aggravation with not hitting numbers...

[Redpappy]

Back in april of last year i purchased a SB Kettle. Just getting into AG ( BIAB style) i'm excited. First thing i do is I add 3 gals of water in to figure out my boil off rate. I plug all my info into Beersmith2. the first few batches that i did i got good numbers ( considering i'm still learning and all, I was getting about 68% Brew house Efficiency, and my numbers were close) At that time I was staying with my dad while my new home was being built. Now I"m in my house, i have changed my water from tap to Distilled. The last few my numbers have been lower and instead of hitting my 5.5 Gal mark, i have been hitting the 4.25 gal mark( whats going in the fermentor), as well as my gravity points. I brewed today, and it gets worse. I plan on buying in bulk, so I got me a mill (cereal Killer). Got my grains (pre milled from LHBS) and milled them again to .25. I was figuring that I would get at least a 75% efficiency. nope, came out to like 64%. on top of that I only got 4.5G, when it should of been 5.5. My SG was at 1.040 (estimated at 1.042). So even though the efficiency is lowered, I guess I boiled off enough water to keep my SG at target? I can tell I have a lot of trouble shooting to do...uggg....thanks for listening to me rant

I'm done ramping, I do have a question though.... Does tap water have a different boil off rate then Distilled water? I'm just wondering if the minerals play a part in it or not. I figuring I need to start over, and check my boil off rate, and then go from there.

 

[RPh_Guy]

Does tap water have a different boil off rate then Distilled water?

Mineral content won't make a significant difference with regard to boil-off.
Consider adjusting your water to hit mash pH 5.2-5.6 (measured at room temp), style flavor minerals, and neutralize sparge alkalinity.

It sounds like your boil-off rate changed when changing the heat source.

Different crush size will impact grain absorption and mash efficiency.
Just dial in your new loss rates and remember it's not that important to hit particular numbers. We aren't building rockets.

Once you start using your mill, that should help with consistency.

I calibrated a yardstick with my kettle volume, so now I can measure volume throughout the boil. This helps me hit my pre-boil volume and boil-off volume with very high accuracy.
I also account for thermal expansion when measuring. Mash temp is roughly 2% larger than room temp and boil is 4% larger than room temp.

Hope this helps.

 

[day_trippr]

I'm pretty sure BS accounts for temperature effects on volumes, but these are pretty huge "misses" wrt volume vs gravity at the critical junctures. While the boil off rate may have changed that's not what's causing the efficiency issue, and you'd think double-milling down to a .025 crush would send the equation in the opposite direction.

I don't do BiaB so I don't know where the issue lies but it has to be what's coming out of the mash tun...

Cheers!

 

[madscientist451]

It may take a few more batches to get your system and methods dialed in to hit the numbers you want. I'd tackle the volume problem first. Since you were 1 gallon short, just re-brew the a similar beer and add 1 gallon to your total water used.
To hit your gravity numbers, the easiest thing is to add more grain and forget about efficiency.
If you are buying grain in bulk, do you really care if you use an extra pound of base malt?
Another option would be to get a round cooler, put your BIAB bag in that and manually recirculate the wort for the last 10 minutes of the mash.

 

[RPh_Guy]

Does recirculation increase efficiency?

 

[madscientist451]

Better efficiency by re-circulation? I think that's a good question. Mega breweries
have mechanical stir systems built into their mash tuns. Since they squeeze every penny of brew out of their grain. I suppose research has shown that's the best way to do it. On the homebrew level,
I think you can get just as good results by stirring 2-3 times during the mash, but when doing that I noticed the mash temperature would go down. This is partly because I run lots of small experimental batches, usually 3-4 gallons. If you are running 10 gallon batches, there's a lot more thermal mass to hold the temperature.
Anyway, I decided to skip the stirring and go do something else for an hour or more during the mash. I'll recirculate for 5-10 minutes at the end and I usually hit my expected numbers. But I'm a lazy brewer and lately I've just been adding more grain at the beginning.
Here's an article about efficiency issues:
http://brulosophy.com/2015/09/10/6-tips-for-dealing-with-efficiency-problems/

 

[Cape Brewing]

I wouldn’t use distilled at all unless you have extremely hard water and then I would only use it to dilute to a small extent. If you don’t want to use tap water... use spring water. Distilled has been stripped of all of the minerals yeast needs to properly ferment.

In my limited BIAB experience, I always saw knocked down efficiency numbers just from the method alone. I’m guessing but I think the grain, in the bag, compacts too much and doesn’t get enough circulation (I dunno... that’s all I can think of... but I could never get a BIAB batch to hit numbers.

Crush, in my experience, has a habit of popping up a huge factor. My personal rule of thumb was to set my mill to the tight width of a credit card. That would crush the grain but also leave large pieces of the husks.

 

[Soulshine2]

distilled ,no . Filtered ,YES! As long as your tap water isn't extremely hard or sulphury ...i.e. - you can comfortably drink it from the tap, use it.
I do ZERO water corrections or additions. No issues, My beer tastes great . YMMV

 

[TechFanMD]

Honestly I don't think it is any of that. I'd take a good look at your calculations, and do each separately using online calculators to see if they match Beersmith. You need to account for grain absorption, boil off, and the total beer you want in the end (this is pretty basic, but close enough to find where you're going wrong).

You can actually measure grain absorption if you want by weighing the dry grain and then the grain after use and dividing the difference by 8.34 to find how many gallons got left in the grain. Nobody does this - but you have an issue so it might be worth checking into.

Curious- after you mash, how much do you have in your kettle after removing the bag? It should be 6 gallons or so.....depending on how much you'll boil off.

Also, you're not making some imperial vs US gallon error somewhere are you?

 

[Redpappy]

Last batch I had 7.5G left after mash. I usually have .75 to 1 gal left after I transfer to fermentor. So far everything has been in gallons.

I didn’t give it any thought about the RO water not having any nutrients. That may explain why my FG is off as well.... I thought I had more time time to play with Bru’n Water to figure out my water...

 

[TechFanMD]

Last batch I had 7.5G left after mash. I usually have .75 to 1 gal left after I transfer to fermentor. So far everything has been in gallons.

I didn’t give it any thought about the RO water not having any nutrients. That may explain why my FG is off as well.... I thought I had more time time to play with Bru’n Water to figure out my water...[/QUOTE

I would be shocked if water chemistry made that much difference.

I’m stumped on your volumes. How do you go from 7.5 gallon after mash down so low after boil? Do you have a leak somewhere? That’s an unheard of amount of boil off even in super low humidity with a hard boil.

 

[Redpappy]

No leak. I’m not sure.... I started with 8 gal and finished with 4.5... I can account for .75-1 gal left in kettle. I squeeze my bag as well as let it hang for a spell....

 

[TechFanMD]

Yeah - weird. Nobody gets a boil off like that....and if they did OG would be crazy high and you’d have to add water to dilute it to get to OG.

 

[betarhoalphadelta]

I wouldn’t use distilled at all unless you have extremely hard water and then I would only use it to dilute to a small extent. If you don’t want to use tap water... use spring water. Distilled has been stripped of all of the minerals yeast needs to properly ferment.

Distilled on its own is not good practice, of course. Distilled+minerals is perfect, however, because it allows you to create the unique water profile you want for your batch. In that respect, it's actually better than bottled spring water because you know what you've got.

Where I live, the tap water is decent enough for drinking, but not particularly good for brewing. So I do RO+minerals and it made a significant improvement to my beer with just that change.

 

[betarhoalphadelta]

I agree with others that job #1 is figuring out your volume issues. First things first...

Buy a metal ruler (without cork backing, just straight metal like this). Calibrate the ruler with measured water in 1/4 gal or 1/2 gal increments such that you know exactly how much liquid you have from the bottom of the kettle to known measurements.

I've attached an example spreadsheet for my own kettle which shows what I'm talking about. This will always give you an easy way to know EXACTLY how much liquid is in the kettle. And the fact that it's a ruler without the cork backing is that you can just dip the ruler in to the bottom of the kettle and measure even with wort in there.

This way you'll know exactly how much water you start with before the BIAB mash. You'll know exactly how much wort you have preboil (we generally assume .1 gal liquid loss per 1# of grain, but yours may be different). And you can measure your volumes both during the boil and at the end of the boil to truly know your boil-off rate.

So get ALL that dialed in to the point where it's the same every batch. Then we'll work on efficiency. But you can't really figure out your efficiency until you know your volumes, so starting with efficiency is the wrong tactic.