What happens if you don't get complete conversion?

[user 29674]

I have my preboil sample cooling, and I just went and looked at it and there are globules of... something... floating in it. I think it may be starch from the grain? I didn't do an iodine test, and the batch is boiling now. I'm running out to get some iodine while SWMBO keeps an eye on the boil, but what will happen to the brew if that is incomplete conversion?

 

[user 29674]

Hopefully this is little pieces of grain or break material of some sort that will settle out in the fermenter. Ugh.

 

[KYB]

I'm sure it will be fine. Worst case, lower efficiency and less abv.

 

[bob1852]

RDWHAHB!!!

you often won't get "complete" conversion in AG (90% is a great target).

BUT, something floating in your sample has nothing to do with conversion. Most likely some flecks of husk or something got into your kettle while you were lautering. Shouldn't be a big deal.

 

[ILOVEBEER]

I was curious about something....how can one figure out their efficiency without software?

 

[user 29674]

I was curious about something....how can one figure out their efficiency without software?

Its just math. You take the maximum theoretical extraction for your grain, and divide your gravity by the maximum. The decimal you get is your efficency as a percentage.

IE: maximum potential extraction of your grain is 1.030 and you get 1.020... 20/30 = .666666666 = 67%


I went to Kroger and got some iodine and no color change. I pulled the sample as it was heating up to boil, so probably near 190*. I'm pretty sure its break material, or something totally normal. I've never brewed anything this light in color (BM's Centennial Blonde) so maybe this is supposed to be in there and I've just never been able to see it before.

 

[user 29674]

Now that I'm looking at a post-boil sample I'm 90-99% sure that its break material. Its settling to the bottom pretty fast in the sample jar. I guess I've just never noticed it because all my beers thus far have been darker.

 

[snail]

Just to add on to what Aubrey said...
Here is a malt chart to find your max potential gravity. Then just use the formula he showed you.

https://www.homebrewtalk.com/wiki/index.php/Malts_Chart