As it often happens, interesting beers can be born by accident. It happened to me this time — thanks to a combination of several circumstances. It was quite a chilly day during a severe winter in Poland, even by Polish standards. It was mid-January and the temperature dropped to –20 °C (–5 °F). It was at this time that the taste of the long ago sipped eisbocks like Aventinus and a few iced-beers from Polish craft breweries — like Buba from Szałpiw or a really nice offering from the Cooperative Brewery (Browar Spółdzielczy) — loomed in my head. Tough, oily, warming . . . and treacherous. The perfect sipping beer for a cold winter evening such as I found myself in. So why not create this kind of beer myself?
The weather was just perfect for this task. But which beer style would be great to freeze? Can I finish fermentation in time so that the capricious weather will still be favorable? And so thinking out loud, my lovely wife Maggy, the main brewer in our relationship, threw in the ether — “we still have a Warszawski Porter Bałtycki (Warsaw Baltic Porter) in secondary fermentation, which you promised to bottle last week!” Well, it seems that my procrastination from the previous week made our ready-for-bottling Porter Warszawski a great candidate for the freezing. Thus, from the 20-L (5.25-gallon) batch, 10 L (2.5 gallons) went to bottles and the other 10 L (2.5 gallons) went to freeze.
The base beer itself is an interesting story in its own right. Poland is located on the southern shores of the Baltic Sea, so we refer to Baltic porters as “our” style. It’s a dark but not black beer with ruby reflections, hailing around 22 °P (1.092 SG), using bottom-fermenting yeast (though the style was originally fermented with top fermenting yeast), with hints of coffee, chocolate, plums, finishing at about 9% ABV, yummm . . .
Someone curious may ask — why “Warszawski” (Warsaw)? This is not a meaningless adjective here. The recipe for this beer comes straight from the famed Królewskie Browary Warszawskie (Royal Warsaw Brewery), closed in 2004 by its last owner — Heineken. The last batch of porter from this brewery bears the expiration date — January 2, 2004. What’s special about this particular recipe? Mainly the lack of very dark malts/grains in the mash; with the roasted grain component never exceeding 600 EBC (225 °L) in color. The beer’s final color and additional complexity of flavor is due to the effects of Maillard reactions during a 4-hour boil. The mashing itself also contributes plenty of character thanks to a 2-vessel decoction program.
We froze the porter in a “polypin” 10-L (2.5-gallon) container made of elastic plastic with a tap, which originally was used to referment and serve cask-style ales. With a temperature of approximately 18 to 22 degrees below zero centigrade (0 to -8 °F), the freezing process lasted 3 days. Actually, as it turned out later, we did not have to count on cold weather at all. The home freezer will work just as well! By the end of three cold days and nights much of the water in the porter froze. We yielded about 5 L (1.3 gallons) of Iced Warsaw Porter. The young icy porter, now at an estimated 18% ABV (not tested), has been 8 months in bottle and we are very anxious trying not to open the last remaining bottles.
You can find the recipe and step-by-step to make either the base beer or the iced version on our website at www.byo.com/recipe/warszawski-porter-lodowy