by Roger Bergen

Republished by permission from BrewingTecniques'
'Brewing in Styles' column, May/June 1993.

This is part 2 of a 2 part series. Click here to read part I.

BREWING WHEAT BEER
Wheat malt's characteristics have important consequences in brewing, especially in wort production. Wheat mashes are considerably more troublesome than malt mashes, and sticky mashes and slow run-offs are the rule. Those brewers fortunate enough to have upward-infusion mash vessels and rake-equipped lauter tuns will have a much easier time than most of us who struggle along using infusion mash tuns that were perfectly satisfactory until we started brewing wheat beer.

Because wheat malt is harder and less mealy than barley malt, extract yield increases substantially if the malt is milled somewhat finer than barley malt. Some mills, however, are not well designed for changing the roller settings in the middle of the run. Fortunately, premilled wheat malt is available for those who have this problem. Also, the finer particles will increase run-off problems for those with infusion mash tuns. The question of whether the potential hassles of finer milling are worth the gain in yield is a matter of personal judgment.

For the brewer with a typical infusion mash tun, wheat brewing is often a slow and laborious process. What follows is a distillation of the experience and advice of several experienced wheat brewers. You may not choose to use all these techniques, but be aware of them - you may need them.

Try to avoid grists that contain more than 50% wheat malt and large amounts of grist that produce a deep mash bed, at least until you are experienced and comfortable with wheat mashes. Wheat mashes are so sticky and generally gloppy that it's a good idea to keep them on the thin side, at least 1 bbl of mash liquor per 100 lb of grist. Use plenty of foundation water - at least 2 in. - over the false bottom plates. Mash in a proportion of barley malt first to ensure that some husk rests over the false bottom. Wheat malt can tend to ball up, especially if you don't have a premasher to do the really hard work for you. Be sure to mix the wheat and barley malt together as uniformly as possible; any layer or clump of wheat malt will blind the area below it and block run-off.

After conversion at your preferred temperature and time, you might consider remixing the mash with very hot water to raise the temperature to 76-78 degrees C (168-172 degrees F). The increased temperature will reduce the viscosity of the wort and mash and make run-off much easier, but it's an awful lot of work. To do this, heat an appropriate amount of liquor to boiling in the kettle, then underlet into the mash tun and stir like a madman.

One of the best techniques to promote good run-off is to rake the bed with your trusty canoe paddle during recirculation and sparging. Simply use the paddle like a knife to cut the bed in a crisscross pattern to within a few inches of the false bottom. Do this at the start of the wort recirculation (vorlauf) and at the start of the sparge. Thereafter, monitor the run-off carefully and repeat the cutting when it shows signs of slowing down, or about every 15 min, whichever seems best. Home brewers can do this easily using a kitchen or table knife. Because the danger of leaching out husk flavor is reduced, you can use hotter sparge water than usual, up to 80 degrees C (176 degrees F), to reduce wort viscosity, but by all means harden or acidify your sparge water as usual. Wheat mashes compact all too easily, so sparge and lauter more slowly and carefully than usual to prevent a set mash. It is common for wheat mashes to take up to 50% longer to sparge and lauter than normal mashes.

For breweries equipped with mash vessels and rakes in the lauter tun, working with wheat is much easier. Thorough mashing-in is eased by the agitator in the mash vessel. A short proteolysis rest at 50-52 degrees C (122-125 degrees F) will help run-off by breaking down some of the high molecular weight proteins and gums without excessively degrading foam performance. High mash-off temperatures (76-78 degrees C or 168-172 degrees F) are again beneficial in reducing wort viscosity. In the lauter tun, use the rakes liberally to keep the bed open and draining well. Rake systems that provide a lifting action close to the false bottom help prevent clogging of the slots and are useful in wheat beer brewing.

Regardless of your mashing equipment, wheat worts are turbid and will never clarify as well as normal worts, so recirculate only enough to get the particles out, usually 10-15 min. The high protein content of wheat wort means that the hot break in the kettle is quite spectacular and large amounts of trub are deposited in the whirlpool, so be careful in drawing off the hot wort. Cold break volumes are also relatively large.

Wheat beer fermentations using conventional ale yeasts proceed normally; some brewers feel that wheat proteins are beneficial to yeast nutrition. Excessive foaming may occur in fermentors with insufficient headspace, in which case silicone antifoam agents (available from specialty brewery suppliers) can be used to advantage.

Filtering wheat beers is a matter of personal preference and consumer acceptance. If you must filter, remember that the extra haze makes filtration more difficult. It is often impossible to get good clarity and chill stability without very tight filtration or the use of chill-proofing agents such as silica hydrogel. German wheat beers have very high carbonation levels - 3.0 volumes or so - but such high levels can cause massive problems in brewpub taps. Normal carbonation levels of 2.4-2.7 volumes are very acceptable.


A DYNAMIC STYLE
America wheat beer is an important contribution to the diversity and variety of styles in our young industry. The challenge of wheat beer brewing and the creativity inherent in the style will keep us "wheaties" turning out new variations for many years to come.