Irish Coffee Milk Stout non fermentables - ?? SG

[Greatwhite4]

I'm doing an irish coffee milk stout and i am looking for some general feedback. Heres the info, 5 gallon batch, BIAB, 90 min boil. I had a SG of 1.040 before the boil and lactose, after i added the lactose it was 1.048. I had ~8gallons for the boil, boil went well and ended up with ~5.5gallons and 1.068 SG after the sample cooled. I pitched 2l Irish Ale starter and aerated the wort with pure O2. After ~ 2 weeks in the primary i racked onto a coffee mixture I had soaking for 3 days (3/4lb espresso beans, 750ml whiskey, 1 tsp vanilla 1/2 tsp of almond extracts) and left the coffee sack in. At this time i added some rehydrated Safale 04. I left this for a few more days and removed the coffee and checked SG. It was 1.034. I stirred and warmed up the batch for another 2 weeks and today it was 1.032. Doesnt seem to be going anywhere so i racked it to a keg. I made the mistake of not taking an SG before i racked the wort onto the coffee and whiskey so now i'm left wondering, how much of the final gravity is actually non fermentables, lactose, coffee etc? I assumed the whiskey should have diluted it some but imagine the coffee and the lactose are contributing to the high final gravity by as much as .013. Does anyone have any opinions? Any idea what the heck the ABV will be?

 

[peterj]

I don't think coffee will add any gravity points. And from my calculations I'm assuming you added 1.5 pounds of lactose so I would say the lactose is adding 0.011 points to the final gravity because it is completely non-fermentable. The bottle of whiskey probably dropped your SG by about 1 or 2 points, so using an FG of 1.033 to calculate ABV you would get about 4.6% for the beer portion. Factoring in the ABV of the bottle of whiskey you would have about 5.8% ABV in the final product. I use this dilution calculator to figure stuff like this out: http://primerdigital.com/tools/UniDilution.html.

That FG still seems really high though. I think that would only be around 61% attenuation which is pretty low, but depending on your grainbill and fermentation conditions that could be all you're going to get.

Also, steeping coffee in whiskey sounds like an AWESOME idea!! I'm gonna have to try that! Though I might go with just enough whiskey to cover the grounds.

 

[BigFloyd]

Just to eliminate one possible problem - are you using an hydrometer or a refractometer?

With the lactose (one pound), my milk choc stout done in February finished at 1.022

 

[betarhoalphadelta]

Grain bill? I have a milk stout recipe that is phenomenal, but has a much higher proportion of roasted grains than typical milk stout recipes, and then enough lactose / crystal malt to balance it. A FG in the 1.030 range isn't all that out of the ordinary on that beer.

 

[beertroll]

What was your mash temp? WLP-004 generally has pretty poor attenuation in my experience, particularly so with warmer mashes. If you mashed up in the 155-156 range, that could be a contributor.

 

[Greatwhite4]

Thanks for the responses, I use a hydrometer and as for my BIAB mash, i added my grain to 156F which landed me around 151F and after 90min it didn't go below 145F. Heres my profile:

1.05 tbspPH 5.2 Stabilizer (Mash 60.0 mins)
3.01 kgPale Malt (2 Row) US (2.0 SRM)
0.39 kgChocolate Malt (450.0 SRM)
0.35 kgRoasted Barley (300.0 SRM)
0.32 kgMunich Malt - 10L (10.0 SRM)
0.27 kgBarley, Flaked (1.7 SRM)
0.21 kgOats, Flaked (1.0 SRM)
0.21 kgCaramel/Crystal Malt - 80L (80.0 SRM)
0.11 kgVictory Malt (25.0 SRM)
0.45 kgMilk Sugar (Lactose) (0.0 SRM)
9.11 gMagnum [14.00 %] - Boil 60.0 min
1.00 tspIrish Moss (Boil 10.0 mins)
25.87 gGoldings, East Kent [5.00 %] - Boil 10.0 min
2.0 pkgIrish Ale (Wyeast Labs #1084)
1.0 pkg SafAle English Ale (DCL/Fermentis #S-04)

 

[Greatwhite4]

Force carb'd for a week, turned out awesome, could use more vanilla but still good in my books. Makes a fantastic float with vanilla ice cream. Who could complain about coffee, ice cream, whiskey and beer all together.