Weird BIAB process?

Northern Brewer General
1

I have a friend that offered to do a BIAB session with me. I’ve done nothing but extract so far so this was exciting. I read up on the process and was not suprised when we bought the following fir a 5 gallon batch:

8.75 # belgian pale
1# candied sugar
1 oz Citra 60min
1 oz centennial 1/2@30, 1/2 @10
1 oz cascade 5 min
Danstar Belle saison

We were going for a white IPA

Once we got back and he unloaded his gear I was immediately confused. He only had a 5 gallon pot. …
He heated 2.75 gallons to 155 and wet mixed in the grain. It rested at 150 for 90 min. No sparge but we did squeeze the bag through a colander. We ended up with about 2 gallons. Brought to boil through hot break and added the sugar. 60 minute boil, hop additions per above. Ice bath cool, added water to almost 5 gallons, pitched yeast, and is bubbling away right now with a nice thick Krausen.

I asked a few questions but didn’t want to insult him. He said he always does it that way and it turns out fine. We forgot to get an OG…of course. I woke up the next morning and it was already bubbling with a Krausen forming. …I went ahead and took a gravity then. …1040 :cry:

Questions… Has anyone ever done it this way? ?? And how much could the gravity drop overnight??
What do you all think the outcome will be?

2

Personally I think partial boil is a fantastic idea. It will probably turn out wonderful. The advantages are obvious – easier smaller boil, faster post-boil chilling. I might want to be doing this more in the future!

The effects of partial boil is mostly just that the beer will end up slightly darker than full boil, and you also might notice the IBUs are a little lower than the recipe intended. Maybe that matters to him and maybe it doesn’t. I wouldn’t much care either way, and it’s pretty easy to jack up the IBUs a little on purpose to compensate, maybe use an extra 15% bittering hops or something like that.

If there was a krausen forming already, then the gravity probably already started to fall by a couple of points. It’s possible that the real OG was as high as like 1.043-1.044, something like that. A little low, but just call it a session IPA then, no big deal.

3

[quote=“dmtaylo2”]Personally I think partial boil is a fantastic idea. It will probably turn out wonderful. The advantages are obvious – easier smaller boil, faster post-boil chilling. I might want to be doing this more in the future!

The effects of partial boil is mostly just that the beer will end up slightly darker than full boil, and you also might notice the IBUs are a little lower than the recipe intended. Maybe that matters to him and maybe it doesn’t. I wouldn’t much care either way, and it’s pretty easy to jack up the IBUs a little on purpose to compensate, maybe use an extra 15% bittering hops or something like that.

If there was a krausen forming already, then the gravity probably already started to fall by a couple of points. It’s possible that the real OG was as high as like 1.043-1.044, something like that. A little low, but just call it a session IPA then, no big deal.[/quote]

Word! Thanks man. That’s exactly what I was going to call it lol. It got down to 100 in 10 mins and we poured in the cold water; straight down to 70. The wort was like syrup before the water. Do you think that the OG was low because of not sparging?

4

The OG was low primarily because the grain bill was low. Only 8.75 lb grain and a pound of sugar? That’s pretty low for 5 gallons. The lack of a sparge probably didn’t matter as much since the bag was squeezed well. If you wanted higher OG then next time use an extra couple pounds of grain.

5

What is your opinion of Brewer’s Friend? We used it to determine the grain bill… What do you think the efficiency is for a BIAB?? Looks like about 55% (according to Brewer’s Friend). I admit that it has never matched results when I have used it to reverse engineer a batch I have made. How do you determine your grain bill?

6

I have never used Brewer’s Friend. I use StrangeBrew, which is a really old software with capabilities similar to BeerSmith. I’ll pump it in now and then update this post with results…

EDIT: Oh wow, yeah, efficiency kind of sucked. StrangeBrew gave me around 53%. You should have gotten closer to 1.056 gravity assuming a standard efficiency around 75%, which should have been easily achievable. Yeah, that’s the result of no-sparge, and I guess the squeezing didn’t help as much as I would have thought. Hmm. Next time, maybe just crush harder, or rinse the bag with some warm water, and the efficiency will jump way back up to around 75%.

To determine a grain bill, you need to brew a couple of experimental batches first. Then for each batch, add your gravity units plus efficiency to find out what your brewing process “constant” is. So, like in this case, you’d take the 42 from the assumed OG of 1.042, add the efficiency of about 53%, so your constant then would be 42 + 53 = 95.

That’s very low! Normal constants would be between 125-145. But anyway…

You can use this constant to estimate your efficiency in the future. So next time, you want to brew a 1.055 beer, but don’t know what your efficiency to assume in your software? No problem. Take your constant of 95, minus 55, equals 40. So you should expect efficiency of 40%.

That’s actually pretty terrible. A simple rinse of the grain bag should bring your constant way up to around 125-130. In that case, for your 1.055 beer, 125 - 55 = 70%. Much more reasonable. Same thing would work for a 1.080 beer. 125 - 80 = 45%. Kind of sucky, but that’s just what happens with strong beers, unless you sparge a ton and then plan on boiling for 90-120 minutes instead of just 60 minutes. With a little more experience and a really hard crush, your constant will grow in value until it’s more like 145, which is where I’m at now.

7

Just bottled this and it got down to 1004. That at least got me to 5% abv. Doing this again today and will definitely sparge. Thanks Dave for all the good info.