Temperature for Bottling
We're trying to settle an argument here at the brewery and perhaps ya'll could help. Is there an optimal temperature at which to bottle or what would be the the acceptable range? We're unable to access our reference books at the moment. Thanks.
Ideal bottling temp
In my experience 33F - 34F.
It depends on the equipment you are using. If you evacuate the bottles thoroughly first, then counterpressure, then smooth fill with a long tube filler, or very carefully down the bottle walls with a short tube filler, you can get away with a warmer fill than you can if any of these conditions are not met. Probably the most critical aspect though is the dissolved CO2 content of the beer. 33 - 4 deg F sounds a little cold to me, but then I don't know what the filling conditions are like. Basically, fill as warm as you can whilst keeping the beer in the bottle. Typically 4 or 5 degrees C is the max most large filler manufacturers will aim for. Don't forget the aim is to bottle warm so you don't waste energy on refrigeration. Providing it has been stabilised OK, (including really cold storage and filtration) then a couple of degrees C pickup in bright beer tank shouldn't be a problem
Acknowledging that 'the colder, the better", I agree with Dick that stable packaged beer is the objective. I have seen a light lager at 2.7 vol/vol CO2 @ 41degreesF fill fine yet a dark lager at the same gas level on the same filler with identical feed conditions would not @ 38degreesF.
Properly filtered/carbonated/stabilized beer from aging (30-32degreesF?) moving from filter into bright or surge tank should fill fine at 35-38degreesF. It is the inconsistencies of handling that cause many filling headaches. Gushing and malt can go hand-in-hand given processing problems. Turbid beer makes for handling/pumping/filling issues.
Often counter pressure can be adjusted to account for some instability or alternatively fobbing pressure can be altered to account for black fills and some fillers (Krones) have a variety of orifice sizes for snift channels but this is time consuming to alter.
I'm looking for a properly filtered and stabilized (temperature) product with zero bright tank air (the #1 source of air problems at NA micro fillers IMO). If speed causes problems then slowing down should help the problem. The 40/10 Krones filler I had would not run at the spec'd 300 bpm while the 'fill height correction' feature was hooked up even with all there techs on site. The moment we scraped it, it ran fine and was never brought up again. If that was because our beer wouldn't tolerate it (micro-filtered at 2.65 vol/vol at 33degreesF), so be it. The filler needed slight adjustments for ale/lager changes and seasonal humidity issues but nothing major.
If your beer is within your spec, you expect it to fill properly. Equipment is just equipment.