing this? Should I be using a particular type of DME other than Golden Light?

Pros: less grain, better efficiency and depending on what you get out of the mash you can add exactly the amount of DME needed to reach your gravity.

Cons: I don't see any.

 

[Rob2010SS]

Ran through the numbers with some different factors put in. Appears that I have to stay around 1.100 to be able to still sparge and not have to boil forever. I think I may still end up having to grab a little extra wort and extend my boil time but not too long...

I'll plan the recipe for 1.100 OG and use DME to get it up to 1.120. Hopefully that gets me where I want!

 

[IslandLizard]

You can always boil down just your runnings from the sparge, so you don't have to boil the whole batch for hours.

Or do a reiterated mash, splitting the mash in half, using the wort from the first sparge (2nd runnings) as the strike water for your 2nd mash.

In either process, batch sparging is the better method over fly sparging.

 

[dwhite60]

I'd add some dme rather than boiling for hours. In a beer that big you most likely won't notice the difference.

 

[madscientist451]

I think you should go ahead and brew it and see what your first runnings gravity is. Skip the sparge, (make a small beer when you are done) and have some DME on hand in case you need to add it at the end of the boil.
I plugged your numbers into this calculator and I think you'll be pretty close:
https://pricelessbrewing.github.io/BiabCalc/#Advanced

 

[Cloud Surfer]

I do reiterated mashes for my big Imperial Stouts and Barley Wines, and it’s a process that works well to get reasonable efficiency without having to boil forever. Though I do 90-120 minute boils on my RIS and 180 minute on my Barley Wines to get the flavours I want.

The other option is to reduce the volume of RIS you are making which might remove the requirement for any DME additions.