Tettnanger hops in pilsner and Kolsch style ales

What Tettnanger is

Tettnanger comes from the Tettnang growing region in southern Germany, close to Lake Constance. It is one of the classic noble hops, alongside Saaz, Hallertau Mittelfrueh and Spalt. Alpha acid is low, usually about 3 to 5.5%. Aroma is delicate: herbal, lightly spicy, floral and a little fruity, with a smooth, rounded bitterness.

Low alpha means weight for weight it contributes little bitterness. That is fine. Noble hops are chosen for how they smell and feel, not for how efficiently they bitter. Our guide to noble hops explains the family.

Where it works: pilsner and Kolsch

Two beers show Tettnanger best.

A German-style pilsner is pale, dry and clean, around 4.5 to 5.2% ABV and 25 to 40 IBU. The hop has to carry the beer. Tettnanger gives a soft herbal and floral aroma that is less sharp than Saaz.

Kolsch is an ale fermented warm and lagered cold. It is pale, delicate and slightly fruity from the yeast, usually 4.4 to 5.2% ABV and 18 to 30 IBU. Hop character should be low and floral. Our Kolsch guide covers the style in full. Tettnanger suits it because it stays out of the yeast's way.

The sum: a 1,000 litre Kolsch at 25 IBU

Assume Tettnanger at 4.5% alpha, 28% utilisation for a 60 minute boil and 12% for a 15 minute addition. The working is grams = IBU x litres / (alpha x utilisation x 1,000).

• 60 minutes, 18 IBU: 18 x 1,000 / (0.045 x 0.28 x 1,000) = about 1,430 g.
• 15 minutes, 7 IBU: 7 x 1,000 / (0.045 x 0.12 x 1,000) = about 1,300 g.

That is 2.7 kg of pellets in a 10 hl kettle, which is a lot of plant material for a low IBU beer. Many brewers bitter with a clean high alpha hop and use Tettnanger only for the flavour addition at 10 to 15 minutes. You lose a little tradition and save a lot of trub and wort loss. Our guide to bittering hops for clean lager bitterness covers the first charge.

The floor detail: Kolsch fermentation in the heat

Kolsch yeast likes about 15 to 18 °C and then a cold rest near 0 to 4 °C for a few weeks. In an Indian summer, ambient temperatures in a brewery can sit well above 30 °C, so a fermenter without glycol control will climb. A warm Kolsch throws esters and higher alcohols that fight the gentle hop. If the jacket cannot hold 18 °C, you do not have a Kolsch. You have a fruity pale ale.

Check that the chiller can cope at the hottest part of the day, not on a cool morning. Log the fermenter temperature as well as the set point. A jacket that reads 18 °C at the wall can hide a tank centre a degree or two warmer during active fermentation.

Pilsner detail: water, mash and finish

A pilsner is even less forgiving. Soft water with low sulphate, a mash pH of 5.2 to 5.4 and a lager yeast at 9 to 12 °C. Borewell water in many Indian cities is far harder than a classic pilsner needs, so dilute it with reverse osmosis water or treat it. Residual sulphate makes noble hop bitterness harsh.

Finish with a cold lagering period of three to four weeks. Tettnanger aroma needs that quiet time to settle. Pushing the beer to the tap early gives a green, sulphury nose and wastes a good hop.

Storage and sourcing

Low alpha noble hops lose aroma through oxidation and heat. Buy sealed pellets, keep them frozen and write the crop year on the carton. A carton that sat warm in a storeroom will smell of hay and cheese instead of flowers.

If you cannot get Tettnanger, Saaz or Hallertau Mittelfrueh will do for a pilsner, though each leans differently. Saaz is sharper and more herbal. Hallertau is rounder and more floral.

Why subtle hops are hard to brew with

Subtle hops expose every flaw. There is no big hop aroma to cover diacetyl, sulphur or oxidation. Getting the water, yeast, fermentation temperature and lagering time all right at once is the real work in a delicate beer. It takes mash science, yeast management and packaging control to get the whole thing clean.

Common questions

What does Tettnanger taste like?

Herbal, mildly spicy and floral with a rounded bitterness. It is gentler than Saaz and suits delicate lagers and ales.

Is Tettnanger a good bittering hop?

Not on weight. Its alpha acid is low, about 3 to 5.5%. Most brewers use it late for flavour and bitter with a cleaner high alpha hop.

Can Tettnanger be used in a Kolsch?

Yes. It suits the delicate, floral character of the style, as long as fermentation stays cool enough to keep the yeast esters in check.