Like many immigrant descended 1st or 2nd generation Americans, I grew up eating dishes that existed in a kind of "ethnic food time warp"--the ethnic foods and recipes that my grandparents knew and brought with them when they left their countries of origin. So it was the German recipes of the mid-1920s that my Oma passed on to my mother, and my mother to us.
Thus, I can verify that some of the recipes in this cookbook are classic, old German recipes. Whether or not the other recipes are "modern" German cooking, I'm not sure. Also, as with all ethnic cooking, many recipes passed down in families have regional variations. This cookbook lists many variations on common dishes, and I've often been able to find my grandmother's version of a dish in one of the variations listed for a particular recipe.
Virtually all of the recipes for roasted, stuffed poultries (duck, chicken, goose) are the same as my grandmother made them, or have variations listed that are the same. The pork, beef (Rouladen!), and organ recipes (tongue!) are also mainly as my grandmother made them. Even the recipes I hated as a child--or still hate!-- such as Eintopf (all the vegetables you hate in one watery soup!), are here in all their authentically horrible glory.
Some of the recipes in this book call for prepared packets such as the Dr. Oetker prepared mixes or packets. My grandmother used some of Dr. Oetker's prepared mixes (such as the Rote Gruetze, Vanilla Sugar, Sahnesteif). However, the overwhelming majority of the recipes -- I'd say 98-99% -- in here call for nothing but good quality meat and produce.
Most or all of the traditional meat recipes and sauces (gravies made from various broths or roast drippings) have some or all ingredients in common with our German family recipes. Same with dumplings, pancakes, noodles (Spaetzle!), and many of the different ways of preparing potatoes and other vegetables (such as cabbage, red cabbage, cucumbers, or leeks).
If you're REALLY into authentic cuisine, you might want to check old copies of the magazine "Meine Familie und Ich" for German recipes. My grandmother subscribed to that magazine for various years in the late 60s and 70s (and to Amerika Woche, of course). Not sure where you'd get them if they aren't already in your family, but libraries might have them. (Of course, the magazine and its recipes are in German, so it helps if you know a little German...)
A couple things to note: this cookbook is in British English, not American English. There are translation tables for some US versions of British terms on the insides of the front and back covers. There are also metric to imperial standard conversion tables as well (unless you are lucky enough to have cups with metric AND imperial measures, which I have and inherited from my German grandmother!).
Another great thing about this cookbook are the many tips and tricks listed about cooking, mixing, whipping, browning, larding, and food/produce quality-- for example, how to tell if eggs are fresh, a few days old, or a few *weeks* old. The method described on page 260 (floating the eggs in a bowl of water and seeing how they float -- or don't) is exactly how my grandmother taught my mother, and how my mother taught us.
You'll also find valuable tidbits on making sauces, reductions, gravies, drippings, jus, or even how to make your own mayonnaise. If you didn't grow up learning these from your own mother, the methods listed may seem like too much work. But if you love good food, the time and effort involved can make the difference between a good-tasting dish and a GREAT-tasting dish. Schmeckt!