I have a carbonation question/issue.
In my short career, I've done some 2 dozen LME batches that are custom recipes of my LHBS with 100% success regarding carbonation. I've recently moved to partial mash (thanks Deathbrewer!). Although the taste is great, most are almost totally flat. Not all, but the vast majority.
The major difference in my procedure is for my LHBS recipes, I use bottling dextrose which is conveniently portioned out into 8oz bags from the store (this is for 6 gallon batches). I boil 1/2 cup of water and mix the sugar in. I pour that mixture into an empty carboy or bucket, and rack on top, and STIR it gently with the racking cane. Then bottle.
My PMs are 5 gallon batches ( cause online recipes are mostly for 5gal batches). I primary for 2-3 weeks, secondary for another 2. Not wanting to use 8oz which works for 6gal on a 5gal batch, I manually portion out a "heaping" coffee spoon into each bottle with a funnel and fill the bottles. I shake a bit to dilute it. The last time I did it I put more dextrose in than usual, I'm fairly sure I used even more than 8oz total for a 5gal batch. This technique has worked well for my wines.
LHBS recipes typically come with Coopers ale yeast; for my PMs I've been using Safale S05.
My PMs (now 3 attempts) are now 30+ days old and are still flat. Some bubbles, but essentially flat with no head whatsoever.
I'm wondering... is it possible that the act of stirring the beer with the diluted dextrose ensures that viable yeast is properly distributed? Or perhaps the non-diluted dextrose I simply tossed in isn't getting consumed properly by the yeast?
Looking for thoughts/ideas. Thanks!