[quote=“gusrotteyman”][quote=“deliusism1”]There are numerous factors that can contribute to low mash efficiency- too many to go into in any depth in the span of one post. Someone else here pointed out poor crushing of malt as the single most influential factor. I don’t know if I’d agree that that’s really the #1 biggest factor, but it’s definitely up there in at least the top 3. The other factor that comes immediately to mind for me is temperature control. If the setup you’re using doesn’t guarantee tight control on the temperature of the mash- as in having the ability to sustain a stable temperature with fairly tight tolerances over a long time- that might be your biggest problem. I don’t know what temp you mash at, or what kind of setup you have, but if you think there might be a problem with your system in the area of temperature control, that’s the very first thing I’d try to fix.
Another big area of concern with respect to mash efficiency is hitting the proper pH range of your mash. You’ll hear a few people out there tell you that they don’t bother messing around with mineral additions in their brewing water, or with monitoring mash pH. But I’m here to tell you that it’s really a critical area of concern, and if you haven’t taken the time to get at least a perfunctory understanding of mash chemistry, you really need to. It’s not as daunting an area of research as you might think it is, either. You can go out and buy whole books on the subjects of brewing water chemistry if you want to, but you don’t have to. There are plenty of concise sources of information on the subject available on the web, and even free brewing software programs that you can download that will make it easy to design target water profiles for different styles of beer using simple mineral additions.
Anyway, I don’t want to go on forever :cheers: [/quote]
You may have hit the nail on the head with the temperature control. I use a cooler for this and i do lose about 4.5 degrees over the course of the hour. I also did not start at the correct temp today - it wanted 152 and I was at 150.5. So it could have been the combo of the two that dropped my OG?
I have read online where somebody had the exact same cooler I have and they bought a can of spray insulation and insulated the cooler. Perhaps that will be on my list of upgrades.
Temperature of the mash has a big impact on fermentability, which affects FG, but unless it is WAY WAY off it has very little impact on conversion, which impacts OG. I doubt that is what is causing the problem for you. As deliusism1 stated, pH can also impact conversion, but the effects from that will vary from grain bill to grain bill, and if you are brewing different types of beers you would not be getting the same consistency of the effect due to pH.
I think gdtechvw is exactly right; the crush is the culprit. But rather than trying to change that, just follow Sonex’s advice and plug your past results into Beersmith or some similar brewing program to calculate what your system efficiency is, then just design your recipes using that. You will be spot on for the future.