Monday, July 27, 2015

Mathy Stuff, Conversion, and Troubleshooting

Remember the early days of when you were in school and you were learning some math principle, and you asked yourself, when am I ever going to need to use this??  We've all done it, and decided that we'd never need it...but years later, we'd end up using those basic principles and skills so much and so often that we weren't aware of it.

The first time I discussed mathy stuff (i.e., converting recipes to small batches), the math was pretty simple...straight-forward division, with maybe a little rounding thrown in there for good measure.  Part of what I'd been trying to do with that was to figure out why some of the initial 1 gal batches I'd tried were so lacking in body.  By looking at the amount of fermentables in a 'good' brew and comparing that to what was in the recipe, I would then "do the math" to try to figure out where things might be lacking.  I know that looking at the total weight of grains, and doing conversions for extracts (dry or syrup) isn't necessarily a 1-to-1 direct relationship in all recipes, but it's a starting point.

Here's some conversion math from MidWest.  If you're really lazy, Jay's has a chart for you.  Home Brewer's Assoc. has some similar calculations. Northern Brewer has some gravity per pound per gallon calculations you can use, if you're up for that sort of thing, and BYO has some similar calculations.

In short, I opted to go with the conversions from MidWest, which look like this...
LME/grain : 4/5; that is, 8 lb of LME =~ 10 lb of grain
DME/grain : 3.2/5; that is, 6.4 lb of DME =~ 10 lb of grain

Carrying that a step further, the above conversions line right up with the LME/DME conversion of 1.25/1 (or, 1.25 lb of LME =~ 1 lb DME).

Simply for the sake of comparison, let's take a look at three of the 1 gallon recipes available from True Brews, using these conversion factors...again, this is simply for the sake of comparison.  What I've listed in the following table is the recipe, the total weight of the grain bill, and the estimated ABV specified by the recipe.

Recipe Amount ABV (est)
Amber Ale (pg 97) 2 lb 14 oz 6 %
IPA (pg 101) 3 lbs 6 %
Apricot Wheat Ale (pg 104) 2 1/2 lb 6 %

As you can see, all of these recipes utilize more than 2 lbs of grain for a 1 gal brew.  One of the early beers that I brewed as a 1 gal small batch was the Wil Wheaton VandalEyes PA, from Northern Brewer.  I really liked the body of the resulting beer, and if you use the conversion from above, the 1.5 lb of gold malt extract syrup is approximately equal to 2.34 lb of grain.  The 5 gal all-grain recipe calls for 13 lb, 14 oz of grain; converting to a 1 gal recipe (simply based on weight), that would be 2.775 lbs (2 lb, 12 oz) of grain.

Yeah, I know that this process that I've walked through isn't a 1-to-1 conversion, but it's a simple method that I've been looking at to give myself an idea of what a beer that results in adequate body looks like from the beginning.

Troubleshooting - Lacing and Head Retention
Like many home brewers, I've run into issues with the beer I've brewed.  Something that's on my radar at the moment is lacing and head retention.

So, here's the go-to brew when I'm out-and-about is Bell's Two-Hearted.  It's got a great flavor, great color, a really nice head (it usually still has a head when it gets to the table), and some really awesome lacing going on.  Most of the beers I've brewed haven't been like that...although, according to my tasting notes, the first rye ale I brewed did have some good lacing.  So, I started doing some research into what might be the issue, particularly for the beer I brewed with ginger.

In doing my research, I found a couple of reasons why there might be issues with head retention and lacing.  For the moment, I'm discounting the bottle cleanliness, as my cleaning process hasn't changed at all since I started; it's been consistent and I have had at least one beer with some good lacing.  This thread on HomeBrewTalk has some good input (talks about wheat, carapils), and it references an interesting malt chart.  This BeerSmith article includes some interesting tidbits for enhancing beer head retention.  Here's a pretty interesting BYO article on techniques for getting good beer foam, which includes a brief discussion of how boiling barley malt denatures a protein called LPT1, which leads to good bear foam.

In reading through these and other sources, the understanding that I've developed thus far is that base malts should lead to good beer foam, and using wheat and carapils can lead to good head retention and lacing.  Pretty simple at this point, I know, but it's a start.

Bell's Two-Hearted Clones
HomeBrewTalk Recipe
Recipe from the Home Brewer's Assoc.
BeerSmith Recipe

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