Another 1st eBIAB question

[chiefwigms]

So I've read most of the threads on BIAB/1st timer questions. I did a test run w/ my 20g CO Brewing setup and did an automatic pid tune for CraftBeerPi. Spotted a few minor leaks, but overall was pleased and think i'm ready for my first BIAB (I've done several extract).

My question isn't really process, but scaling...

I was looking at this vanilla chocolate stout recipe.

2 questions:
1) The recipe is a BIAB profile w/ a 3 gallon boil size, but the batch size is 5g. I didn't do any calculations on boil off, and when I did extract on propane, my boil off was < 1g for 5g batches (now, I have a 4500W ULWD ripple element, and I'll be doing constant recirculation w/ loc-line). Most of the posts I see use ~ 7 +/- .5 g of water for 5g brews. With the 20g setup my dimensions are as follows:
Kettle Dimensions : 17.75" W x 18.75"H
Bottom of Basket : @ 3.5" from bottom
Center of element (center of triclamp weld) : @ 2" from bottom
3 gallon mark : @ 2.5" from bottom

I asked Tim from CO Brewing (and have read a few posts on the 20g setup on HBT) and most say no problems doing 5g in a 20g pot. Any thoughts? Other scaling issues that I'm not aware of? Coming from extract where everything was in a kit, the priceless calc/beersmith profiles are a little intimidating :smack:

2) I've never really messed w/ water profiles - I got a fancy pH meter, and my water is ~7.2 (my local water company posted readings, but i'm not sure how dated they are - emailed them about it). Ignore for now and just try to get things up and running?

 

[jtratcliff]

cross section is the bug-a-boo for boil off, not depth or total volume... If your 20g pot is appreciably wider than a "regular" kettle, then you may have to worry buy but otherwise, brew on!

Have you seen the priceless BIAB calculator: https://pricelessbrewing.github.io/BiabCalc/#Advanced

It'll estimate your boil-off based on kettle size...

@pricelessbrewing can probably give you more info, since he's done the math...

 

[wilserbrewer]

The recipe calls for a 3G infusion for the mash, NOT a 3G boil

You will need to mash full volume or close to it in your 20g system.

I think you just found a shortcoming of large system vs high gravity small batch.

A high gravity batch typically requires reserving as much sparge water as possible...obviously you can't mash w 3.5 gallons on your system.

 

[chiefwigms]

The recipe calls for a 3G infusion for the mash, NOT a 3G boil

You will need to mash full volume or close to it in your 20g system.

I think you just found a shortcoming of large system vs high gravity small batch.

A high gravity batch typically requires reserving as much sparge water as possible...obviously you can't mash w 3.5 gallons on your system.

So I'm fine with the grain bill on a full volume mash? 60 min mash? (Recipe calls for 40)

 

[chiefwigms]

So I ended up finding a different vanilla milk stout recipe

12 lb United Kingdom - Maris Otter Pale
3 lb Flaked Barley
6 oz American - Caramel / Crystal 60L
8 oz American - Caramel / Crystal 120L
8 oz Belgian - Special B
12 oz United Kingdom - Chocolate
12 oz United Kingdom - Pale Chocolate
8 oz American - Roasted Barley
1 lb Lactose (Milk Sugar)
19.38 lb Total

Hops:
0.75 oz Magnum
1 oz Cascade

Before the boil, I calculated the loss of water through my system @ .5 gallons (using a cheap flowmeter), which goes: Kettle -> Pump -> Trub Filter -> Therminator -> Kettle :


The markings on my kettle might not be accurate (need to double check), but I started w/ 8 gallons (marked) and 7.6 gallons from a cheap flowmeter in the kettle, with a pH of 7.73 (probe has ATC, but it was at 88.16F).

I did a recirculating mash for 70min at around ~150 (I tried to export the graph from CraftbeerPi, but it kept erroring). The temperature was taken from a 1wire sensor at the tee after the therminator - in the future, I'm going to get another probe that goes near the element to get a better reading. Took around 4 min to get all the grains mixed in (crushed at .035" except the flaked barley). And after everything got added in, the temp spiked to 165F then settled around 150. After the mash, the kettle markings were at around 5 gallons (again questionable). At this point, the preboil gravity was 1.066 @ 98.4F (pH 5.63 @ 84.56F).

I let the basket hang for like 36 min to drain (I used a plate to squeeze down the grains).

After the 60 min boil (where I forgot to add lactose), I ended up with ~3.5 gallons in my carboy which is pretty disappointing. OG was 1.090 @ 73F w/ a pH of 5.45 @ 83.5F.

The numbers were pretty close, I'm just disappointed with the final batch size. Using a hop spider + biab basket (CO Brewing systems) + trub filter - there was hardly any trub in the kettle (or the trub filter for that matter).

More Pics:



Overall - BIAB was pretty fun. I kept getting distracted by my wife + inlaws, the quick disconnects on my water line broke seal and sprayed water all over the bathroom (i brew in a condo downtown), and even with the hoist, emptying out the wet grains was a PITA. Pretty excited to brew another one & get batch size fixed.