Most Maibock recipes are very simple. The beer should be pale and better attenuated than other bockbiers, so the grist is usually 100% base malts. Crystal malts are not needed because caramel flavor and the extra body that crystal malts add are not desired. In the same vein, there is no call to add CaraPils (or CaraAnything) to your grist. A simple mix of Pilsner, Vienna, and Munich malt is ideal.
The grain bill for a Maibock can be as simple as all Pilsner malt or all Vienna malt, but a little bit of light Munich malt (around 10 °L) — perhaps as much as 25% of the grain bill — adds some malt character that is typical of a bockbier. So, two possible Maibock grain bills would be roughly 75–95% Pilsner malt with the rest being light Munich malt or 80–95% Vienna malt, with the rest being Munich. You could also use a blend of Pilsner and Vienna for most of the grain bill, and round it out with a little Munich. Given that these base malts are your only grains, they should be of the highest quality.
If you want to add a bit more malt character, you could also add either a small amount of dark Munich malt (around 20 °L) or a tiny amount of aromatic or melanoidin malt. If so, keep the amount of dark Munich under 10% of the grist and use less than 2% of aromatic or melanoidin.
If you are an extract brewer, I would strongly recommend supplementing the malt extract with wort from a partial mash. This will give the beer a full, malty aroma and will help the wort reach a suitable degree of fermentability. Mash at around 152 °F (67 °C) and don’t mash out. Run the wort off to your brewpot and dissolve the early addition of malt extract in this wort. Hold the mix at 152 °F (67 °C) for about 5 minutes before beginning to heat the wort to a boil. This will give the enzymes from your partial mash wort time to work on the larger carbohydrates in the malt extract and raise its fermentability a bit.
Whether all-grain or extract, shoot for an OG in the 16–18 °Plato (SG 1.064–1.072) range and 6–11 SRM. (Those are the values given in the BJCP guidelines.)
If you are using “regular” (not undermodified) malts, a single infusion mash in the 152–154 °F (67–68 °C) range for 45–60 minutes should give you the appropriate degree of wort fermentability. Given that there are no specialty malts in the grist, this range of mash temperatures should work well. There is no need to do a step mash (with a rest in the beta amylase range) to produce a highly fermentable wort, because you are not looking to produce a dry beer, just a bockbier with a bit more attenuation than a “regular” bock or dopplebock.
If you use undermodified Pilsner malt as the bulk of your grain bill, a single decoction mash would work well. You can also do a triple decoction mash. The single decoction mash, however, will deliver everything that the undermodified malt requires and is a lot less time consuming. For a single decoction mash, mash in to 113–122 °F (45–50 °C) and hold for about 15 minutes. This should take care of any excess beta glucans in your malt. After this, pull your decoction (roughly a third of the mash) and bring it to a boil. When you stir the decoction back into the main mash, a combined mash temperature of 152–154 °F (67–68 °C) is what you should shoot for. Rest there for about 45 minutes, then mash and and proceed to wort collection.
Keep It Simple
A Mainbock recipe should be simple. Likewise, wort production can be very straight forward. A single infusion mash is all that is needed, although you can opt for decoction mashing if you use undermodified Pilsner malt. And, even though the beer is fairly strong, you are not dealing with an amount of malt that will strain the capabilities of most homebrew mash tuns. As we will see, the “make or break” part of brewing a Maibock is running the fermentation.
The next installment in this series will cover wort boiling and hops.