Saturday, March 10, 2007

Ambient Temperatures in Brewing Ales

Today, I am researching the effects of higher than ideal fermentation temperatures and simple "homemade" solutions to overcome some of these problems.

I recently listened to a podcast from Basic Brewing Radio featuring homebrew author John Palmer. The host James Spencer and John talked about issues of high fermenting temperatures. The gist of it is: High temperatures during fermentation can produce off flavors, but the most important time to have a cooler wort is when pitching. Increases in temperatures after the yeast's growth phase are acceptable, but not too high. From what I have gleaned from research and that podcast is that 90° F (32.2° C) as the absolute maximum temperature, of course this will depend on the yeast used. When I say absolute maximum this is not what I consider an ideal fermentation temperature.

What is deemed most important for hot climate brewing is the pitching temperature. With an ice bucket pre-chiller and immersion wort chiller I will certainly be able to get the wort to 20° prior to pitching the yeast. If I wrap the primary fermenter with some insulation the wort temperature should remain low and fairly constant until the yeast growth phase is complete. After the growth phase is complete the brew temp can increase as long as it doesn't get too warm.

I would like to build an insulated box with a place for an ice tray. I'd need a week's worth of ice, but can make a few bags of ice a day to keep the system cool. This box would allow me to use lager yeast and brew at cooler (10° C) temperatures, but I'd be happy with 15 to 17° C and a nice ale.

So as I build my mini brewery, I will be on the lookout for ways to keep things cool with ice. My shopping list now includes some lengths of copper pipe, a few pieces of garden hose, fittings and a sheet of rigid polystyrene. I know I can get the plumbing parts, but the 'am not sure about the polystyrene. I have seen plans on the web for a brew box that's made of polystyrene. It's rigid and easy to work with. I could also buy or build a wooden box and line it with something. Perhaps something native or spray the inside with insulating foam spray. More things to keep my eyes peeled for.

My next research project is about malting. There is a grains dealer about 4km from the house here. (we're semi-rural) I saw a bag of barley the last time we went past on the jeepney. Hmmm, home malted barley? Pwede!

'till next time...cheers.

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