Huge RIS Questions

[Buhjangles]

I'm brewing a 5g Russian Imperial Stout this weekend with a 24 lb grain bill and a target OG of 1.134, should be around 14-15% ABV when all is said and done. I've never done anything this big before so I have a few questions regarding techniques.

I'm mashing is a 15g converted keg with a false bottom and will fly sparge. I had entered a 1.5 liquor to grist ratio into Brewers Friend and it gave me 9 gallons of strike water with about 1.3 gallons of sparge water.

1. Should I lower the grist ration to something like 1.1 (6.6g mash/ 3.7g sparge) to even out the strike and sparge additions? Or is that too thick?

2. I plan on making a partygyle after I collect what I need for the RIS, will one approach for question one benefit this more? For example, Mashing with 9g and sparging with 1.3g vs. mashing with 6.6g and sparging with 3.7g, it seems to me that in the scenario where I sparge with 1.3g there will be much more sugar left for the little beer, but maybe it all evens out.

3. I had a DFH 90minute clone blow 1.5 gallons through my blowoff tube last month, I have a feeling I should prepare for the same on this one, do the foam inhibitors work well for this? I've only used them in my starters and during my boil so far.

Thanks for taking the time!

 

[MarshmallowBlue]

Be sure to use Yeast nutrient and make sure your aeration is the real deal.

 

[Buhjangles]

How much nutrient are we talking about, 5 tsp for a 5g batch? All at once when pitching or staggered like mead additions?

 

[MarshmallowBlue]

Good question! I did my 3 gallon RIS and added it all up front but my grav was 60 points lower. SNA is okay for mead because during that phase you're still aerating your must intentionally, but in beer aeration in primary isn't good. If you're going to move it to secondary while it's still fermenting and can drive off any oxygen for bulk aging, I'd split it 50/50 once at pitch and once when you move to secondary.

 

[Buhjangles]

That makes sense, thanks for the help.

Do you have any thoughts on my other questions?

 

[user 141939]

Just know that the foam inhibitor has silicon which recently the fda says you should not be using in beer unless said beer is filtered. I did not know that and now i have opted for larger fermentors.


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[dcp27]

1) i'd go as thick as you can (~0.9 is thickest i've done), so that you have some actual sparge water or your efficiency is gunna be junk. i guess since you're doing a partigyle this isn't that much of a problem unless you're set on hitting that predicted OG. big brews like this tend to take a decent hit in efficiency, i.e. if your normal is 75%, prolly like 65% is more likely

2) there will be more sugar left in the smaller sparge scenario

i've made a couple around this size, definitely make sure to pitch a ton and mash fairly low. its big enough you'll have body regardless, you don't want to get stuck too high. be sure to keep the ferment temps pretty low too, these can easily get out of control and wind up way too boozy. what yeast do you plan on using?

also, definitely do not rack something this big to secondary while its fermenting, thats just asking to get stuck. i find bulk aging conditions quicker than bottle aging, so just be sure to rack to something with little headspace if you go that route, otherwise i'd just leave it in the primary for about 4 weeks than package

 

[skydvr74]

Here is a long post. Sorry

Ok let’s do some calculations. I am making some assumptions so adjust as necessary.

Assuming 0.5 gal dead space in your BK and MT you need 5.5 gal wort post-boil and based on your numbers you will have ~ 6.92 gal pre-boil
9 gal (strike water) – 2.88 gal(grain absorption) – 0.5 gal (MT dead space) + 1.3 gal (sparge) = 6.92 gal pre-boil
So to estimate your pre-boil SG
5.5*134 = 737 gravity points/6.92 gal= 1.106 pre-boil SG

For 1.5qt/lb
At 1.5qt/lb ratio the maximum theoretical SG you can achieve is 1.080 for the first runnings. In this case I am ignoring dilution from sparging.
9 gal (strike water) – 2.88 gal(grain absorption) – 0.5 gal (MT dead space) + 1.3 gal (sparge) = 6.92 gal pre-boil
Based on these calculations you will achieve an OG of 1.100
6.92*80/5.5 = 1.100 OG for 5 gal.

At 1.1qt/lb maximum theoretical SG you can achieve is 1.102 for the first runnings
6.58 gal (strike water) – 2.88 gal(grain absorption) – 0.5 gal (MT dead space) = 3.2 gal
3.2 gal*102 = 326 gravity points
Assuming 6.92 gal pre-boil volume you would need to sparge with 3.7 gal and extract the remaining 411 gravity points.
411/3.7 = 1.111 SG which is impossible because gravity only goes down after your first runnings.

Long story short. You need to increase your sparge water and boil time significantly or add DME or sugar to hit your desired numbers. IMO, beers this big could use 1-2 pounds of sugar to dry them out otherwise they will finish too high.

For the foaming issue. With enough head space I have never had a problem with big beers. I typically ferment 5gal in a 7 gal bucket.
Good Luck

 

[brewmeister13]

Just brewed a beer very similar to this. I would suggest adding additional sparge water and boiling longer. When I did mine I didn't have a set sparge amount, but instead stopped sparging when I had the required Sugars to hit OG and then figured my boil time based off of my predicted boil off rate.

I'd also second skydvr's suggestion on adding sugar. I used 2 lbs turbinado and 2 lbs corn sugar and still only got it down to 1.039 (I mashed way to high though, 156, which caused the high finish).

Ferm cap didn't do a damn thing on my brew, but ymmv. If you are worried about silicon you can get Fermcap at instead of s. It is oil based and safe unfiltered, though most say that s will precipitate to the bottom anyway and filtration is a, cover your ass, suggestion.

 

[old_tx_kbb]

FYI - when doing big beers like this, you're not going to get 70% + efficiency. On my RIS brews, I'm lucky to get 60%...most of the time I'm looking at 55%...but that's with 100% all grain. You can always increase your OG with DME before you finish your boil.

My last RIS used 37 lbs of grain and the OG was 1.105 for 5 gallons. It was my 1st brew with my new rig with 15 Gal HLT and MLT and 20 Gal BK. I'm sure I left a lot of sugar in the mash and could have continue sparging to get a higher preboil volume to boil down.

 

[brewmeister13]

FYI - when doing big beers like this, you're not going to get 70% + efficiency. On my RIS brews, I'm lucky to get 60%...most of the time I'm looking at 55%...but that's with 100% all grain. You can always increase your OG with DME before you finish your boil.

While I would suggest underestimating efficiency, 70%+ isn't impossible. It just depends on how long you are willing to boil. I got just over 72%, but I sparged a good amount and boiled for 3 hours. Not everyone is going to want to do that. And if you are planning a parti-gyle brew I wouldn't suggest it, since the sparge will make up your smaller beer.

 

[Buhjangles]

Thank you for all of the great advice!

I'm pitching around 600billion based on the calculator I used. Called for super high gravity WLP099 but all they had was super San Diego WLP090, so I hope that will do the trick.

If not, has anyone ever pitched later into fermentation to help finish things up? I've heard of brewery's using champagne yeast on 20% plus brews on basic brewing radio. Could I pitch some wlp099 later or even champagne if this stalls out high?


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[dcp27]

I've pitched later into fermentation on a few big ones (>15%). champagne isn't gunna do much if anything as there shouldnt be much simple sugars left and it struggles with the more complex ones. 099 will definitely get you lower if it ends up high, you'll want to pitch a starter of that while its krausened to get the most out of it. if you do end up over 1.12 you may need it, but otherwise you should be OK without. it's probably for the best that you got 090 for primary vs 099, its not the greatest for primary

 

[old_tx_kbb]

I've used 099 on a big% RIS. I had originally pitched an OG of 1.140 to a fresh yeast cake of 001. It worked itself down to 1.045 within a week with oxygen aeration and yeast nutrients. I added the 099 and within less than 24 hours it had come down to 1.020.

I immediately racked to secondary and put it in my freezer. At 30 degrees to put my yeast to sleep....left it there for a month and filtered it. Then racked it to my bourbon barrel.

 

[Buhjangles]

I scrapped the partigyle because as you all mentioned my efficiency was closer to 65%, I ran off 4g and started that boiling down in a second kettle. I kept topping up my main kettle to 7.5g from the other little kettle until I got to 1.090, the added 2 lbs of turbinado and got a reading of 1.100. If my math is good this should get me pretty close to my goal.

Thanks to all for the help, once again HBT came through, love this site.


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