First BIAB 1 gallon, couple questions

[grittanomyces]

Getting ready to do my first BIAB 1 gallon batch, and as easy as it sounds, it's really easy to second-guess and wonder before doing it the first time. A couple questions:

1) I tried using the water calculator for a recent article here, but I have no clue how much will be boiled off, kinda making the calculator pointless. I'm fine if the volume comes out short, as I'm doing a SMaSH that I will be using generous hops, so I'm fine if utilization is lower by dilluting. But I don't want to end up with a low efficiency and too high of volume, resulting in a much lower ABV than I'm shooting for.

So what would be a safe amount of water to use for boiling on an electric stove?

2) I recall reading that mashing in around 160 should be good if I'm going to be insulating with a jacket. Does this sound right, and how much risk is there of ruining my ski jacket or sleeping bag at that temp? I know I should trust those who've done it, but it makes me nervous.

Alternatively, I found during steeping with extract that my stovetop holds the temp pretty steady when kept on low with the lid off. Would it be better to do this? I'll admit that I still don't fully understand why a few degrees makes such a difference.

Anything else to keep in mind? Thanks for any advice.

 

[wilserbrewer]

1. Keep track of your volume as you progress, if you are running low top the kettle with a little water, and perhaps don't boil as aggressively. Conversely, if you have too much volume, Boil longer but still time the late addition hops around your end time.

2. Mash temps will not hurt a coat or blanket. For a 1 gallon batch, I would preheat the oven and stick the mash in a warm oven for the hour rest. This will keep your temp very steady. 160 is a good ballpark average strike temp.


Wilserbrewer
Http://biabbags.webs.com/

 

[gregfreemyer]

I have no clue how much will be boiled off

The biabacus calculator from biabrewer.info is complex, but it will let you put in the dimensions of your kettle and give you an estimated boil off. That forum has user restrictions when you first register. You have to post an intro message before it turns on some privileges. I think downloading the calculator is one of the things you can't do until you do that first post.

- the intensity and length of the boil will effect it. So will the surface area of your pot.

- a slow boil is all you need as long as the water is circulating (or so I've read)

- my pot is undersized, so I use a slow boil to reduce boil off.

I boil off about a gallon when making a 5 gallon batch (20%), so for your 128 ounce batch I would expect a minimum of 25 oz of boil off or about 3 cups. I suspect a roiling boil might be twice that.