I like to use the same flour mix as I normally use during the starter feeds/refreshments to build my levain. If you want to make a big change to your levain, I’d recommend taking a small amount of your starter and begin feeding a few times on the new flour feed mix to get the starter used to the new flour. Usually it will adapt and balance out quickly, but sometimes, especially if you’re swapping a higher whole grain flour mix for one with more white flour, you may notice it takes a few feeds to get the starter balanced out and completely active again.You can build your levain 1:1:1, 1:2:2, 1:5:5, or 1:10:10! If you feed lower ratios, plan to have your levain peak and ready to use sooner than if you were to use a higher ratio. What’s nice about a low ratio build is you can have your levain ready to use in just 4-6 hours! What’s nice about a higher ratio build is you can build your levain overnight and have it ready first thing in the morning!I regularly mix up a little extra levain than I need. The reason is two-fold. I often lose a little weight in evaporation. And I find it’s good to have 5-10g extra, so after scooping out the levain there’s always a little left over to propagate and continue refreshments of the active starter.If you want to perform a 1:1:1 feed and need 180g levain, you’ll want to add up the ratio values 1+1+1=3. Then divide the total volume amount by this value (180/3)=60. This gives you your 1X value of 60g. So you would want to mix up (1x) 60g starter + (2x) 60g flour + (2x) 60g water to give you your total 180g levain you need for your bread dough.If you want to perform a 1:2:2 feed and need 180g levain, you’d do the same math: 1+2+2=5. (180/5)=36. So your 1X value in this case is 36g. Mixing up (1x) 36g starter + (2x) 72g flour + (2x) 72g water will give you your total 180g levain you need for your bread dough!