Something's gone wrong, or right, or something...

[ImpendingDisaster]

Howdy.
I hope someone could shed some light on what's been going on with the volumes and OG of my latest brew.

I'm still not used to Brew Smith's volume calculator, and I think my boil-off is really inconsistent, but I'm still getting really high OGs and more than enough beer into the fermenter. My batch for Brew in a Bag Cream Ale today is as follows:
2.5 kg 2 Row 5 lbs 8 oz
.91 kg 6 Row 2 lbs
.45 kg Fl. Rice 1 lb
.45 kg Fl. Corn 1 lb
.45 kg Carafoam 1 lb

I run my grain through my barley crusher twice. I've found that whole grain sometimes doesn't get pulled through with gap set tight, so I use a fairly wide gap the first time and then run it through again with the gap is set relatively tight on an old credit card.

I started with 28 litres of water (29.58 quarts) and mashed for 90 minutes. I forgot to measure the amount into the kettle, but I tend to squeeze the bag pretty hard (I think I lost about half a litre on my previous batch).

My boil was a bit harder than usual today and I noticed there was a lot of evaporation. I added 2 litres of water during the boil.
I dumped the whole lot into the fermenter, trub and all and got 21 litres. I measured the OG of this and it came to 1.058. I then added my starter and this brought the volume to 22 litres.

There should be a lot of clear beer to go into the keg when all is said and done, but perhaps there is a bit too much extra. If I hadn't added the top up water, I would be fine for volume but my OG would be a good bit higher.

I'm wondering where I might make some adjustments to get things just right. The previous batch, a lager, ended up about .005 higher with 4 litres extra into the fermenter.

Should I mash for a shorter period? In Beer Smith, the "Tot Efficiency" setting is at 72 % (I think that is the default, I don't remember playing with it). Should it be set higher and will that adjust the grain bill for future recipes?

I'd be grateful for any advice.

On a lighter note, here is my faithful assistant, Max Mischief, slacking off, snoozing on the parka I used to insulate the mash today.

 

[m1k3]

I tried you recipe in BeerSmith2 using their default BIAB 13 gallon pot equipment. (I presume Brew in a Bag, you say squeeze the bag)

I get 86% efficiency... when adjusting for 5.55 gallons (21L) and OG of 1.058.

Personally, I don't mind a 1.058 starting gravity but if you consistently get 86% efficiency, you should not use the 72% setting.

I mean if you want to better predict you recipe, you can start creeping up that number until you get what you expect.

 

[m1k3]

another thing... I could have calculated you efficiency from your PreBoil gravity and volume. So, I'm not addressing the boil off rate issue. Sure, the wort might be slightly darker or maybe less fermentable if you are boiling really hard... but the main issue you should dial in first is being able to hit a gravity from your BeerSmith recipe.

 

[chickypad]

I would suggest doing a batch or two where you really measure the volumes well. Looks like you are not measuring grain absoption correctly for one thing, there is no way you only lost 1/2 liter with over 10 lbs of grain I don't care how much you squeezed. A typical loss with BIAB is more like 1/3 qt per lb, so you should have lost 3+ liters. The boil off rate should remain fairly constant for a given pot if you try to boil with the same vigor, I would try to get that consistent as well. Once you have the numbers dialed in you should be able to measure you actual efficiency, then set it correctly in Beersmith.

On that note, I personally find it easier with Beersmith to set my total efficiency as my mash efficiency, set the batch volume as my desired post boil volume, and all the post boil losses at zero. I do this because it's easy to hit my post boil volume every time by measuring accurately and knowing the boil off and grain absorption rates. Post boil losses to trub and fermenter however vary batch to batch, making the total brewhouse effieciency variable and a harder number to chase.

 

[ImpendingDisaster]

Thanks for the advice, folks. I will be measuring everything very carefully from now on.