First BIAB, Questions for Second

[Oyarsa]

I brewed my first BIAB a couple days ago (an oatmeal stout). It went...well...ok.

I used a Darkstar Burner which I've used a couple of times before with a 32 qt aluminum kettle. This time I used my new Megapot 1.2 10 gallon kettle. I tried to calculate the amount of water needed, but misread the calculation and started to add 0.25 gallons per lb of grain rather than 0.25 quarts. My gut said that was wrong, so I decided to start with 8.5 gallons of water for a 13 lb. grain bill. Unfortunately, the kettle leaked very slightly from where the barb connected to the ball valve. One drop every 5 to 10 minutes or so. The recipe didn't state a mash temp, so I decided to shoot for somewhere between 150-158 degrees with a temperature of 168 prior to adding the grain. I overshot that because I wasn't watching and ended up at 180 (based on the kettle thermometer), so I added ice to bring it down to 168, added the grain, and the temperature slowly crept down to about 160. I added a little more ice, which dropped it to 158, so I covered it up (on the burner) with a sleeping bag. I left for an hour and when I came back, the temperature was at 140. Oh well...RDWHAHB.

When I removed the grain, the water level dropped only to 8 gallons. I figured I'd better make every grain count, so I squeezed the bag fairly well, then started the boil. I added Fermcap since the water level was so high. I planned to boil off the extra water, so I boiled for an hour and a half (thinking 1 gallon per hour) before adding the hops for the 1-hour boil. I could not monitor the water level due to the copious amounts of steam. I had a very slight boil over with the hops.

At the end of the hour, I turned off the heat and checked the water level. Somehow, I had made it down to 4 gallons. I started cooling, though, I'm beginning to think my immersion chiller is a bit small for the kettle. The whole thing fit inside the kettle in order to reach the bottom. I could only find one hose, so I hung it off the side of the kettle. This covered most of the coils and I figure it helped with cooling the hotter, top layers of water.

So, I transferred to my fermenter, added a gallon of water, and tested the specific gravity. I was at 1.060 for a recipe calling for 1.062. Not bad. I aerated with a slotted spoon for a bit and added the yeast. All-in-all a success, but there are things I'd like advice on...

1. The kettle got quite sooty. If I remember correctly, that could be due to too much oxygen, so I just need to close the airflow regulator a bit, correct?

2. The paint is chipping off the Dark Star burner, particularly where the kettle sits. Will this be a problem, or is it common/normal?

3. Any suggestions why the temperature dropped so dramatically and/or how to prevent it next time? There was airflow under the kettle that wasn't completely enclosed and it was quite a cold day. Maybe that was it? Or the ice water hadn't dropped down to the thermometer yet despite stirring? I didn't add that much...

4. Does using a bag for hop pellets help with preventing boil-overs? I really didn't expect it considering the size of the kettle, the water level, and the fact that it happened close to the end of the boil.

5. Is an immersion chiller more effective with a slow, thin stream of water, or with the water turned on higher? The water coming out of the chiller even at the beginning does not seem THAT hot. I figure that the longer it takes the water to progress through the coils, the more heat is picked up and therefore less water would be used. Is that correct?

6. Suggestions for cleaning the kettle? I got most of the soot off the bottom, but there's still some. The inside bottom has a film/discoloration/residue or something...

Any other thoughts/suggestions?

 

[downzero]

1 and 2, no idea. Sooty sounds rich to me, probably need more oxygen.

2, I've never seen that much temperature drop. I used to mash in and just let mine drop naturally and only lose a few degrees. You must be brewing in a very cold room.

3 Your kettle is too small for 5 gallon BIAB. You need a 15 gallon kettle at the gravity you're pushing for. You'd probably be fine if you were brewing a session beer, bitter, or a lager, but with a bigger grain bill, you need more space. With proper space in the keg, hops will actually keep the foam down. Even a tiny addition of hops at the beginning of the boil helps starve off the foam.

Adding ice to your kettle suggests to me that you used water of an unknown profile, which is never a good idea with all grain. All grain is sold as a modest upgrade from extract, but it introduces new things to worry about. Among them are mash ph and water profile becomes a much bigger deal. Next time shut off your burner and wait, or pour off some water and add some cold water. Ice from unknown water is never a good idea. Your water might have made great extract beer before for all I know, so don't take this the wrong way. But don't be surprised, especially with lighter beers, if unknown water introduces some tastes you'd rather do without. I learned this the hard way, so I'm sharing this for your benefit. With a roasty stout you may not notice chlorine or other tastes; with a wheat beer, you will. BIAB or 3 vessel, all grain is all grain. Your water and its mineral content is now completely up to you, whereas with extract, those things were done for you.

This also means you need to have a ph meter and monitor that as you mash, and be prepared to add acid to bring mash ph down if it's too high. With dark beers such as this one, that is unlikely to be an issue.

4 I still use hop bags, both for dry hopping and boil hops. I am considering a stainless basket for kettle hops because I'm concerned about possible utilization issues, but really that probably isn't a concern.

5. An immersion chiller is always going to be most effective with the flow rate up at the highest setting. The difference might be a little or a lot. The colder the water is that is in contact with the coils, the more chilling effect there will be. Slowing the flow rate will reduce the difference in temperature as the water warms. The difference in temperature, aka, the dT or the "delta-t" is a huge factor in cooling. Thinking of the water as "moving" is probably messing up the way you're thinking about this. Imagine the water was stopped in the cooler at an instant in time. Is colder or warmer water going to cool better? I think we both know the answer to that. Now take that point in time and iterate it over your entire chill time. The same effect occurs dynamically as statically. I would understand not wanting to "waste" water, so if the outlet temperature is substantially similar at a lower flow rate, then go with it, but the answer to your question is that the most flow with the coldest possible water will create the maximum chilling.

6. I wouldn't waste your time cleaning the bottom of your brew kettle. Beer doesn't come from the outside of the pot.

Suggestions:

Use software to calculate strike temperature, adjust recipes, and model things that you will later measure. Use your measurements to calibrate your expectations about how your equipment will work for you. Keep your burner on very low to maintain your mash temperature if needed.

Take good notes every brew day. This includes volume measurements, which I use a piece of PVC pipe with lines drawn on it in sharpie marker. Calculate mash temperature, boiloff volumes, preboil gravity, precisely measure every piece of grain and hops that go in your wort, etc. This costs essentially nothing. Your tools, like a ph meter that is calibrated, a hydrometer, wine thief, cylinder for measuring gravity, thermometer, etc., should already be things you have. Write down what these instruments tell you! I see checklists/sheets/instructions that come with all grain kits and I have even considered printing them so I don't forget to measure some aspect of the brew day.

Read the water chemistry primer and then follow it. 1/2 tsp of CaCl and CASO4 and adjust from there. Have lactic acid and a syringe handy to adjust mash ph with your meter.

Software will solve a bunch of your identified problems. Taking measurements and adjusting the software will get you closer every brew day.

I used to think a lot of the above was BS. I wasn't always so anal about this stuff because no matter what, you'll have beer at the other side of the fermentation. But if you like the beer, you want to be able to make it again, right? That's the reward to paying attention and keeping solid notes. I do mine by hand and transfer them into Beersmith after I'm done brewing and the beer is in the fermenter.

 

[bgmac]

Lets see if I can help you with the Dark Star since I have one.

1. You are right about adjusting the air for the flame. Try to get it as blue as possible with the pot sitting on the burner. Yellowish flames mean that your air to gas mixture is off a little. Might need more oxygen, might need less. Mess with the air mixture plate and keep in mind, you will probably still have a little bit of yellow on the best setting just go with the most blue flame you can get. I think my air plate is set pretty much wide open.

2. On the Dark Star yes, the paint will burn off on the top and the wind guard sides some what. When I first got it, I ran it on full blast for like 30 minutes to get passed the burnt paint smell.

 

[MikeCo]

A 10-gallon kettle is fine for a 5-gallon batch with the grain bill you're talking about. I use one for bigger beers than that. If the water and grain fit i the kettle, it's big enough.

8 gallons is about right for the strike water for a full volume mash, but use a calculator for accuracy. It's easy and takes the guesswork out of the volumes and temperatures. Just google BIAB calculator. The calculator will also tell you whether the grain and water will fit in your kettle. Here is one example:

https://biabbrewing.com/brew-day-prep/biab-calculators-and-software/

I'd recommend just using the default for grain absorption until you get a better idea of the actual value from your own experience. Keep track of pre and post mash volumes in the future to get a more accurate value for your process. Whether you squeeze the bag can make a big difference in absorption.

Are you brewing outside in a cold climate? That's the only way I can see the temperature dropping that much in an hour. Also, make sure your thermometer is accurate. Test it in ice water and boiling water. I use a hand-held instant-read digital thermometer.

 

[Oyarsa]

Sorry to have abandoned my post for a while. Thanks for the comments/suggestions.

I found the water profile of my tap water and purchased the Beersmith 3 mobile app. I'm still working on figuring out how to make use of the water profile/equipment profiles in Beersmith.

I will definitely start taking better notes. It's something I really need to get in the habit of doing for my brewing, and now that I'm getting into film photography, for that, too.

Thanks for the info on the Darkstar burner, Bgmac.