Have you ever noticed that the estimated beer color in Bru’n Water doesn’t quite match the calculations in BeerSmith?
In fact, these numbers can be off considerably at times, and it makes you wonder which one you should rely on. I also found that the darker the beer I was brewing, the larger delta I had in estimated beer color.
I had given up trying to sort it out, and simply relied on BeerSmith for my Color (SRM) calculation.
This got me thinking. If my Estimated Beer Color was off in Bru’n Water, was this skewing my water adjustment calculations? After all, darker roasted malts can impact your mash pH right?
I hate it when I can figure things out. There should absolutely be no reason why the Estimated Beer Color in Bru’n Water wouldn’t match the Color (SRM) calculation in BeerSmith. What was I doing wrong?
Then it hit me. It was actually pretty obvious when I looked a bit closer at the heading values in Bru’n Water.
The secret lies in SRM vs. Lovibond.
SRM vs. Lovibond
Let’s get back to the SRM vs. Lovibond question. What’s the difference?
SRM is mainly used to describe the color of a beer. Lovibond is used to describe malts, specifically the color or darkness of that malt.
Given that, the Lovibond rating of a malt, factoring in the various malts that are used in your Grist, will generate a color rating (SRM) for your beer.
Let’s use a simple example. If we brew up a Pilsner, using only German Pilsner malt, that malt has a Lovibond rating of 1.7L. If we plug that into BeerSmith, the color rating of that beer is 2.8 SRM.
SRM and Lovibond are not the same when it comes to the color of your beer.
Bru’n Water vs BeerSmith Estimated Color
If we take a further look at the problem, comparing Bru’n Water to BeerSmith you’ll see what I’m referring to.
Let’s use a Schwarzbier as an example, as you’ll see a wider discrepancy with darker beers.
If you compare both images, you’ll see the grain bill is identical. In the first image, Bru’n Water’s estimated beer color is calculated at 27.7 SRM. In the second image, BeerSmith’s calculated color is 23.4 SRM. Quite a bit of difference.
If you look closely at the Bru’n Water image, paying attention to the header, you’ll see the Color Label is in Lovibond.
There’s our problem. BeerSmith lists the grain color using SRM, and it needs to be converted to Lovibond if you want to use it correctly in Bru’n Water.
Converting SRM to Lovibond
So how do we convert SRM to Lovibond?
It’s really not that difficult, since there are a number of calculators that will do the job for you. That’s a whole lot easier than running the calculations manually.
Using the calculator, we need to convert the grain color in BeerSmith from SRM, to the expected grain color in Bru’n Water in Lovibond. That gives the following results.
Using the newly converted grain color (L) values, we get an estimated beer color of 22.8. While this still doesn’t get us to the 23.4 SRM that BeerSmith is calculating, it’s a lot closer than it was previously. This difference may very well may be related to the underlying formula’s these different software products are using.
While I really don’t think this minor deviation is causing any issues with my water adjustments, this still drives the perfectionist in me a bit crazy. If anyone has any insight into what could be causing this minor difference, give me a shout in the comments below.