My first BIAB, first AG

Post #1 made 3 weeks ago
I joined awhile back and used the amazing info here to build my BIAB setup (a budget rig, certainly) and have FINALLY gotten to do a true SV batch. I would appreciate any feedback on my process and in particular how I did filling out my actual numbers on BIABACUS. I have a new appreciation for the document after actually using it! The ability to measure volume in the kettle with a ruler is a game changer! So anyway.
Czech Pilsner, recipe info in BIABacus file. 90 minute mash at a target 152°F, did not maintain temperature well. Had dropped to 147°F after 20 minutes, 142°F after 60 minutes and 136°F by the end. I pulled the bag and reheated to "mashout" around 164°F for 10 minutes. This was just a shot in the dark to possibly make up for the low temperature rest for most of the mash. I was actually excited about a 77.5% efficiency on my first try. I blame a particularly windy day and lack of copious insulation for my temperature woes.
Target was 1.044 and actual was 1.040. I pulled 1 quart of the preboil wort to make a "shaken not stirred" method starter. I also had a boil over (was not ready for that AG hot break!) I also had significantly more trub than originally expected (no way to suspend my bag to make a hop sock) so not sure what my actual evaporation was. (Did I mention how windy it was?) I ended up half a gallon (2 litersish) short of my volume in fermenter target. My GIF is 1.055 just slightly above my 1.054 I'm trying to figure out how to attach the BIABacus file but keep getting a "file too large" error. Thanks for any and all insight
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Re: My first BIAB, first AG

Post #2 made 3 weeks ago
Dreadpiratewes - Relax, you will get beer. :drink: Congratulations on getting through your first brew. :clap:

1) Yes, the BIABacus is terrific for lots of reasons.
2) You wanted a 90 minute mash @ 152 ºF according to the recipe you were following, but experienced falling Mash Temperature due to wind and maybe a need for kettle insulation. 147 ºF after 20 min. isn't too bad, even assuming that you had measured the Temp after dough-in and stirring just before you covered your kettle. At that point (and others) you could have stirred the grist gently and applied heat to get back to 152 ºF while keeping the bag off of the kettle bottom (to avoid melting the bag). Your Temp. continued dropping over the remaining 70 min. to levels that are not optimal but the mash will still have extracted and converted sugars. It is probably why your Gravity Into Boil (GIB) is low but not horribly so. If you read elsewhere about mash times and temperatures you will see some strange theories but they manage to get beer - Pilsners most often. Next time you brew, use some kind of wrap around all but the kettle bottom after the flame is out. Check the Temp. @ 30 min, remove the wrapping and stir gently while heating back to target if the Temp. has dropped >5 ºF (~3 ºC). You get to choose how often you check and whether or not you re-heat based on experience. Next brew day, you'll have twice as much experience! I check once at 45 min. and stir. The old down comforter I use for insulation works well. Efficiency numbers are reference points for you to use making comparisons among your various batches. Do not get hung up on them, please.
3) Taking an aliquot of wort for starter sounds good. It does have an effect on GIB / VIB / VFO and VIF numbers that cancel one another out so keep that in mind. You will be able to make comparisons when you use this technique, but if you make a starter some other way, numbers will vary.
4) Mash-out temperature is always higher than mash temperature. It is inherently on the curve towards boiling. Among the reasons for "mash-out" is to lower the viscosity of the wort to improve drainage from the bag. Notice that the full bag is still immersed while heating to mash-out target. Do not melt the bag on the kettle bottom and do not heat the wet grains to a temperature where those dreaded tannins become extractible.There is an upper limit to mash-out temperature. I only do it when I have >30% rye malt in the grist. Otherwise, I pull the bag @ 90 min and heat to boil.
5) Boil-over occurs as heat is applied during the slice of time when liquid is changing to gas and proteins are precipitating simultaneously. The newly formed solid particles provide nucleation sites for gas bubbles and they all head for the surface at once. Turn the heat down immediately, but expect a repeat when you turn it on again. I have a stainless stirrer that reaches the kettle bottom. As the temperature approaches boiling, I slowly scrape the kettle bottom and rarely have any foaming problem. You cannot look away for an instant doing this. Stop when the boil is constant and continue to watch for foaming for a full minute.
6) I use a hop sock wrapped with copper wire to keep it closed and the wire is long enough to wrap a kettle handle for retrieval. It can be tricky to open it and charge more hops later, but it works.

Hope for a less windy day, and good luck. :salute:
Last edited by ShorePoints on 01 Apr 2019, 01:29, edited 1 time in total.

Re: My first BIAB, first AG

Post #3 made 3 weeks ago
Thanks @Dreadpiratewes for the great read and congrats on your maiden voyage. Also, thanks to @ShorePoints for his always excellent answers.
Dreadpiratewes wrote:
3 weeks ago
I'm trying to figure out how to attach the BIABacus file but keep getting a "file too large" error.
This worries me Pirate. I just did a test post and attached a BIABacus file with no problems. I think the first things to check are that the extension on the file is .xls (although .ods will do). Also check the file size of the BIABcus file you are uplaoding. It should be less than 500KB.

Be nice to see you being able to upload your file correctly.

Congrats again :salute: ,
PP
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Re: My first BIAB, first AG

Post #4 made 1 week ago
Oops I didnt receive notifications on your responses gents. Thanks for the insights! I'm optimistic and excited for the outcome of this brew. I am quite happy with the numbers I achieved but wanted to share my challenges with you men of great experience as I find in the world of brewing for every obstacle there are many people willing to share how they overcame that exact issue. I'm still working on the file. I had to work off of a spreadsheet app on my phone because my laptop was on the fritz. I fixed the computer (HDD to SSD upgrade!) So I will be better able to manipulate the excel file. Thanks again for the responses and I do apologize for not acknowledging them sooner. I'd hate for you to think me unappreciative.

Cheers!
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