Brewing a 1.100 - how to make sure I hit the OG

[skibb]

My buddy just got himself a brew-magic system and we are currently on our 3rd brew and we want to go big.

Right now we are looking at brewing up a 5.5 gallon batch of wheat wine with an OG of 1.092. I have never brewed anything this big before - the grain bill alone is 19 lb (with 1 lb of table sugar to be added during primary, bringing the OG to 1.100). The efficiency is set to 70%. The previous few brews have yielded efficiencies in the 80's (though they were of much lower OGs). The mash tun has more than enough room to fit the grains and water needed (its a converted keg)

I'm just curious how I should go about hitting the desired OG - I would really like to make 5.5 gallons (or more), but I def wouldn't want to make less than 5 gallons. I don't mind sparging with more water and boiling longer - I'm just not sure how to go about calculating that. I do have a refractometer to take quick readings of the run off if needed.

Any help would be greatly appreciated!

 

[Walker]

I'd keep some extract handy. Brew as best you can and check the gravity. If it's low, add the extract to get it back up.

 

[eager_brewer]

I can't remeber where I read the thread here but I brew a lot of beers with SG of 1.110 and can hit it consistantly with no extract. Instead of only sparging with 5 gallons of water I will run off close to 9.5 gallons and then boil it down with an average evaporation rate of .9 gallons an hour. Yes it takes about 4+ hour boild but that is the perfect time to have a few brews. But like Walker said keep some extract on hand just in case. I also take gravity readings during the boil to make sure I am doing well.

 

[Yankeehillbrewer]

I double batch-sparge and on my big brews I will not only use more sparge water, but I also run off my sparge slower. It has really helped me hit my numbers on the big beers. Are you batch sparging or fly sparging?

 

[devilishprune]

I double batch-sparge and on my big brews I will not only use more sparge water, but I also run off my sparge slower. It has really helped me hit my numbers on the big beers. Are you batch sparging or fly sparging?

But really that doesn't even matter, because your boil off rate isn't going to change. Just up your sparge amount by whatever percent longer you are going to boil. If you normally boil 60mins and you want to boil for 90, just up your sparge amount by 50%. That's how I do it anyway.

That doesn't really work all the time, but there are a select few scenarios where it would.

If you boil off 1 gallon per hour, and you get 3 gallons of runnings from your mash and sparge with 3 gallons. If you wanted to do a 90 minute boil then you would boil 1.5 gallons off rather than 1, and if you sparged with 50% more water then you would have 7.5 gallons in the kettle, and thus 6 gallons in the fermenter.

If you sparged with a really small amount of water then this might work.

 

[Yankeehillbrewer]

That doesn't really work all the time, but there are a select few scenarios where it would.

If you boil off 1 gallon per hour, and you get 3 gallons of runnings from your mash and sparge with 3 gallons. If you wanted to do a 90 minute boil then you would boil 1.5 gallons off rather than 1, and if you sparged with 50% more water then you would have 7.5 gallons in the kettle, and thus 6 gallons in the fermenter.

If you sparged with a really small amount of water then this might work.

yeah, I typed that all f'd up, not at all what i meant to say. I meant to say sparge enough to gather 50% more of your boil off rate.