Beer Brats are a summertime staple, but sometimes it feels like there are more ways to cook a brat than eat a brat.
One tradition insists simmering brats in beer and onions an hour before grilling are the keys to flavor town. Other swear you must grill the brats first, and then boil. A large cadre maintains beer won't penetrate through the casings unless you first prick the surface with a fork. But, a more tender sect cries if you do poke holes in the casing, all the juices will flow out and the flavor will be lost.
Over lesser issues, wars have been fought. Families torn apart. Tires punctured.
We won't settle this debate today, but can put one question to rest. Does beer flavor penetrate into the brat during simmering? How deeply, and does it matter if you puncture the casing?
Our test is simple- we simmered natural casing brats in dyed beer for 15, 30 and 45 minutes. Half the brats were punctured by fork tines every half cm, the others left intact. And then we cut the brats open to see how far the dye penetrated.
Not every dye is heat-stable and can tolerate boiling. And most dyes are large complex molecules which will not diffuse very quickly or very deeply into the meat. But, in earlier experiments we discovered copper sulfate moves through food almost as quickly as salt, and much faster than many flavor molecules, like onion or garlic. So we filled an enameled pot with simmering beer and copper sulfate, lowered in the brats, and waited.
NOTE COPPER SULFATE IS POISONOUS- DO NOT CONSUME DYED BRATS
The brat casings turned green in minutes, and looked like gray pickles.
As each brat was removed from the broth, patted dried and cooled, the aroma of beer was clearly present. Slicing open the brats revealed the dye penetrated very quickly, about 1-2mm.
Puncturing DID NOT increase the depth of penetration, even around the punctures. In fact, I cut open the end of a brat before simmering, and the dye penetrated bare meat just as easily as casing-wrapped pork. While natural casings were once used as condoms, and can exclude large molecules or sperm, at high temps and after stretching they are pretty porous. A few punctures won't matter by comparison.
In later tests NOT involving toxic copper sulfate, I tasted slivers of brat at the surface and deep in the interior. These tests confirmed the flavor was concentrated in a thin surface band. The band is around the thickness of the pork grind. In other words, flavor molecules are not diffusing in through atomically small pores, but initially flooding in around the cut edges of the ground meat. Then, as you can see by the more diffuse edge on the 45 minute brat, very slowing oozing towards the center.
So now we know:
- Simmering in beer actually does add flavor to a thin band of meat under the casing
- Puncturing with a fork does not accelerate beer broth penetration (but does cause the brats to shrink a bit).
- A 15 minute simmer is nearly as effective as an hour.
- Since beer broth flavor is limited to the surface, a grilled brat sliced and covered with a beer sauce will taste nearly the same as one first boiled in beer. The texture will be different, but not the flavor. So you are free to boil in (horrors) salt water, and later toss sliced brats in a reduced beer sauce. Or not.
Good luck keeping peace in your family.